MSC.Marc and MSC.Marc Mentat - MSC Software Corporation

M S C . M a r c a n d M S C . M a r c M e n t a t

Release Guide

Version 2003

Copyright 2003 MSC.Software Corporation

All rights reserved. Printed in U.S.A.

Corporate Europe

MSC.Software Corporation MSC.Software GmbH2 MacArthur Place Am MoosfeldSanta Ana, CA 92707 81829 München, GERMANYTelephone: (714) 540-8900 Telephone: (49) (89) 431 987 0Fax: (714) 784-4056 Fax: (49) (89) 436 1716

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Part Number: MA*V2003*Z*Z*Z*DC-REL

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C O N T E N T SMSC.Marc and MSC.Marc Mentat Release Guide

Contents ■ List of the New Functionalities, 2

■ Description of the New Functionalities, 4

■ Examples of New Functionality, 69

■ List of Defects Fixed in this Release, 71

■ List of Known Problems in this Release, 79

■ Troubleshooting Tips, 84

■ Web Updates for Bug Fixes, 90

■ List of Build and Supported Platforms, 91

■ List of Dropped Platforms, 94

■ Important Notes, 95

■ Platform Specific Notes, 98

■ Security, 102

MSC.Nastran for Windows Release Guide

The release of MSC.Marc 2003 family of products broadly encompasses the following objectives:

• Major new enhancements in several areas in both solver and GUI capabilities

• Substantial improvements in quality – several defects in the previous versions have been fixed

• Notable increase in robustness of analysis

• Notable solver speed improvements

MSC.Marc and MSC. Marc Mentat Release Guide

■ List of the New Functionalities

■ Description of the New Functionalities

■ Examples of New Functionality

■ List of Defects Fixed in this Release

■ List of Known Problems in this Release

■ List of Build and Supported Platforms

■ List of Dropped Platforms

■ Important Notes

■ Platform Specific Notes

■ Security

List of the New FunctionalitiesMSC.Marc 2003

2

I. List of the New Functionalities

There are significant enhancements in various key technology areas in addition to improvements in existing functionality in the MSC.Marc family of products. The extent of the improvements is fairly substantial and spans a broad range of industries. A list of new features for both the solver and graphical user interface is given below. Details can be found in the following section for the enhancements and modifications in both the MSC.Marc and MSC.Marc Mentat 2003 versions.

MSC.Marc 2003

1. Analysis Performance Improvements, 4

A. Direct Sparse Solver Improvements, 4B. Sparse Iterative Solver Improvements, 5C. Other Enhancements for Memory Reduction, 5D. Improvements in Parallel Analysis, 5E. Improvements in Thermal Radiation Calculations, 5F. Improved Convergence in Heat Transfer Analysis, 5G. Analysis Procedure Improvements, 6

2. Contact, 7

A. Thermal Contact, 7B. True Quadratic Contact, 8C. Beam Contact, 9D. Contact Improvements, 10E. Scaling of Rigid Surface, 10F. Separation Controls, 10

3. Electrical/Electronics, 11

A. Piezoelectric Analysis, 11B. Coupled Electrical-Thermal-Mechanical (Joule-Mechanical Analysis), 12C. Improvements in Electromagnetics, 13

4. Element Technology, 14

A. New Reduced Integration Thick Shell Element, 14B. Rebar Element Enhancement, 15C. Continuum Composite Element Enhancement, 15D. Beam Element Enhancements, 16E. Gas Filled Cavities, 16

5. Material Models, 18

A. Anisotropic Plasticity, 18B. Shape Memory Alloys, 19C. Thermo-Mechanical Extensions to Gasket, 21D. Implicit Creep, 22E. Chaboche Model for Viscoplasticity, 24

3List of the New FunctionalitiesMSC.Marc Mentat 2003

6. Automatic Time Stepping Scheme Enhancements, 26

7. Steady State Rolling of Tires, 28

8. Multi-point Constraints, 30

A. INSERT Option, 30B. General Analysis Enhancements – Nonlinear Springs, 30C. MSC.Nastran Rigid Body Elements, 32

9. Global Remeshing and Adaptive Meshing, 33

A. Automatic Global Remeshing with Tetrahedral Elements, 33B. Adaptive Meshing, 34

10. Machining, 36

11. Miscellaneous, 38

A. Axisymmetric to 3-D Analysis Enhancements, 38B. Forming Limit Diagram (FLD) and Principal Engineering Strains, 38C. Large Strain Support for Fracture Mechanics, 40

MSC.Marc Mentat 2003

12. MSC.Marc Mentat Menu Enhancements, 41

13. MSC.Marc Mentat Preprocessing Enhancements, 44

A. Attach, 44B. New Combined Mesh/Geometry Commands, 46C. Modifications to Mesh Generation Commands, 48D. Modifications to the Automatic Meshers, 51E. New Automatic Meshers from MSC.Patran, 52F. Model Parameters, 53G. Multidimensional Tables, 54H. New Table Style Input, 57I. Referencing Tables with Multiple Independent Variables, 58J. Passing a Table Formula to MSC.Marc; Extrapolation Flag, 59K. Electromagnetic Boundary Conditions, 60L. Harmonic Boundary Conditions, 60M. Nodal Ties, Servo Links, and Springs, 61N. Enhancement of Domain Decompositiont, 62O. Job Submission, 63P. Python, 63Q. Miscellaneous Changes, 64

14. MSC.Marc Mentat Postprocessing Enhancements, 66

A. MPEG and AVI Animation, 66B. Post Procedure File, 67C. Merge Contact Model Files, 68D. Generalized XY-Plot, 68

Description of the New FunctionalitiesAnalysis Performance Improvements

4

II. Description of the New Functionalities

1. Analysis Performance Improvements

There are a few major areas where the performance has been substantially improved for large problems in MSC.Marc 2003 release:

A. Direct Sparse Solver Improvements

Storage improvements have been made in the multifrontal sparse solver which should affect all problems. Furthermore, the default optimizer is now Optimize 11 which results in major speed and memory improvements over the previous optimizers.

Figure 1: Comparison of Memory Usage

Figure 2: Comparison of Matrix Solution Time

In Core Memory Use

050000000

100000000150000000200000000250000000300000000350000000400000000

1 2 3 4 5 6 7 8 9 10 11

Size

Mem

ory Optimize 11

Optimize 9

Optimize 10

Matrix Solution Wall Time

0

200

400

600

800

1 2 3 4 5 6 7 8 9 10 11

Time

Siz

e

Optimize 11

Optimize 9

Optimize 10

5Description of the New FunctionalitiesAnalysis Performance Improvements

B. Sparse Iterative Solver Improvements

The sparse iterative solver using Incomplete Cholesky preconditioner has been rewritten to achieve significant improvements in speed. This has been achieved for single as well as parallel analysis as witnessed in Case 1: Sparse Iterative Solver Enhancements.of the New Features Guide 2003.

C. Other Enhancements for Memory Reduction

There have been two major changes in the treatment of memory for large problems, namely:

• The first is a general rewrite of the memory management scheme and contact data structure to improve memory allocation in large problems, with or without contact.

• The second is a contact memory reduction option for cases where only small sliding takes place. In particular for three-dimensional models e.g. automotive engine blocks with large amounts of contact surface data, the memory savings can be significant. Since no significant nonlinear contact behavior is taken into account with this option it does not support friction and coupled behavior. This option can be activated through the CONTACT option or in MSC.Marc Mentat via the button “LINEAR CONTACT WITH REDUCED STORAGE” in JOBS→MECHANCIAL→CONTACT CONTROL→INITIAL CONTACT menu.

D. Improvements in Parallel Analysis

METIS based domain decomposer has been implemented in MSC. Marc Mentat to optimally decompose the domains so as to minimize the nodes on the interdomain boundaries. This results in significant reduction of memory and speed for certain problems with complex geometries.

E. Improvements in Thermal Radiation Calculations

When performing radiation calculations in open or closed cavities, a contribution will be made to the operator matrix based on the information given in the viewfactor file. Depending on the number of faces in the cavity, and the visibility of surfaces, the contribution can substantially increase the bandwidth of the system. A new procedure has been added which uses an implicit/explicit technique based on the magnitude of the viewfactor and a user provided cutoff. For large models (with over 10,000 radiating faces), the improvements can be dramatic.

F. Improved Convergence in Heat Transfer Analysis

If in a heat transfer analysis the external flux is temperature dependent, (e.g. with a temperature dependent film coefficient), then the problem to be solved is nonlinear. In such cases, the speed of the convergence process can be significantly improved by introducing the derivative of the flux with respect to the temperature in the conductivity matrix and in the right-hand-side vector of the set of equations to be solved. This derivative can be entered in user subroutine forcdt.f (point fluxes), flux.f (distributed edge/face fluxes) and film.f (film coefficient).

The procedure can be used in both steady state and transient heat transfer analyses.

Description of the New FunctionalitiesAnalysis Performance Improvements

6

G. Analysis Procedure Improvements

A rewrite has been done for parts of the analysis using the multiplicative decomposition of deformation gradient making analysis significantly faster for lower-order elements. This procedure is activated for plasticity (when using PLASTICITY,5 or choosing LARGE STRAIN MULTIPLICATIVE in the JOBS→MECHANICAL→ANALYSIS OPTIONS menu in MSC.Marc Mentat) or rubber elasticity (when using ELASTICITY,2 or choosing LARGE STRAIN UPDATED LAGRANGE elasticity in the JOBS→MECHANICAL→ANALYSIS OPTIONS menu in MSC.Marc Mentat).

7Description of the New FunctionalitiesContact

2. Contact

Several new Contact features as well as enhancements and improvements to existing contact functionality have been made in MSC.Marc 2003 release, the most notable are:

A. Thermal Contact

Different analysis types are now supported with contact:

– Pure heat transfer analysis.

Compared to previous versions, where a coupled thermo-mechanical analysis was always required to perform a heat transfer analysis with contact bodies, this significantly increases the speed and reduces the amount of memory needed if one is only interested in the heat transfer solution.

– Near Thermal Contact

When bodies are close to one another but are not yet touching, heat can be transmitted between the two surfaces through convection and radiation. The convection can be dependant upon the distances between the two surfaces. This capability has been added to the 2003 release.

– Joule heating (coupled electrical-thermal) analysis and coupled Joule-mechanical (coupled electrical-thermal-mechanical) analysis.

The electrical contact, transmission of current is treated analogously to the transmission of heat.

– In a thermal or coupled thermal-mechanical analysis, heat transfer through small gaps in a model can be taken into account using the near contact option.

Figure 3: Thermal Contact Analysis

Note: Figure 3 shows a temperature as a function of time for two nodes in Contact, one from the Pipe and one from the House. Results are with the Near Contact Option Switched On/Off.

pipe

house

Time (x10000)

node on house near contactnode on house contact

node on pipe near contactnode on pipe contact

Temperature (x100)

Description of the New FunctionalitiesContact

8

In MSC.Marc Mentat, the CONTACT BODIES and CONTACT TABLES menus have been redesigned to easily enter the mechanical, thermal and electric properties of (pairs of) contact bodies.

Figure 4: Thermal Contact Menus

B. True Quadratic Contact

True quadratic contact is now supported for higher-order elements (Figure 5). When quadratic elements were used in previous versions, the geometry and displacement field in the contact area were linearized, which could introduce an inaccurate geometry description and stress solution. Now the complete quadratic geometry and displacement field can be taken into account for various quadratic elements: 6-node triangular and 8-node quadrilateral elements in 2-D and 10-node tetrahedral and 20-node hexahedral elements in 3-D.

It is well known that for quadratic elements a uniform distributed load results in nonuniform equivalent nodal loads. For this reason, the quadratic contact procedure uses a separation procedure which is based on nodal stresses instead of nodal forces.

Figure 5: Advanced Contact Control Menu

9Description of the New FunctionalitiesContact

Activating genuine quadratic contact has three consequences: first, the midside node is now checked for contact with either rigid bodies or the faces of deformable bodies; second, when a node contacts a deformable body composed of higher-order elemetns, the contact will be based upon the true quadratic shape; and third, the normal to the surface will vary along the face.

Figure 6: Quadratic Contact Modeling of Engine Manifold

C. Beam Contact

The new functionality allows beam or truss elements to come in contact with other beam or truss elements (Figure 5). The elements are viewed as straight cylinders with a circular cross-section. The radius of the cross-section, the contact radius, must be provided by the user. Contact is detected if the cylinders touch each other. In that case, a multi-point constraint is automatically imposed that involves the displacements of the beam nodes. The elements can slide with respect to each other (with or without friction). In addition, contact is automatically transferred to neighboring elements if the contacting point slides off the segment.

If a beam slides off a beam, it assumes that it slides to the adjacent beam or else separates from the body. For this reason, the touched beam structure should not have branches.

Since the normal stress is not available for beam elements, the beam-to-beam contact uses a separation procedure and a friction model based on nodal forces.

Description of the New FunctionalitiesContact

10

Figure 7: Beam-to-Beam Contact Examples (a) Model of Pantograph and Overhead Wire (b) Velocity of Overhead Wire at Increment 200

The nodes of beam elements can also come in contact with other continuum and shell elements as well as a rigid body.

D. Contact Improvements

(1) A major rewrite has been done for solving problems involving multibody contact more accurately and without penetration. Cases where nodes have multiple constraints due to touching more than one contact body or due to a combination of contact and kinematic boundary conditions are treated more accurately.

(2) The corner conditions (concave, convex) of 3-D NURBS surfaces (with or without trimming curves) are taken into account.

(3) The iterative penetration procedure has been improved to accurately take into account the complete motion of a (potentially) crossed segment.

E. Scaling of Rigid Surface

Rigid surfaces can be either expanded or contracted during the analysis. This is often useful for modeling inflation or interference fit problems. If no rotation is applied, the scaling can be nonuniform in the x, y, and z-direction.

F. Separation Controls

The 2003 release expands the choices of the criteria used to control separation. It is now possible to prescribe that the separation is based upon either separation or forces, and to define the threshold value in absolute terms or as a fraction of the critical “stress”. This allows the separation to be both independent of the element size and associated with a meaningful physical parameter.

(a) (b)

11Description of the New FunctionalitiesElectrical/Electronics

3. Electrical/Electronics

A. Piezoelectric Analysis

MSC.Marc version 2003 offers the capability to perform a piezoelectric analysis (Figure 8). A material shows a piezoelectric effect if there is a coupling of the mechanical stress and an electric field: the material deforms when an electric field is applied or vice versa, and generates an electric field when it deforms.

The piezoelectric analysis in MSC.Marc is fully coupled, which means that nodal displacements and electric potential are simultaneously solved. To this end, new lower-order 2-D and 3-D elements (element types 160 - 164) have been developed which can be used in static, transient dynamic, harmonic and eigenvalue analysis. The elements can be mixed with existing mechanical elements with linear or nonlinear material behavior. The mechanical material properties for piezoelectric elements can only be linear elastic, but are allowed to be temperature dependent. The electric and coupling material properties are assumed to be constant. Piezoelectric elements can be used in a contact analysis, where, in case of deformable contact between piezoelectric elements, a multipoint constraint equation is set up for both the nodal displacements and the electric potential. The elements also have their equivalent heat transfer elements, so that they can be used in a coupled thermal-piezoelectric analysis.

Possible applications for using the piezoelectric effect are in sensors, transducers and smart materials.

Figure 8: Piezo-electric Properties Submenu

Description of the New FunctionalitiesElectrical/Electronics

12

Figure 9: (a) Principle of Operation of an Ultrasonic Moter (b) Z-displacement as a Function ofthe X-displacement for a Node at the Top of the Stator

B. Coupled Electrical-Thermal-Mechanical (Joule-Mechanical Analysis)

This multi-physics functionality allows the coupling between the electrical, thermal, and mechanical behavior of a structure (Figure 10).

Figure 10: Coupled Electrical-Thermal-Mechanical Analysis

MSC.Marc handles the coupled electrical-thermal-mechanical analysis using a staggered solution procedure similar to the one used in coupled electrical-thermal (Joule heating) analysis and in coupled thermal-mechanical analysis. Using this approach, the electrical problem is solved first for the nodal voltages. Next, the thermal problem is solved to obtain the nodal temperatures. Finally, the mechanical problem is solved for the nodal displacements. Typical applications include actuators, high voltage switches, MEMS devices (Figure 11), and electronic circuits.

The coupling between the electrical and thermal problems is mainly due to the heat generation due to electrical flow (Joule heating). The thermal and mechanical problems are coupled through thermal strain loads and heat generation due to inelastic deformation and friction. Additional coupling may be introduced in case of temperature dependent electrical conductivity and mechanical stiffness. The mechanical problem may involve geometric and material nonlinearities. Contact is another source of nonlinearity. If contact occurs between deformable bodies or deformable and rigid bodies in the mechanical problem, boundary conditions of the electrical and thermal problems are updated to reflect the new contact conditions. Joule heating and coupled electrical-thermal-mechanical capability is available for continuum elements only.

rotor

stator

traveling wave

(a) (b)

orbital of a pointof the stator

13Description of the New FunctionalitiesElectrical/Electronics

Figure 11: Temperature Distribution in a Micro-Electro-Thermal Actuator Array

C. Improvements in Electromagnetics

A change in the number of integration points used for the electromagnetic elements has been made in the 2003 release making them consistent with other elements in MSC.Marc.

The axisymmetric element and some memory allocation problem have been fixed. The default value of the penalty factor (to apply the Coulomb gauge, see Volume A) has been updated to improve the accuracy of the solution, and the permanent magnet option has been fixed.

Post file includes total instead of the incremental potential, as well as external current and charge.

MSC.Marc Mentat menus for solution control and convergence testing have been added.

Description of the New FunctionalitiesElement Technology

14

4. Element Technology

A. New Reduced Integration Thick Shell Element

A new one-point quadrature shell has been developed for linear and nonlinear problems, and replaces the previous element type 140. This new element is a four-node, thick-shell element with global displacements and rotations as degrees of freedom. Bilinear interpolation is used for the coordinates, displacements, and rotations. An MITC4 shell geometry with the ANS (Assumed Natural Strain) method in conjunction with a physical stabilization scheme to construct an element which is free of any spurious modes. The nodal fiber coordinate system at each node is updated with a step procedure in order to consider the warping of the element. A rigid-body projection matrix is applied to extract the rigid-body motion when the element is warped. This element has very good accuracy, reduced memory requirements, and is computationally efficient.

Figure 12: Torsion of a Plate

Figure 13: Impact of a Ball

15Description of the New FunctionalitiesElement Technology

Compared to standard full integration shell elements, this element is computationally efficient in terms of memory and, therefore, very attractive for nonlinear analysis. The element shows excellent performance for large bending and warping (Figure 12) and highly nonlinear analysis including contact (Figure 13).

B. Rebar Element Enhancement

A group of isoparametric rebar membrane elements (types 165 to 170) have been developed. These elements can be embedded into 2-D and 3-D solid elements with the newly developed INSERT option to represent the reinforcing cords or rods in composites. The meshes for solid elements and for the rebar membrane elements can be different. The INSERT option is used to enforce the compatibility between the two meshes. This technique allows much more flexibility in defining rebar properties and orientations (Figure 14), and in pre- and postprocessing.

In the current release both user subroutine rebar.f and REBAR model definition option can be used to define rebar properties simultaneously. The nonzero values defined by rebar.f have precedence over the REBAR option.

Figure 14: Rebar Element Submenu

C. Continuum Composite Element Enhancement

Enhancements to the current suite of mechanical continuum composite elements (149 – 154) include the following:

• Only five layers could be used for the solid composite elements in previous version. This has been increased significantly. Now, the maximum number of layers is 510 for the 3-D elements (element types 149, 150) and 1020 for the 2-D elements (element types 151 – 154).

• Equivalent thermal continuum elements (element types 175 – 180) are introduced in this release. These elements can be used for thermal analysis, heat transfer part of thermo-mechanical coupled analysis, joule heating analysis and electrostatic analysis. The two-dimensional elements (element types 177 – 180) can also be used for magnetostatic

Description of the New FunctionalitiesElement Technology

16

analysis. All heat transfer capabilities except: latent heat, thermal contact (via the CONRAD GAP model definition option), and fluid channel (via the CHANNEL model definition option) are currently supported for the elements. The maximum number of layers is 510 in 3-D and 1020 in 2-D.

D. Beam Element Enhancements

Beam elements 14, 52, 76 to 79, and 98 have been modified to incorporate large rotations. The enhancements also allow the torsional mode to be modeled correctly. The kinematics is now based upon the mid-increment rotations and mid-increment strains, however, the residual force calculation and the coordinates update is done at the end of the increment. This enhancement also allows the beams to model mechanisms.

E. Gas Filled Cavities

This feature allows the modeling of gas filled cavities by automatically updating the volume-dependent cavity pressure as the cavity volume change. Examples of applications for this feature include the modeling of airsprings (Figure 15), tires, lungs, athletic shoes containing air bladders, and any pressure vessel undergoing large deformation.

Figure 15: Airspring Internal Pressure with and without the Cavity Feature

An advantageous aspect of this feature is that the cavity pressure can be directly applied to the structural elements forming the cavity boundary. Thus, if the cavity is completely surrounded by structural elements, no additional elements are required to model the cavity boundary. In regions where the cavity is not enclosed by standard finite elements (e.g. along rigid boundaries), cavity surface elements (elements 171 – 174) can be used. These elements can also be glued to moving rigid surfaces. They are for volume calculation purposes only and do not contribute to the stiffness equations of the model.

By default, MSC.Marc treats the fluid inside the cavity as an ideal gas. The following loading scenarios are available:

(1) Closed cavity: The cavity is assumed to contain a fixed amount of gas and no additional load is applied.

17Description of the New FunctionalitiesElement Technology

(2) Applied pressure: A specified pressure is applied to the cavity.

(3) Applied mass: A specified amount of mass is added to or subtracted from the gas inside the cavity.

The user subroutine, ucav.f allows the user to define and control the cavity pressure for non-ideal gas filled cavities and for loading scenarios other than the ones specified above.

One can obtain the time history of the cavity volumes and pressures using MSC.Marc Mentat.

Figure 16: CAVITIES Menu

Description of the New FunctionalitiesMaterial Models

18

5. Material Models

A. Anisotropic Plasticity

A new yield function based on Barlat’s model, a general criterion for planar anisotropy and particularly suitable for aluminum alloy sheets, has been implemented in MSC.Marc. This criterion has been shown to be consistent with polycrystal-based yield surfaces which often exhibit small radii of curvature near uniaxial and balanced biaxial tension stress states (Figure 17). When compared to the experiments, the Barlat’s model is known to predict the earing phenomenon (Figure 18) more accurately.

For user-friendliness, MSC.Marc Mentat allows either the direct specification of the Barlat coefficients or can extract these coefficients from experimental data (Figure 19).

Figure 17: Comparison of Yield Surfaces for AL 2008-T4 Alloy

Figure 18: Earing Shapes and Contact Contours

Barlat Model Experiment

19Description of the New FunctionalitiesMaterial Models

Multistage return mapping method based on Euler backward method is used for isotropic and anisotropic (both Barlat and Hill) plasticity and is activated by use of PLASTICITY, 4 parameter. Regardless of which PLASTICITY parameter is used to describe the Updated Lagrange procedure, this scheme is always used for the anisotropic plasticity. The combined isotropic-kinematic hardening options can be used for two anisotropic yield functions.

Figure 19: Automatic Calculation for Barlat’s Anisotropic Coefficients

B. Shape Memory Alloys

To simulate the behavior of materials exhibiting shape memory characteristics, two models have been implemented in MSC.Marc:

– Thermo-mechanical Shape Memory Model

– Mechanical Shape Memory Model

Typical uses of such materials are in biomedical devices (stents), airplane-pipe coupling, electrical connectors, thermal actuators, electrical micro-actuators, micropumps in medical applications, and eyeglass frames.

Thermo-mechanical Shape Memory Model

A phenomenological thermo-mechanical constitutive model designed to describe the deformation processes that occur as a result of either pseudo-elastic or shape memory responses of shape memory alloys (e.g. NiTi) has been implemented (Figure 20). The shape memory and directly related phenomena such as pseudo-elastic response, are caused by the inelastic deformations due to nearly reversible phase transformations that, in turn, are associated with deviatoric transformation strains.


20

Figure 20: Shape Memory Material Menus: (a) Thermo-mechanical Shape Memory Model(b) Mechanical Shape Memory Model

The dilatational components of the transformation strains in such alloys are typically small which allow such transformations to occur with little energy dissipation and to thus be capable of near reversibility. The present model describes the development of transformation induced inelastic strains by the austenite to martensite transformation and by additional texturing of martensite. Upon heating, or unloading these materials, the reverse transformation back to austenite occurs, which are at different temperature and stress levels than that of the forward transformation from austenite to martensite.

The shape memory material model is based on decomposing the total strains in term of four contributions: elastic, conventional plastic, thermal strains and strains due to phase transformations. The strains due to phase transformations are in themselves decomposed into two contributions: the TRIP strains (those produced from direct transformation of austenite to martensite, or vice versa) and twinning strains.

Mechanical Shape Memory Model

The second model can only simulate the pseudoelasticity effect but not true shape memory effect.

Since the model is extremely simple and minimum number of input parameters is required, it is easy to use the model for the simulation in the early design stage.

Figure 21 shows the comparison of martensite fraction between thermo-mechanical and mechanical shape memory models


Figure 21: Martensite Fraction: (a) Stent Model (b) Thermo-mechanical Shape Memory Model(c) Mechanical Shape Memory Model

C. Thermo-Mechanical Extensions to Gasket

The gasket option which involved the use of a gasket material model with lower order continuum composite elements with one layer was introduced in MSC.Marc 2003. This option only provided for mechanical behavior with temperature independent through-thickness properties. Also, the temperature loading could only be specified using the NODAL TEMPERATURE or CHANGE STATE options.

In many cases, gaskets have thermally dependent properties and are used in situations where the thermal history is unknown. The extensions to the gasket elements in MSC.Marc 2003 provide the following:

• Gaskets can now be used in mechanical, thermal or thermo-mechanically coupled analysis. For the heat transfer part, the elements used to model the gaskets are type 175 (three-dimensional first-order solid element), type 177 (two-dimensional first-order planar element), or type 178 (two-dimensional first-order axisymmetric element).

(b) (c)

(a)


22

• Through-thickness gasket properties like initial yield pressure, tensile modulus, transverse shear modulus can be specified as a function of temperature and/or spatial coordinates. If necessary, the initial gasket gap can be varied as a function of spatial coordinates. In addition to the mandatory gasket closure distance variable, the loading and unloading paths can also be varied with temperature and/or spatial coordinates. Multi-variate tables can be used to specify these relationships.

Figure 22: (a) Pressure Cooker with a Gasket Separating the Lower Part and Cover(b) Temperature Histories at Different Locations in the Gasket Elements

Temperature histories at different locations in the gasket part of the pressure cooker are shown in Figures 22 (b).

D. Implicit Creep

A number of enhancements have been made to the implicit creep capability in MSC.Marc 2003:

• A fully implicit treatment for power law creep in conjunction with plasticity is now available.

• The yield stress for the plastic component can be varied as a function of the equivalent plastic strain and temperature. Similarly, the back stress for the creep component can be varied as a function of the equivalent creep strain and temperature.

• The coefficients for the implicit power law creep expression can be input directly through the CREEP model definition option or specified through user subroutine ucrplw.f.

• The implicit creep behavior can now be combined with other material behaviors like elastomeric, orthotropic, time-independent elastic-plastic, etc. in the same analysis.

It should be noted that the implicit creep capability is currently available for isotropic materials with a von Mises potential.

(a) (b)


The new MSC.Marc Mentat menu for Implicit Creep (Figure 23) is shown below.

Figure 23: Creep Properties Menu

A CBGA (ceramic ball grid array) mounted onto a PCB (printed circuit board) is cooled down to room temperature from its cure temperature. Figure 24 shows the equivalent creep strain and plastic strain that develop during this process.

Figure 24: Equivalent Strains of a CBGA Mounted onto a PCB

Creep Strain Plastic Strain


24

E. Chaboche Model for Viscoplasticity

Some materials in engineering application may be subjected to cyclic loadings with a stress amplitude greater than the yield stress. To simulate the cyclic plasticity of such materials, a well known Chaboche viscoplasticity model has been implemented in MSC.Marc (Figure 25). The viscous model (strain rate dependency) is based on the unified viscoplastic formulation.

Figure 25: Menu for Chaboche Plasticity Model

Features

The model combines the isotropic hardening rule to describe the cyclic hardening (Figure 26d) or softening, and the nonlinear kinematic hardening to capture the proper characteristic of cyclic plasticity like Bauschinger (Figure 26a), ratcheting (Figure 26b) and mean stress relaxation effect (Figure 26c). Moreover, the influence of the plastic strain range on the stabilized cyclic response is taken into account by introducing the plastic-strain-range memorization variable (Figure 26e).


Figure 26: Characteristic Behavior of Chaboche Plasticity Model

σ

ε

(a) Bauschinger effect

σ

ε

(b) Ratcheting

σ

ε

(c) Mean stress

(d) Cyclic hardening

σ

εε–

(e) Cyclic hardening under

σ

εε–

multiple cyclic loading

relaxation

Description of the New FunctionalitiesAutomatic Time Stepping Scheme Enhancements

26

6. Automatic Time Stepping Scheme Enhancements

A number of enhancements has been made to the AUTO STEP algorithm. These enhancements have been made with a two-fold objective: (a) improved user-friendliness of the time stepping scheme; (b) migration of capabilities of other time-stepping schemes to AUTO STEP so as to provide a unified, robust time-stepping scheme for almost all situations. The enhancements made to improve user-friendliness are as follows:

• Time Step CutbackPrior to MSC.Marc 2003, the time step would only be cut in an arithmetic progression, and for highly nonlinear problems, the number of cutbacks needed would be very large and difficult to estimate apriori.

In the MSC.Marc 2003 release, the number of cutbacks needed to satisfy convergence is now automatically determined by the program. If the solution does not converge within a desired number of recycles, the time step for successive cutbacks is decreased in a geometric progression such that within a program-determined number of cutbacks, the minimum time step is reached.

• User Defined CriterionPrior to MSC.Marc 2003, the user could add appropriate physical criteria based on displacements, stresses, strains, etc. Limits for the physical criteria were not always easy to determine.

In the MSC.Marc 2003 release, an input flag has been provided to allow the program to automatically add suitable physical criteria in the analysis. Suitable physical criteria based on strains, plastic strains, creep strains, etc. are automatically added based on a flag set by the user. The choice to bypass these automatic or manually added physical criteria if they are not satisfied is also provided.

• Stabilization with Quasi-static DampingA quasi-static damping option was introduced with AUTO STEP prior to MSC.Marc 2003 to allow stabilization of non-convergent solutions. This option required the specification of an artificial mass density which was not always easy to determine. This requirement is removed in the current release and the appropriate damping factor needed for static stabilization is automatically determined.

• Time Step Control by the UserDirect control of the time step is possible through use of user subroutine utimestep.f.

The enhancements made to AUTO STEP for a unified load-stepping scheme are as follows:

• Equivalence to AUTO CREEP SchemeAUTO STEP can be used for creep analysis, (in lieu of AUTO CREEP). If an appropriate input flag is set, two physical criteria are automatically added by the program at run-time for explicit creep problems: creep strain increment/elastic strain = 0.5, and stress increment/stress at beginning of increment = 0.5.

• Equivalence to TRANSIENT SchemeAUTO STEP can be used for thermal analysis or thermo-mechanically coupled analysis (in lieu of TRANSIENT). All temperature tolerances that are specified by the TRANSIENT option can now be specified by AUTO STEP, with the additional advantages that physical criteria

27Description of the New FunctionalitiesAutomatic Time Stepping Scheme Enhancements

can be optionally specified with AUTO STEP, and, in coupled problems, AUTO STEP controls the time step based on both thermal and mechanical passes of the run.

• Equivalence to AUTO THERM or AUTO THERM CREEP SchemeAUTO STEP can be used for thermally driven mechanical problems (in lieu of AUTO THERM and AUTO THERM CREEP). The thermal loads derived from a thermal analysis are applied using the CHANGE STATE option in a mechanical analysis. Allowable state variable increments can be optionally prescribed using AUTO STEP either through a user-defined criterion or program determined automatic physical criterion.

• Equivalence to AUTO TIME SchemeAUTO STEP can be used for mechanical dynamic problems (in lieu of TRANSIENT or AUTO TIME). This also has the advantage that unacceptable time integration errors due to large time steps with the Newmark-Beta or Single-Step Houbolt operators are avoided through optional additional checks in the AUTO STEP scheme.

The new menus showing additional options for the AUTO STEP scheme are shown below.

Figure 27: Auto Step Menus

A creep problem solved using automated physical criteria with the auto step scheme is compared to the corresponding solution obtained with the auto creep scheme below.

Figure 28: Examples of Creep Models

Description of the New FunctionalitiesSteady State Rolling of Tires

28

7. Steady State Rolling of Tires

One of the major enhancements of tire modeling in MSC.Marc is the steady state rolling (Figure 29). This presents a better solution to the unnecessary computational burden of arriving at a steady state condition through a transient analysis. The second advantage of a rolling contact model is that a finer mesh needs to be used only in the footprint region as opposed to the whole tire. The feature is characterized by Eularian formulation accounting for the inertia effects in spinning/cornering deformable bodies. With an appropriate choice of reference frame, the analysis becomes purely space dependent. This is in contrast to the Lagrangian formulation where the mesh moves in space, thus incurring a tremendous computational expense.

Figure 29: Steady State Rolling Submenu

Some of the salient features of this functionality are:

1. Inertia effects (centrifugal force and Coriolis force) for spinning/cornering deformation bodies have been taken into account for 3-D lower/higher-order elements (types 7, 84, 117, 120, 9, 18, 21, 35, 57, and 61), as well as 3-D membrane elements (types 9 and 18).

2. The feature can be used with an adaptive time stepping with cutback for various loadcases (AUTO LOAD or AUTO STEP). A specific option of gradual friction increase within a loadcase to enhance the performance for the transition periods from standstill to rolling and from brake to traction is available (Figure 30).

3. In addition to the input in terms of the ground velocity and the tire spinning velocity, a physically more meaningful input for engineers in tire industry, in terms of the ground velocity and the tire axle torque, is available.

4. Rolling contact model currently works only for lower-order 3-D elements with nodal friction.

5. The feature is currently restricted to 3-D analysis.

29Description of the New FunctionalitiesSteady State Rolling of Tires

6. Friction is only available for lower-order elements.

7. Steady state rolling can incorporate rebar element (types 23, 146, 147, and 148).

Figure 30: (a) Tire at Steady State Rolling (b) Rolling Resistance at DifferentSpinning Velocities

(a)

(b)

Description of the New FunctionalitiesMulti-point Constraints

30

8. Multi-point Constraints

A. INSERT Option

An INSERT option is developed to insert a list of elements or nodes into a host body, defined by a list of elements. The degrees of freedom of the nodes in the inserted body are automatically tied to the corresponding degrees of freedom of the nodes in the host body, based on their isoparametric locations.

This option can be used to place reinforcing cords or rods, such as 2-D rebar membrane elements or truss elements, into solid elements. MSC.Marc Mentat can be used to generate rebar membrane meshes compatible to the host body meshes. Possible applications of the INSERT option also include linking two meshes with different degrees of refinement and applying point loads at some specific locations other than element nodes, among others.

Figure 31: INSERT Menu

B. General Analysis Enhancements – Nonlinear Springs

A number of enhancements have been made for springs.

• Linear and nonlinear springs are now available for mechanical, thermal, and electrical analysis.

• Nonlinear springs can be specified using one of two methods:

(1) The spring stiffness (heat transfer coefficient for thermal springs, electrical conductivity for electrical springs) can be specified as a function of up to four independent variables using multi-variate tables. The typical independent variables that can be used are time, normalized time, increment number, displacement (velocity for dashpots, temperature for thermal springs, voltage for electrical spring). In coupled analysis, the spring stiffness can also be made a function of the average link temperature.

(2) The spring force (flux for thermal springs, current for electrical springs) can be specified as a function of up to four independent variables using multi-variate tables. When this option is used, the use of a table as a function of displacement (velocity for

31Description of the New FunctionalitiesMulti-point Constraints

dashpots, temperature for thermal springs, voltage for electrical springs) is mandatory so that the spring stiffness based on the table gradient can be internally calculated. Other variables can include time, normalized time, increment number.

Figure 32: Springs Menu

• Numerical stabilizer flag allows the spring to simply act as a numerical stabilizer without any associated spring forces.

• Spring ID written out in input deck and in post file. This allows convenient processing for DDM and in user subroutine usprng.f.

A sheet-forming problem with nonlinear springs used as drawbeads is shown in Figure 33(a). The nonlinear drawbead force with displacement for a typical spring is shown in Figure 33(b).

Figure 33: (a) Sheet-forming with Nonlinear Springs (b) Nonlinear Drawbead Forcewith Displacement

(a) (b)

Description of the New FunctionalitiesMulti-point Constraints

32

C. MSC.Nastran Rigid Body Elements

In order to enlarge the compatibility with MSC.Nastran, MSC.Marc version 2003 supports the widely used MSC.Nastran rigid body elements RBE2 and RBE3.

They can be used to easily generate rigid connections in a structure or to distribute applied loads on a finite element model and offer additional flexibility compared to the existing tying types in MSC.Marc.

Figure 34: RBE2 and RBE3 Menus

33Description of the New FunctionalitiesGlobal Remeshing and Adaptive Meshing

9. Global Remeshing and Adaptive Meshing

A. Automatic Global Remeshing with Tetrahedral Elements

A new three-dimensional automatic global remeshing capability is added in this release for lower-order tetrahedral element (Figure 35). The feature can be activated using REZONING,2 parameter together with ADAPT GLOBAL option.

MSC.Marc uses the meshing technology in MSC.Patran GS-mesher to create meshes with tetrahedral elements. MOM (Mesh On Mesh) surface mesher and tetrahedral mesher are called separately within MSC.Marc solver to produce the new mesh. MOM mesher uses marching algorithm based on the input triangle mesh. This algorithm is proved to be robust, fast and produces high quality surface meshes. The tetrahedral mesher based on Delaunay triangulation technology is activated after the surface meshing is complete.

Only element type 157 (and type 135 for thermal mechanical coupling) is supported.

Figure 35: Select MSC.Patran Tetrahedral Mesher

The remeshing criteria allow users to specify new element size, control remeshing steps, and convert element type from hexahedral element type 7 to element 157, using IMMEDIATE function and CHANGE ELEMENT TYPE (see Figure 37).

Figure 36: 3-D Tet Remeshing Model

Description of the New FunctionalitiesGlobal Remeshing and Adaptive Meshing

34

Figure 37: Remeshing Control Parameters

The remeshing/rezoning with tetrahedral elements can be used in rigid-to-deformable (Figure 38) or deformable-to-deformable contact but not for problems involving self-contact or with small geometry features.

Figure 38: Turbine Blade Forging

B. Adaptive Meshing

1. Local Adaptivity: Support for Parallel Processing

35Description of the New FunctionalitiesGlobal Remeshing and Adaptive Meshing

The local adaptive feature is now supported in a parallel analysis. An important limitation in this release is that elements that lie along the boundaries between domains for domain decomposition are not allowed to be subdivided. Thus, care must be taken in the domain decomposition so no boundaries occur where elements will be subdivided. The new nodes and elements that are created due to subdivided elements will be in the same domain as the original elements.

2. Local Adaptivity: New User Subroutines

For local adaptivity there are two new user subroutines available:

• uadap2.f allows elements to be unsubdivided. It is called for all active elements, and if all elements that belong to the same parent element are marked for unsubdivide, the parent element is restored.

• uadapbox.f allows the box for the "node within box" criterion to be moved.

Description of the New FunctionalitiesMachining

36

10. Machining

Simulation capability to predict the effects of material removal during manufacturing processes has been added in MSC.Marc 2003. This 3-D bulk machining capability is based on the assumption that effects introduced by the cutting process are local and small compared to those due to insitu residual stresses. The salient features of the machining capability are as follows:

• Seamless integration with CAD files is provided in order to automatically determine the cutter tool shape, cutter motion and other cutter characteristics. The Numerical Control (NC) files that are currently supported include APT and CL files written out from CATIA and APT compilers.

• The elements falling within a composite volume carved out by the moving cutter are automatically deactivated.

• Multiple cutting operations like part flip-overs can be simulated through set-up of appropriate loadcases, each accessing a separate NC file.

• Appropriate preprocessing menus in both MSC.Marc Mentat and MSC.Patran have been added to provide support for the automated element deactivation feature. The user input is primarily the name of the NC file to be used for each loadcase. The menus in MSC.Marc Mentat and MSC.Patran are shown below:

• The deactivated elements are automatically removed from the post files, so that the cutting operation can be visualized.

The limitations of the capability are as follows:

• Elements that are partially intersected by the composite volume are also deactivated if their centroid falls within the volume. This limitation is currently being addressed, where local refinement of the cut elements will be undertaken to improve the fidelity of the cut area.

37Description of the New FunctionalitiesMachining

The deformation of a block with insitu residual stresses after a 2-part machining operation is shown below. Four loadcases have been used in this problem to simulate the first machining operation, the part flip-over, the second machining operation and the final release from the fixture.

Description of the New FunctionalitiesMiscellaneous

38

11. Miscellaneous

A. Axisymmetric to 3-D Analysis Enhancements

The 3-D part of the analysis using AXITO3D option has been parallelized. This can further achieve tremendous savings in computational times.

B. Forming Limit Diagram (FLD) and Principal Engineering Strains

The principal engineering strains can now be calculated based on the true strain values for continuum or shell elements. Correspondingly, the Forming Limit Parameter can be obtained for shell/membranes according to the data of Forming Limit Diagram (FLD) provided by users.

In addition, if shell/membrane elements are used, the Forming Limit Parameters (FLP) can also be selected. The FLP is defined as the ratio of the major principal engineering strain to the maximum allowable major principal engineering strain given by the Forming Limit Diagram.

Figure 39: The Definition of Forming Limit Parameter (FLP)

Preprocessing

The methods employed in MSC.Marc to define the Forming Limit Diagram are: Experimental Data and Predicted FLD Curve.

1. Experimental Data:

There are two input format for the experimental data regarding the FLD of materials: a) Fitted function and b) piecewise linear curve or TABLE definition. The details of the above methods are described as below:

a. Fitted function:

By this method, the polynomial functions are utilized to fit the FLD curve. The functions are shown in MSC.Marc Volume A: Theory and User Information manual.

Major Principal Engineering Strain e1

FLD CurveFLP > 1

FLP < 1 FLP = 1

0Minor Principal Engineering Strain e2

39Description of the New FunctionalitiesMiscellaneous

b. TABLE definition:

The TABLE function in MSC.Marc allows users to define any curves through TABLE model definition option. For example, if user has FLD points of the material, it is possible to define the FLD as piecewise linear curve. See details in MSC.Marc Volume C: Program Input manual.

2. Predicted FLD curve:

The predicted FLD curves are generated based on the theories about local and diffuse necking.

Both theories assume that the material obeys the power-law strain hardening, .

Figure 40: User Interface for Forming Limit (FLD) Data Input

Postprocessing

There are three new post data available for postprocessing of FLD related information (Figure 41):

Forming Limit Parameter (FLP)Major Engineering StrainMinor Engineering Strain

All these data are element based. Users can choose the data type they want to display. For shell/membrane elements, all three data types are available. For continuum elements, only major and minor engineering strains are available.

σ Kεn

=

Description of the New FunctionalitiesMiscellaneous

40

Figure 41: The distributions of (a) Major Engineering Strains, (b) Minor Engineering Strainsand (c) Forming Limit Parameter

C. Large Strain Support for Fracture Mechanics

The J-integral (Lorenzi option) now supports large strains, both in the total and the updated Lagrange formulation. This makes it possible to calculate the J-integral for rubber applications.

(a) (b)

(c)

41Description of the New FunctionalitiesMSC.Marc Mentat Menu Enhancements

II. Description of the New Function

alities

12. MSC.Marc Mentat Menu Enhancements

1. The ATTACH menus have been changed completely in this version of MSC.Marc Mentat. A brief description of the new ATTACH functionality is located in the MSC.Marc Mentat Preprocessing Enhancements section under Attach, and an example of its use can be found in the MSC.Marc New Features Guide.

2. New menus have been added to support the PATRAN TET MESHER under MESH GENERATION→AUTOMESH→SOLID MESHING.

3. The menus for HEXMESH EDGE SENSITIVITY, GAP, SHAKES, and RUNS under MESH GENERATION→AUTOMESH→SOLID MESHING have been moved under ADVANCED CONTROL PARAMETERS.

4. New menus have been added to support the 2D REBAR MESHING under MESH GENERATION→AUTOMESH→2D REBAR MESHING.

5. The DUPLICATE menu under MESH GENERATION has been enhanced so that you can duplicate and group of the following:

In addition, any of the items in the above list may be excluded in the items to be duplicated. The values for CENTRIOD, SCALE FACTORS, ROTATION ANGLES, TRANSLATE, and REPETITIONS are text boxes where the values may be edited conveniently.

6. The EXPAND menu under MESH GENERATION has been enhanced so that you can expand any combination of NODES, ELEMENTS, POINTS, or CURVES. The values for CENTRIOD, SCALE FACTORS, ROTATION ANGLES, TRANSLATE, and REPETITIONS are text boxes where the values may be edited conveniently.

7. The MOVE menu under MESH GENERATION has been enhanced so that you can move:

In addition, any of the items in the above list may be excluded in the items to be moved. The values for CENTRIOD, SCALE FACTORS, ROTATION ANGLES, TRANSLATE, and FORMULAS are text boxes where the values may be edited conveniently.

8. The SYMMETRY menu under MESH GENERATION has been enhanced so that you can use any combination of:

NODES ELEMENTS POINTS

CURVES SURFACES SOLIDS

TIES SERVOS SPRINGS



TIES SERVOS SPRINGS



TIES SERVOS SPRINGS

Description of the New FunctionalitiesMSC.Marc Mentat Menu Enhancements

42

In addition, any of the items in the above list may be excluded in the items to be used in the symmetry operation. The values for CENTRIOD, SCALE FACTORS, ROTATION ANGLES, TRANSLATE, and FORMULAS are text boxes where the values may be edited conveniently.

9. The LINKS menu has been revised to provide MSC.Nastran RBE2 and RBE3 support, a new INSERT links to help in creating rebar meshes. Also, there is no limit on the number of springs or servo links that may be created. For SPRINGS/DASHPOTS, they may now contain properties for MECHANICAL (both STATIC and DYNAMIC), THERMAL or ELECTRICAL and may have tables associated with them. You can also now easily remove all ties or springs.

10. Setting the properties for LAYERED MATERIALS in MATERIAL PROPERTIES have been moved to a submenu under that name.

11. A new menu was added under MESH ADAPTIVITY→GLOBAL REMESHING named PATRAN TETRA which provides access to the new MSC.Patran Tetrahedral mesher.

12. The LOADCASES menu was updated and rearranged. New loadcases include JOULE-MECHANICAL and PIEZO-ELECTRIC loadcases.

13. The JOBS menu was updated with new jobs that include JOULE-MECHANICAL and PIEZO-ELECTRIC.

14. A new menu for STEADY STATE ROLLING PARAMETERS was added under JOBS→ MECHANICAL.

15. New buttons have been added for the commands *set_post_procedure on/off (menu button POST PROCEDURE) and its associated command *post_procedure_file <procedure filename> (menu button FILE) in the RESULTS menu.

16. New menus have been created to support the creation of MPEG and AVI (Windows NT only) movie files. They are located under the RESULTS→MORE→ANIMATION menu as MPEG MOVIE and AVI MOVIE.

17. The PARTICLE TRACKING menu under RESULTS→MORE→PARTICLE TRACKING has been updated to allow for the selection of any SCALAR value that contains the particle tracking information.

18. The RUN JOB menu has been extensively updated in this version of MSC.Marc Mentat.

The job_monitor command is now automatically issued when a job is submitted.

Some buttons are only displayed when certain options are on:

• The USE DDM option is only visible if domains have been created.

• The DDM options for SINGLE MACHINE, NETWORK, and SETTINGS are only visible when the USE DDM option is on.

• The EDIT and CLEAR buttons are only visible when a USER SUBROUTINE has been specified.

43Description of the New FunctionalitiesMSC.Marc Mentat Menu Enhancements

Many of the buttons have been moved to a new submenu ADVANCED JOB SUBMISSION:

• The SUBMIT 2 and SUBMIT 3, and EXECUTE 1-3 buttons.

• The EXTENDED PRECISION button.

• The DCOM and HOSTNAME button.

• The WRITE INPUT FILE and EDIT INPUT FILE buttons.

• The MEMORY ALLOCATION, CHECK SIZES, and OUT-OFCORE ELEMENT STORAGE (elsto) buttons.

New items in the ADVANCED JOB SUBMISSION menu are:

• The SCRATCH DIRECTORY for the job may now be specified. This is where any intermediate files will be created.

• The input file version may now be specified in this menu. The default is DEFAULT STYLE. Previously this option was only available in the JOB PARAMETERS menu.

• The table format may be specified in this menu with the NEW STYLE TABLES button.

The default is the old style table format. Turn on this option to have the input files written out in the new multi-dimensional table style.

19. The PLOT menu has been revised by relocating items to submenus under each available plot setting. The toggle menu to turn on or off the plotting of the items remains in the top menu.

20. The availability of Shape Memory Alloy materials can be found under the MATERIAL PROPERTIES→(MECHANICAL MATERIALS)→MORE→SHAPE MEMORY ALLOY menus.

21. The menus for the creation of structures using the new CAVITY elements can be found under the MESH GENERATION menu.

Description of the New FunctionalitiesMSC.Marc Mentat Preprocessing Enhancements

44

13. MSC.Marc Mentat Preprocessing Enhancements

A. Attach1. MSC.Marc Mentat Preprocessing Enhancements

1. A new attach concept has been implemented in MSC.Marc Mentat. Previously, nodes could be attached either to a point, or to a single curve or to one or two surfaces (the latter via the *attach_node_intersect command). This concept had serious limitations, especially for cases where nodes were lying on multiple curves and/or surfaces. Such nodes could not be associated with all these curves and surfaces.

In the new attach concept, these limitations have been removed by allowing that

– A node can be attached to a point; and

– An element edge can be attached to a curve; and

– An element face can be attached to a surface.

In this setup, nodes can no longer be explicitly attached to curves or surfaces (this will have some effect on existing procedure files, see below). However, every node of an attached edge is now also implicitly attached to the curve to which the edge is attached. Similarly, every node of an attached face is now also implicitly attached to the surface to which the face is attached.

Since nodes can be part of multiple edges and faces, they can now be "attached" to multiple curves and surfaces, by attaching the appropriate edges and faces to the curves and surfaces.Furthermore, a node that is "attached" to multiple curves and/or surfaces is now automatically positioned on the intersection of these curves and surfaces (provided the intersection exists). For example, if a node is part of two edges, the first of which is already attached a curve, then attaching the second edge to a different curve will automatically put the node on the intersection of the two curves.

2. All commands that change the position or shape of points, curves or surfaces reposition the nodes attached to these geometric entities. If for some nodes a new position cannot be found because the curves and surfaces to which the nodes are attached do not intersect, then these commands print an error message in the dialog area and do not change the model. No backup is made in that case.

Note that this is incompatible with previous MSC.Marc Mentat versions, in which some commands did not reposition the nodes if the geometry changed.

3. All commands that modify the coordinates of nodes do not allow nodes to move off the geometric entities to which they are attached. If this happens, these commands print an error message in the dialog area and do not change the model. No backup is made in that case.

Note that this is incompatible with previous MSC.Marc Mentat versions, in which nodes were detached if they were moved to another position. This may have an effect on existing procedure files.

45Description of the New FunctionalitiesMSC.Marc Mentat Preprocessing Enhancements

4. New attach commands have been added:*attach_nodes_point <point> <node list>*attach_edges_curve <curve> <edge list>*attach_faces_surface <surface> <face list>*detach_edges <edge list>*detach_faces <face list>

These commands can be found in the MESH GENERATION→ATTACH menu that has been redesigned.

The *attach_node_point command is retained for backward compatibility but is no longer available via the ATTACH menu.

The attach commands*attach_nodes_curve*attach_nodes_intersect*attach_nodes_surface

are now obsolete, but are retained for backward compatibility. However, the commands will no longer attach the nodes to the geometric entities, but will only move them to the curve, the surface or the intersection of two surfaces. This may affect existing procedure files.

5. A new set of move commands has been added for moving a list of nodes to a point, a curve, a surface or to the intersection of two surfaces, similar to the old attach commands. These commands can be found in the new submenu MOVE TO GEOMETRIC ENTITIES of the MESH GENERATION→MOVE menu. The existing commands for moving points to curves, surfaces, and the intersection of two surface have been relocated to this new menu as well.

6. The commands *attach_elements_curve (ELEMENTS -> CURVE button) and *attach_elements_surface (ELEMENTS -> SURFACE button) have been changed to attach only the first edge of line elements in the list, respectively, the first face of tria and quad elements in the list, and skip the other elements.

7. The algorithm for projecting nodes or points on the intersection of two surfaces has been improved. This may result in slightly different coordinates of the nodes or points compared to previous MSC.Marc Mentat versions.

8. Attached edges are by default drawn in orange and attached faces are drawn in dark blue. These colors can be changed via the VISUALIZATION→COLORS menu.

9. If the drawing of faces is switched off and if initial or boundary conditions are being identified, element edges are now drawn using either the normal edge color or the attach color (whichever is applicable). In previous versions, the edges where drawn using the element face color in this case.

10. The *show_elements (MESH GENERATION->(ELEMS)->SHOW) command now reports for each edge of the element the curve to which it is attached and for each face the surface to which it is attached. The *show_points command reports the number of nodes attached to the point, *show_curves reports the number of edges attached to the curve and the *show_surfaces command report the number of faces attached the surface.


46

11. When reading old-style model files (pre-MSC.Marc Mentat 2003), the old-style attach is converted into new-style attach according to the following rules:

a. If a node was attached to a point in the old style, it will also be attached to that point in the new style.

b. An edge will be attached to a curve if in the old style, all nodes of the edge are attached to either the curve or one of the end-points of the curve.

c. A face will be attached to a surface if in the old style, all nodes of the face are attached either to the surface, or to one of the corner points of the surface, or to a trimming curve of the surface or to a trimming point of the surface.

12. When writing old-style model files, the new-style attach is converted to the old-style attach according to the following rules:

a. If a node is attached to a point in the new style, then it will be attached to that point in the old style as well; otherwise

b. If a node is part of an edge that is attached to a curve, then in the old style, the node will be attached to that curve; otherwise

c. If a node is part of a face that is attached to a surface, then in the old style, the node will be attached to that surface.

d. If a node is part of two faces and both are attached to different surfaces, then in the old style, the node will be attached to both surfaces.

B. New Combined Mesh/Geometry Commands

New commands have been added for moving, duplicating and expanding mesh and geometry simultaneously, while retaining the attach relations between the mesh and the geometry.

1. A command *move_model (MODEL button) has been added to the MESH GENERATION→MOVE menu that moves the entire model (mesh, geometry, and links) according to the specified scale factors, rotations, translations, and formulas.

2. The commands*move_combined <mixed item list>*duplicate_combined <mixed item list>*symmetry_combined <mixed item list>*expand_combined <mixed item list>

have been added to move, duplicate, and expand a mixed list of mesh items, geometric items and links simultaneously. The list of items can be specified by means of graphical picking (single, box, and polygon pick), command line input or the wildcards all_existing, all_visible, all_invisible, all_selected and all_unselected.


By default, all available item types for a given command are pickable and accepted by the command. That is, a box pick will pick every node, element, point, curve, surface, solid, nodal tie, servo link and spring (if applicable, see below) inside the box and pass those on to the command. Similarly, the all_visible wildcard will pick every visible node, element, point, curve, surface, solid, nodal tie, servo link, and spring. The commands

*set_move_combined <item type> on|off*set_duplicate_combined <item type> on|off*set_symmetry_combined <item type> on|off*set_expand_combined <item type> on|off

control the items that are pickable and accepted by a subsequent execution of the corresponding combined command. Here, <item type> is one of

nodeselementspointscurvessurfacessolidstiesservossprings

for the *set_move_combined, *set_duplicate_combined, and *set_symmetry_combined commands and one of

nodeselementspointscurves

for the *set_expand_combined command. For example,*set_duplicate_combined curves off

switches off duplication of curves by the *combined_duplicate command. Curves will not be pickable during the execution of the command and the wildcards will not include any curves.

The *move_combined command preserves the attach relations between the mesh entities and the geometric entities during the move. The *duplicate_combined and *symmetry_combined commands duplicate the attach relations between mesh and geometric entities and the *expand_combined command expands the attach relations. For example, if an edge is attached to a curve then *duplicate_combined attaches the duplicates of the edge to the corresponding copies of the curve, while *expand_combined attaches the faces that result from expansion of the edge to the surfaces that result from expansion of the curve.

These commands can be found in the respective menus in MESH GENERATION (also see the items on these menus on the following pages).


48

C. Modifications to Mesh Generation Commands

Several mesh generation commands that replace existing elements by one or more new elements have been enhanced or rewritten to transfer the attach information from the old elements to the new elements.

1. The CHANGE CLASS operation has been reimplemented. A new command *change_elements_class has been added that replaces the existing *change_elements command. The difference between the two commands becomes apparent when new midside nodes have to be created on edges or faces of elements, for example, to change them to higher-order elements. The old *change_elements command creates multiple coinciding nodes on coinciding edges or faces of different elements that have to be merged by a subsequent *sweep_nodes command. The latter may inadvertedly merge nodes of different regions (contact bodies, for example). By contrast, the new *change_elements_class command first identifies coinciding edges and faces (edges and faces that share the same nodes) and then creates a unique midside node that is shared by the neighboring elements. This implies that a subsequent *sweep_nodes operation is no longer necessary.

A new command *change_elements_linear has been added that changes existing higher-order elements to lower-order, irrespective of their class. Similarly, the new command *change_elements_quadratic changes existing lower-order elements to higher-order. Like the *change_elements_class command, the latter creates unique midside nodes on coinciding edges. The advantage of using these two new commands lies in the fact that changing elements of different classes to their linear or quadratic counterpart can be done in a single operation, and a subsequent *sweep_nodes operation is no longer necessary.

All CHANGE CLASS commands transfer attach information from the original element to the newly created element(s) for all available conversions. Also, when changing to elements of a different family (quad4 to tria3, for example), set information is transferred properly (this used to be wrong in some cases). When changing from first-order element classes to second-order or semi-infinite element classes, the newly created mid-edge nodes are now positioned on the curves to which the edges of the original element are attached, or, if they are not attached to any curve, on the surfaces to which the faces of the edges are attached. The position is determined such that the mid-edge node divides the edge in two parts of equal lengths. When changing to semi-infinite element classes, the newly created midface nodes are now positioned on the surfaces to which the faces are attached (if any). Cases in which the edge is attached to a closed curve or in which the face is attached to a closed surface are handled correctly now. This used to be wrong in previous MSC.Marc Mentat versions. If the nodes of an edge were attached to a closed curve, the mid-edge node could be positioned wrongly if the edge would pass the begin and end point of the curve.

The old *change_elements command can no longer be accessed from the menus, but is retained for backward compatibility.


2. The *convert_curves command now attaches the edges of the line elements to the curves and the nodes at the end points of the curve to the points. Similarly, *convert_surfaces now attaches the faces of the quad elements to the surface and the nodes at the corner points of the surface to the points.

3. The commands *line_expand and *shell_expand now expand the elements in the direction of the normal to the curve or surface to which the first edge or first face of the line elements or shell elements is attached (if any).

4. Subdivide has been completely rewritten to transfer as much as possible of the attach information:

– The nodes created at the position of the corner nodes of the original element will inherit the properties (attach info, sets, initial conditions, boundary conditions, transformations) of the corner nodes.

– For elements with mid-edge/mid-face/mid-element nodes (second-order or semi-infinite element classes), subdivide will create a node at exactly the same position as the mid-edge/mid-face/mid-element node if the latter is attached to a point. These newly created nodes will inherit the properties (attach info, sets, initial conditions, boundary conditions, transformations) of the former in that case.

If the bias factor is zero, any subdivision will create a node at the position of the mid-edge/mid-face/mid-element node of the original element. However, if the bias factor is not zero, this is not always true. In that case, the bias factor will be adjusted a little (for that edge/face/element only) and a warning message will be displayed in the dialog area.

– If an edge of the original element is attached to a curve, the edges of the elements of the subdivision that lie on the edge of the original element will be attached to that curve.

– If a face of the original element is attached to a surface, the faces of the elements of the subdivision that lie on the face of the original element will be attached to that surface.

– If an edge of the original element is attached to a closed curve, the newly created nodes of the subdivision on that edge are now positioned on the part of the curve that is closest to the centroid of the original edge, instead of simply between the curve coordinate of the first node of the edge and the curve coordinate of the last node of the edge, as in previous versions. This fixes a bug that has been present in the code for a long time.

This applies to both the normal *subdivide_elements command and the two special commands *subdivide_elements2hex and *subdivide_elements2quad. In previous versions, the latter didn't transfer any data from the original element to the newly created elements at all.

5. Refine has been completely rewritten to transfer as much as possible of the attach and set information (hence also boundary conditions) from the original element to the new elements:

– Edge and face set information is now transferred from the original elements to the new elements. Consequently, if an edge load is applied to an edge of the original element, the edges of the new elements that lie on that edge will inherit the edge load. Similarly, if a face load is applied to a face of the original element, the faces


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of the new elements that lie on that face will inherit the face load. Node and element set information was already transferred.

– If an edge of the original element is attached to a curve, the edges of the new elements that lie on the edge of the original element will be attached to that curve. If the curve is closed, the newly created nodes on that edge are now positioned on the part of the curve that is closest to the centroid of the original edge, instead of simply between the curve coordinate of the first node of the edge and the curve coordinate of the last node of the edge, as in previous versions. This fixes a bug that has been present in the code for a long time.

– If a face of the original element is attached to a surface, the faces of the new elements that lie on the face of the original element will be attached to that surface.

– For consistency with subdivide, *refine_node now operates in the user coordinate system instead of in the global coordinate system as before. This implies that the resulting subdivision of the original elements depend on the coordinate system type (RECTANGULAR, CYLINDRICAL, SPHERICAL). This may affect existing procedure files.

6. Expansion of axisymmetric meshes to three-dimensional meshes (*expand_axito3d) has been improved to expand attach information:

– If an edge of the axisymmetric mesh is attached to a curve, the faces that result from expanding the edge in the circumferential direction, will be attached to the surface that results from revolving the curve.

– If a node of the axisymmetric mesh is attached to a point, the point is expanded into a circle and the edges that result from expanding the node in the circumferential direction are attached to the circle. If the point is not a trimming point of a surface, the node remains attached to the point. Otherwise, a new point will be created with the same global position as the trimming point and the node will be attached to the new point.

7. The MESH GENERATION menus MOVE, DUPLICATE, SYMMETRY, and EXPAND have been redesigned. Displays have been replaced by editable text fields, so that the parameters that govern these operations (centroid, scale factors, rotation angles, etc.) can be set individually.

Commands:*set_move_trans_from_to <x1> <y1> <z1> <x2> <y2> <z2>*set_duplicate_trans_from_to <x1> <y1> <z1> <x2> <y2> <z2>*set_expand_trans_from_to <x1> <y1> <z1> <x2> <y2> <z2>

have been added to set the translation vector T for move, duplicate, and expand operations, respectively, to the relative position of (x2, y2, z2) with respect to (x1, y1, z1), that is

T = (x2 - x1, y2 - y1, z2 - z1).

Both (x1, y1, z1) and (x2, y2, z2) may be entered by clicking on grid points, points, or nodes. The commands are useful if one wants to move items from one point in the model to another.


Similarly, the new command*set_symmetry_plane_normal_from_to <x1> <y1> <z1> <x2> <y2> <z2>

sets the normal vector N for symmetry operations to the direction from (x2, y2, z2) to (x1, y1, z1), that is

N = (x2 - x1, y2 - y1, z2 - z1) / ||(x2 - x1, y2 - y1, z2 - z1)||.

Again, both (x1, y1, z1) and (x2, y2, z2) may be entered by clicking on grid points, points, or nodes.

8. Duplication of trimmed surfaces has changed. Previous MSC.Marc Mentat versions did not create exact copies of the trimming points and trimming curves of a surface. For each trimming curve, the complete set of points was duplicated, even if some of these points were shared by other trimming curves of the same surface. For example, if two trimming curves of the original surface had an end point in common, this was not the case for the duplicates. Two points were created at the same position in that case. This is fixed in MSC.Marc Mentat 2003. The trimming points and curves are now duplicated exactly. However, this means that a different number of trimming points may be created when duplicating trimmed surfaces and may affect existing procedure files.

This applies to all DUPLICATE and SYMMETRY commands that copy trimmed surfaces.

9. The curves and surfaces created by the *symmetry_curves and *symmetry_surfaces commands now have the same orientation as their originals. This is incompatible with previous MSC.Marc Mentat versions, in which the new curves and surfaces were flipped compared to the originals. The command

*set_symmetry_geometry_old on

restores the old (pre-MSC.Marc Mentat 2003) behavior of these commands and should be called in existing procedure files prior to such a symmetry operation, to ensure that the procedure file still produces the same model.

D. Modifications to the Automatic Meshers

The automatic meshers have been enhanced for the new attach concept.

1. The 2-D meshers now attach all edges on the boundary of the mesh to the appropriate curves. Both the advancing front mesher and the overlay mesher also attach nodes that are located on the end points of the curves to these points.

2. The surface meshers now attach all element faces to the surface and attach all edges on the boundary of the mesh to the appropriate trimming curves. Both the advancing front mesher and the overlay mesher also attach nodes that are located on the end points of the trimming curves to these points.

3. The overlay mesher has been modified to compute the sizes of the elements in the U- and V-directions in a more intuitive way that is also more in agreement with the hexahedral mesher. In previous MSC.Marc Mentat versions, the mesher would create a rectangular grid on a square region that just covers the region to be meshed, using the overlay divisions in the respective directions. If the number of divisions in U- and V-directions were equal, square elements would result. In MSC.Marc Mentat 2003, the


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element size in U-direction is computed independently of that in the V-direction as the ratio of the largest U-dimension of the region and the overlay divisions in U-direction. The element size in the V-direction is determined similarly. This greatly improves meshing of slender regions.

As a result, MSC.Marc Mentat 2003 may produce a different mesh for a given geometry and overlay divisions than previous MSC.Marc Mentat versions. The command

*set_overlay_old_div on

restores the old (pre-MSC.Marc Mentat 2003) behavior of the mesher. This command should be called in existing procedures files prior to the mesher to ensure that the procedure file still produces the same model.

4. The tetrahedral mesher and the new MSC.Patran mesher attach element faces on the surface of the tetrahedral mesh to the surfaces to which the faces of the original surface mesh were attached.

E. New Automatic Meshers from MSC.Patran

The MSC.Patran Mesh-on-Mesh (MOM) surface mesher and tetrahedral solid mesher are now available in MSC.Marc Mentat. This mesher is fast and can handle complex geometry much better than the standard MSC.Marc Mentat mesher.

1. MSC.Patran Mesh-on-Mesh Surface Mesher

The surface mesher can be accessed through menu MESH GENERATION→ AUTOMESH→SURFACE MESHING→PATRAN SURFACE MESHER. This function is used for remeshing the given list of surface triangle elements or geometry defined by triangles such as that in STL format.

The element size for surface mesher can be set through the button ELEMENT SIZE. If the element size is set to 0, the average size of the input elements will be used. The new elements will have edges of approximately this length.

In addition to the mesher size, there are 2 more parameters the user can use to control the feature of mesh. They are feature edge angle and feature vertex angle and can be set in the ADVANCED menu through button FEATURE EDGE ANGLE and FEATURE VERTEX ANGLE.

If the angle between normal vectors of two neighboring surfaces of an edge is larger than feature edge angle, the edge will be considered as a soft feature edge. A soft edge will be kept after the remeshing but new nodes can be placed on the edge.

If two feature edges join at a point and the angle between the two feature edge vectors pointing outward of the point is smaller than feature vertex angle, the point will be considered as a hard point. A hard point will be kept as an element node after remeshing.

2. MSC.Patran Tetrahedral Solid Mesher

The solid mesher can be accessed through menu MESH GENERATION→AUTOMESH → SOLID MESHING→PATRAN TET MESHER. This function is used for meshing the volume defined by the given list of triangle surface elements. The input surface elements must completely enclose the volume to be meshed. The coarsening factor can be used to gradually enlarge the tetrahedral element size from the surface to the interior region.


The coarsening factor can be set through the button COARSENING FACTOR. The elements will be enlarged by this factor from the surface to the interior layers. The default is 1.5.

F. Model Parameters

1. The following commands that set the value of model parameters will now check by default the validity of the value before changing the parameter:

BOUNDARY CONDITIONS menu:*apply_value*apply_param_value (NEW)*apply_variable*apply_post_increment*apply_post_steps

INITIAL CONDITIONS menu:*icond_value*icond_param_value (NEW)*icond_variable*icond_post_increment*icond_post_time*icond_exp_repetitions

LINKS→SPRINGS menu:*link_value*spring_param (NEW)*spring_multi_param (NEW)*link_multi_spring_stiffness*link_multi_spring_damping*link_multi_spring_init_force

CONTACT→CONTACT BODIES menu:*contact_value

CONTACT→CONTACT TABLES menu:*contact_table_property

LOADCASES menu:*loadcase_value

JOBS menu:*job_param

If the value is outside the valid range of the parameter, an error message is displayed in the dialog area and the parameter is not changed. This allows MSC.Marc Mentat to detect any user errors as early as possible. The command

*set_model_validation on|off

can be used to switch range checking off. If it is switched off, the above commands also accept values outside the valid range of the parameter. This may be useful if a parameter is used in a non-standard way.


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G. Multidimensional Tables

1. Independent Variables

The tables in MSC.Marc Mentat have been enhanced to allow multiple independent variables.

In previous versions, tables had 1 independent variable. The physical meaning of the independent variable was defined by setting the table type.

In this release, a table may have up to 4 independent variables, each having a different physical meaning. The type must be set for each independent variable individually. Use the button TYPE (command: *set_md_table_type <indep_var> <type>) to set the type for the current independent variable.

Note that for tables with multiple independent variables, the current independent variable in the menu can be changed using the INDEPENDENT VARIABLE pulldown menu.

The number of available types has been increased. Also, the names of some types have been changed:

The old command *set_table_type can still be used to set the type for tables with 1 independent variable. Note that this command still expects the old table type names, which means that this command will be processed correctly if old procedure files are run. When reading an old model file or table file ("normal" format), the old types are mapped automatically to the new types. The inverse operation is done when saving a model in an older format.

The independent variables are referred to as v1, v2, v3, and v4. In previous versions, the independent variable was referred to as x.

The number of steps and the range used to plot the axis of the current independent variable can be set using the buttons STEPS (command: *set_md_table_step_v <indep_var> <nsteps>), MIN (command: *set_md_table_min_v <indep_var> <vmin>) and MAX (command: *set_md_table_max_v <indep_var> <vmax>) from the INDEPENDENT VARIABLE menu section.The MORE button must be used to access the buttons LABEL (command: *set_md_table_label_v <indep_var>) and FORMULA (command: *set_md_table_formula_v <indep_var>) from the INDEPENDENT VARIABLE menu section, that allow changing the label displayed along the axis of the current independent variable.The old commands *set_table_xstep, *set_table_xmin, *set_table_xmax, *set_table_xname, and *table_xformula may still be used for tables with 1 independent variable. Note that the old command *table_xformula still expects a

plastic_strain has been renamed to eq_plastic_strain

stress has been renamed to eq_stress

strain rate has been renamed to eq_plastic_strain_rate

gasket_closure rate has been renamed to gasket_closure_distance

stress_rate has been corrected to eq_stress


formula expressed in x and then converts the formula to v1, which means that this command will be processed correctly if old procedure files are run. When reading an old model file or table file ("normal" format), the label formula in x is automatically converted into a formula expressed in v1. The inverse operation is done when saving a model in an older format.

2. Dependent Variables

For most tables, the number of dependent variables is 1. The exception is formed by tables for experimental data fitting that may have 2 dependent variables. The number of independent variables for these tables is always 1. Tables with 2 dependent variables were already supported in previous MSC.Marc Mentat versions, but they could only be created by reading raw table data. Moreover, the second function value could neither be displayed nor edited. In this release, tables with 1 independent and 2 dependent variables can be created in MSC.Marc Mentat, and the second function value can now be displayed and edited.

Note that for tables with multiple dependent variables, the current dependent variable in the menu can be changed using the FUNCTION VALUE pulldown menu.

The dependent variables are referred to as f and f2. In previous versions, the dependent variable was referred to as y.

The number of steps and the range used to plot the axis of the current dependent variable can be set using the buttons STEPS (command: *set_md_table_step_f <dep_var> <nsteps>), MIN (command: *set_md_table_min_f <dep_var> <fmin>) and MAX (command: *set_md_table_max_f <dep_var> <fmax>) from the FUNCTION VALUE menu section.

The MORE button must be used to access the buttons LABEL (command: *set_md_table_label_f <dep_var>) and FORMULA (command: *set_md_table_formula_f <dep_var>) from the FUNCTION VALUE menu section, that allow changing the label displayed along the axis of the current dependent variable.

The old commands *set_table_ystep, *set_table_ymin, *set_table_ymax, *set_table_yname, and *table_yformula may still be used for tables with 1 independent variable. Note that the old command *table_yformula still expects a formula expressed in y and then converts the formula to f, which means that this command will be processed correctly if old procedure files are run. When reading an old model file or table file ("normal" format), the label formula in y is automatically converted into a formula expressed in f. The inverse operation is done when saving a model in an older format.

3. Creating a Table

When creating a table, use the NEW button to open up the NEW TABLE pulldown menu, and select one of the buttons to set the number of independent and dependent variables (command: *new_md_table <# indep_vars> <# dep_vars>). The old command *new_table can still be used to create a table with 1 independent and 1 dependent variable.


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4. Reading and Writing Table Data

Another way of creating a table is by reading data from a file. Two file formats are available for reading (and writing) table data.

The "raw" format (commands: *md_table_read_raw <file name> and *md_table_write_raw <file name>) can only be used for tables with 1 independent variable. Each line in the raw file represents one table point. The first column contains the value of the independent variable, the second column contains the value of the dependent variable (function value). For tables with 2 dependent variables, a third column contains the second function value.

The "normal" table file format (commands: *md_table_read <file name> and *md_table_write <file name>) has been enhanced to contain all data of the new multidimensional tables. The old commands *table_read and *table_write may still be used to read and write data for tables with 1 independent variable and 1 dependent variable using the "normal" table file format of the previous MSC.Marc Mentat versions.

5. Multiplying Tables

A third method has been added to create a table: multiplication of two tables. The number of independent variables of the new table is the sum of the number of independent variables of the two original tables. If the sum exceeds 4, the operation is not performed. The function values of the new table are computed as Fnew(v1, v2, v3) = F1(v1) * F2(v2, v3).

6. Data Points vs. Formula

Apart from reading data points from a file, table points can be generated by adding data points manually or evaluating a formula.

Adding data points manually for tables with 1 independent variables must be done using ADD (command: *table_add). The user must enter the value of v1 and f (and f2 in case of 2 dependent variables). This command existed already in previous versions of MSC.Marc Mentat and can be repeated as often as needed.Adding data points manually for tables with multiple independent variables must be done using the new command ADD ALL POINTS (command: *md_table_add_all). The user is prompted for the number of data points for each independent variable.Next, the user must enter the values of each independent variable. Finally, the user is expected to enter all function values. Note that currently for tables with multiple independent variables, no new data points can be added if data points already exist.

To enable the use of a formula, the user must now first select FORMULA (command: *set_md_table_method_formula). Then, the ENTER button must be clicked and a formula must be given expressed in v1, v2, v3 and/or v4 (command: *md_table_formula). Data points are created by evaluation of the formula using the number of steps and the range for each independent variable. Reevaluation of the formula is done using REEVALUATE (command: *md_table_reeval).The old commands *table_formula and *table_reeval may still be used for tables with 1 independent variable. Note that the command *table_formula still expects a formula expressed in x and then converts the formula to v1, which means that this command will be processed correctly if old procedure files are run. When reading an old


model file or table file ("normal" format), the formula in x is automatically converted into a formula expressed in v1. The inverse operation is done when saving a model in an older format.

7. Plotting

The FILLED option for table plots is now off by default.

For tables with more than 1 independent variable, the X-AXIS pulldown menu has been added to select which independent variable is displayed along the X-axis of the plot. The other independent variable is displayed along the Y-axis of the plot. A curve is drawn for each data point value of the independent variable that is displayed along the Y-axis.

For tables with more than 2 independent variables, the Y-AXIS pulldown menu has been added to select which independent variable is displayed along the Y-axis of the plot. For the third independent variable, a fixed value is taken, namely the i-th data point value for this independent variable. The index i ranges from 1 to the number of data points of the independent variable and can be set using the FIX button (command: *set_md_table_fix_index <indep_var> <i>).

For tables with 4 independent variables, a second FIX button has been added to fix the value of the fourth independent variable.

8. Data Storage

The data storage of tables has been enhanced to use dynamic memory allocation. Previous versions used fixed size arrays to store the data point values, the number of data points being limited to 1001.

H. New Table Style Input

The new multidimensional tables have been designed to support the new table style input of MSC.Marc. However, this new style input is not the default input style of this release. It can be activated by switching on the NEW-STYLE TABLES toggle (command: *job_option input_style:new). This button is available in the JOBS→...→JOB PARAMETERS menu and the JOBS→RUN→ADVANCED JOB SUBMISSION menu.

The menu items supporting MSC.Marc input options that are only available in combination with the new style input are hidden by default. To fully uncover all possibilities of the new style input, MSC.Marc Mentat must be run using a different binary menu file. To create this binary menu file, go to the directory where MSC.Marc Mentat is installed and enter the following command:

./bin/mentat -df NEW_INPUT -compile menus/new.msb

To run MSC.Marc Mentat using this binary menu file, enter the following command:

mentat -mf new.msb


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I. Referencing Tables with Multiple Independent Variables

When new style input is used, tables with multiple independent variables may be referenced by any parameter for which a TABLE button is available.

If the default style input is used, tables with multiple independent variables may only be used for a limited set of parameters:

– Material parameters previously referring to multiple tables (see below)

– Equivalent creep strain rate (see below)

– Gasket material parameters

– Spring parameters

1. Material Parameters Previously Referring to Multiple Tables

In previous versions, the user could assign multiple tables to the following material parameters:

PLASTICITY material:INITIAL YIELD STRESS (commands: *material_table plasticity:yieldstress0|1|2)10TH CYCLE YIELD STRESS (commands: *material_table plasticity:yieldstress100|1)

FLUID material:VISCOSITY (commands: *material_table fluid:nt_viscosity0|1)

POWDER material:YOUNG’S MODULUS (commands: *material_table powder:youngs_modulus0|1)POISSON’S RATIO (commands: *material_table powder:poissons_ratio0|1)CONDUCTIVITY (commands: *material_table powder:conductivity0|1)SPECIFIC HEAT (commands: *material_table powder:specific_heat0|1)

In the current release, a parameter can only have 1 table assigned to it (commands: *material_param_table plasticity:yield_stress, etc.).

For the material parameters mentioned above, this means that a table with multiple independent variables must be selected in cases where previously multiple tables would have been selected.

If, during reading of an old model file, any of the above mentioned parameters is found that references multiple tables, a new table with multiple independent variables is automatically created and assigned to this parameter. This new table is created by multiplication of the tables that were being referenced by the parameter, as discussed in the section "Multiplying Tables".

Note that old procedure files, in which multiple tables are assigned to any of the above mentioned parameters, will not run correctly anymore. Edit the procedure file such that the tables are multiplied and the resulting table is assigned to the parameter.


2. Equivalent Creep Strain Rate

In previous versions, the dependency of the equivalent creep strain rate on stress, creep strain, temperature, and time could be defined separately. For each dependency, the user could choose between a power law formulation or a piecewise linear formulation referencing a table (commands: *material_option creep:stress:power|series, etc.). As a consequence, the user could reference up to 4 tables to define the creep behavior (commands: *material_table creep:stress_exp0, etc.). In the current release, this has been changed. There is one option to switch between power law and piecewise linear (command: *material_option creep:method:default|pwlinear), and only 1 table can be referenced for the piecewise linear method (command: *material_param_table creep:coefficient).

This means that, for creep material definition, a table with multiple independent variables must be selected in cases where previously multiple tables would have been selected.

If, during reading of an old model file, a creep material definition is found that references multiple tables, a new table with multiple independent variables is automatically created and assigned to the "coefficient" parameter.

This new table is created by multiplication of the tables that were being referenced in the old material definition , as discussed in the section "Multiplying tables". In addition, the material option "method" is set to "pwlinear" if any of the dependencies was using the piecewise linear method.

Note that old procedure files, in which multiple tables are referenced in a creep material definition, will not run correctly anymore. Edit the procedure file such that the tables are multiplied and the resulting table is assigned to the "coefficient" parameter, and make sure the material option "method" is set to "pwlinear".

J. Passing a Table Formula to MSC.Marc; Extrapolation Flag

When new style input is used, tables defined by means of a formula instead of a set of data points are treated differently. The formula is passed to MSC.Marc, which evaluates the tables during the analysis. To activate this feature, the table method must be set to FORMULA (command: *set_md_table_method_formula) and a formula must be given in terms of v1, v2, v3 and/or v4. If the formula method has been used to create data points but the formula should not be passed to MSC.Marc while using the new style input, you must set the table method back to DATA POINTS (command: *set_md_table_method_data_points).

When new style input is used and the table method is set to DATA POINTS (command: *set_md_table_method_data_points), the user may indicate for each independent variable whether MSC.Marc must perform extrapolation of data in case the independent variable value is outside the range of data points (command: *set_md_table_extrap <indep_var> on). If this option is off, the value at the closest data point is taken.

If the default input style is used, the use of both these features is only allowed for:

Gasket material parametersSpring parametersForming limit parameter (Table method)


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K. Electromagnetic Boundary Conditions

Four new boundary condition types have been added such that the old types

FIXED POTENTIAL (*apply_type fixed_elma_potential) andPOINT CURRENT-CHARGE (*apply_type point_current_charge)

could be split up in two types each:

FIXED ELECTRIC POTENTIAL (*apply_type fixed_elma_elec_potential),FIXED MAGNETIC POTENTIAL (*apply_type fixed_elma_magn_potential),POINT CHARGE (*apply_type elma_point_charge) andPOINT CURRENT (*apply_type elma_point_current).

This allows defining the electric and magnetic boundary conditions independent of one another.

Upon importing old model files, the old types are converted to the new types. If a model file must be written in a pre-2003 style, it is advisable to change the new types of electromagnetic boundary conditions to the old types before saving the model.

L. Harmonic Boundary Conditions

The modeling of boundary conditions for harmonic loadcases has changed. In this release, separate boundary condition types for harmonic excitations have been added. These new types can be found in the HARMONIC BC’s submenus of the MECHANICAL, ELECTROSTATIC, ACOUSTIC, and ELECTROMAGNETIC boundary condition menus.For these new types, the user may now set the INPUT MODE to either MAGNITUDE & PHASE or REAL & IMAGINARY (command: *apply_option harmonic_mode:magn_phase|real_imag).

Harmonic boundary conditions can only be selected in harmonic loadcases. They cannot be selected in loadcases of other types, nor can they be selected as initial load.

In a harmonic loadcase, the user may select both harmonic boundary conditions and normal boundary conditions. A normal boundary condition has a constant value during the harmonic loadcase, while a harmonic boundary condition represents a load that is oscillating at the current frequency.

In previous MSC.Marc Mentat versions, all boundary conditions selected in a harmonic loadcase were considered to be harmonic boundary conditions. Also, in previous versions, the phase angle of a harmonic boundary condition could be set per loadcase; this is no longer the case as the phase is now set for a boundary condition. It is possible though to assign a table of type "time" to the magnitude, phase, real part and imaginary part.

When reading older model files, the type of boundary conditions only used in harmonic loadcases is changed to the equivalent new harmonic type, and the phase is inherited from the harmonic loadcase.If a model file must be written in a pre-2003 style, it is advisable to change the types of harmonic boundary conditions to their non-harmonic equivalents before saving the model.Please check carefully if old procedure files, in which harmonic boundary conditions are applied, are still running correctly.


M. Nodal Ties, Servo Links, and Springs

Several enhancements have been made to the support for nodal ties, servo links, and springs.

1. The limitations on the number of retained nodes for user defined tyings (via user subroutine UFORMS) and the number of terms for servo links has been removed. These multi-point constraints can now have any number of retained nodes. In previous MSC.Marc Mentat versions, the limit was 9.

2. The LINKS→NODAL TIES, LINKS→SERVO LINKS, and LINKS→SPRINGS menus have been redesigned. Displays have been replaced by editable text fields and buttons have been introduced for setting the degrees of freedom of a servo link or spring node.

3. New commands have been added to move, duplicate, duplicate by reflecting with respect to a plane (symmetry) and remove lists of nodal ties, servo links and springs. These lists can be specified by means of graphical picking (using the usual single pick, box pick, or polygon pick methods), command line input, or the wildcard all_existing. The wildcards all_invisible and all_selected are not yet available for links; the wildcards all_unselected and all_visible are currently identical to all_existing.

The new remove commands:*remove_ties <ties list>*remove_servos <servos list>*remove_springs <springs list>

can be found in the LINKS→NODAL TIES, LINKS→SERVO LINKS, and LINKS→SPRINGS menus, respectively.

The new move commands:*move_ties <ties list>*move_servos <servos list>*move_springs <springs list>

duplicate commands*duplicate_ties <ties list>*duplicate_servos <servos list>*duplicate_springs <springs list>

and duplicate by symmetry commands

*symmetry_ties <ties list>

*symmetry_servos <servos list>

*symmetry_springs <springs list>

can be found in the respective menus in MESH GENERATION (also see the items on these menus below). The new mesh generation commands behave similar to the corresponding commands for elements.

4. MSC.Marc Mentat will now draw lines between the tied node and all nonzero retained nodes of nodal tyings and servo links. Previously, these lines were drawn only between the tied node and the first nonzero retained nodes, until a zero retained node was found.


62

N. Enhancement of Domain Decompositiont

1. The Domain Decomposition are enhanced by 3 new methods:

– Metis Element Based,

– Metis Node Based, and

– Metis Best (combined Metis Element Based and Metis Node Based).

These 3 methods are based on the implementation of the well known Metis Graph Decomposition Methods.

2. Metis based methods are robust and produce good quality domains.

3. The former DECOMPOSE button is now represented by the Geometric DDM method. The former GENERATE button is now represented by the Simple DDM method.

The actual decomposition is performed by the GENERATE! button.

Figure 42: Domain Decomposition Menu and Example Model


Figure 43: Domain Decomposition Menu with Pop-up Metis Buttons

O. Job Submission

MSC.Marc jobs are now run from the directory in which the model file was read. The log file, scratch files, and the post file will be created in that directory. The SET DIRECTORY command has no effect on the location of these files. The location for the scratch files may be changed using the scratch_directory command in the JOBS→RUN→ADVANCED JOB SUBMISSION menu.

P. Python

The ability to obtain a user-defined string from MSC.Marc Mentat in a Python script has been added. The user can specify the string using the PARAMETERS menu, and the Python script obtains the value using the py_get_string routine. The following example uses the model file in Chapter 7 of the MSC.Marc Python Tutorial and prints out the number of sets in the model. The steps for this example are:

– Browse to the Python examples directory.

– Specify the name of the model file that we want to check.

– Run the Python script.

UTILSCURRENT DIRECTORY

mentat2003/examples/python/tutorial/c07OK

PARAMETERS(NAME)

filename


64

(EXPRESSION)sets.mfd

OKPYTHON

RUNnsets.py

The Python script is:

1 from py_mentat import *23 def main():4 fn = py_get_string("filename")5 s = "*open_model %s" % fn6 py_send(s)7 n = py_get_int("nsets()")8 print "Sets found: ",n9 return1011 if __name__ == ’__main__’:12 main()

The output of the script will be printed in the terminal window:13Sets found: 8

Q. Miscellaneous Changes

1. All commands that use bias factors now display an error message in the dialog area if one of the bias factors is invalid, that is, if the bias factor less than or equal to -n/(2*(n-1)) or greater than or equal to n/(2*(n-1)), where n is the number of subdivisions. The model will not be changed in that case and no backup will be made. The affected commands are:

MESH GENERATION→CONVERT menu:

*convert_curves

*curve_polylines

*curve_interpolated

*convert_surfaces

*surface_polyquads

*surface_interpolated

MESH GENERATION→STRETCH menu:*stretch_nodes

MESH GENERATION→AUTOMESH menu:*overlay_mesh*trim_mesh

MESH GENERATION→SUBDIVIDE menu:*subdivide_elements*subdivide_curves


2. On the rare occasion that a contact body has both elements and curves or surfaces, *identify_contact will now only identify the elements of the body if the body is deformable, workpiece, heat_rigid, or acoustic and the curves or surfaces if the body is rigid or symmetry. Previously, it would identify both.

3. Boundary conditions and initial conditions that are applied to geometric entities are now by default drawn on the geometric entities instead of on the attached mesh entities as before. Two new commands:

*draw_applys_on_mesh on|off*draw_iconds_on_mesh on|off

have been added that allow switching back to the old behavior. These commands can be found in the BOUNDARY CONDITIONS menu and the INITIAL CONDITIONS menu, respectively.

4. The command *identify_applys now draws arrows for every boundary condition, regardless of whether *set_applys is on or off. Previously, *identify_applys displayed the legend, but no arrows if *set_applys was off. Similar for initial conditions.

5. MSC.Marc Mentat has been enhanced to be a full 64 bit compliant application for use on SGI Irix 64, Sun Solaris 2.8, Compaq Tru64, HP 11.0 64 bit, IBM AIX 5.1 and Linux 2.4.9. This allows for much larger models to be created and post processed, up to 2 billion nodes.

6. The file specified on the command line to be opened may now include any file type that MSC.Marc Mentat recognizes in addition to the .mfd and .mud files:MSC.Marc Input File (.dat), AutoCad (.dxf), NASTRAN (.bdf, .nas), PATRAN (.pat), C-MOLD (.par), ACIS (.sab, .sat), STL (.stl), Ideas (.unv), VDA-FS (.vda).

Description of the New FunctionalitiesMSC.Marc Mentat Postprocessing Enhancements

66

14. MSC.Marc Mentat Postprocessing Enhancements

A. MPEG and AVI Animation

MSC.Marc Mentat can now create an MPEG animation file or an AVI (Windows NT/2000/XP only) animation file. It is accessed from the RESULTS→ANIMATION submenu. The settings are preset to typical default values so that for most users, only one button needs to be pressed to start the creation of the animation file.

The MPEG and AVI animation menus are very similar. The BASE FILE NAME is automatically set to the name of the post file. The GENERATE ANIMATION FILES button enables or disables the creation of the intermediate display list files that are read and displayed when selecting the PLAY button in the ANIMATION main menu. In most cases, you will want to have this option selected unless you are assembling an animation from various increments in the post file. The buttons under the INCREMENTS section are the same as in the RESULTS main menu. The ATTRIBUTES menu provides shortcuts to the LEGEND settings, RANGE and COLORMAP buttons. The CLEAN FILES button will remove all the intermediate display list files and the PPM image files used to create an MPEG movie. Do not use this button until you have successfully viewed the resulting animation file.

Figure 44: MPEG and AVI Animation Menus

The DELAY button in the MPEG menu will duplicate frames (increment images) in the MPEG movie since some MPEG players will attempt to play the movie in real time. For example, if there are 100 increments, some MPEG players will skip frames to try and play the entire movie in 100/24fps = 4 seconds.

67Description of the New FunctionalitiesMSC.Marc Mentat Postprocessing Enhancements

When the MAKE MPEG MOVIE button is pressed, the intermediate display list files are generated, then they are played back and images are created from each of the increments and stored in the PPM graphic files. Then the MPEG encoding program, mpeg_encode.exe in MSC.Marc Mentat’s bin directory, is run in the background.

Note that there is no feedback from this program back to MSC.Marc Mentat to indicate that the MPEG encoder has completed. The most reliable way to detect this is to use the ps command on Unix or the Windows Task Manager on Windows NT. You can also monitor the size of the MPEG file: when it is no longer growing in size the encoder has completed generating the file.

The COMPRESSION DIALOG button in the AVI menu allows you to select the compression method for the AVI file. In most cases, you will NOT want to select the default of Full Frames (Uncompressed). You should select Microsoft Video 1 as the compression method.

When the MAKE AVI MOVIE button is selected, it performs tasks similar to that for the MPEG movie. The intermediate display list files are generated, and then they are played back and images are created. However, these images are not saved to a file. They are fed immediately to the AVI movie generator. When all of the display list files have been displayed and images created, the AVI movie generator will write the AVI file to disk.

B. Post Procedure File

New commands have been added named *set_post_procedure on/off (menu button POST PROCEDURE) and its associated command *post_procedure_file <procedure filename> (menu button FILE) in the RESULTS menu. These commands allow for the specification of a procedure file whose contents will be executed as each increment is read. This is most useful when a 2-D analysis has been run and a 3-D model is desired to be viewed based on symmetry.

For example, the MSC.Marc User’s Guide, Chapter 10 problem of a tire analysis produces a 2-D section of the tire. To build a full 3-D model, place the following commands in a procedure file and select it using the FILE button:

*clear_mesh*set_expand_rotations20 0 0*set_expand_repetitions18*symmetry_elementsall_existing*expand_elementsall_existing

Description of the New FunctionalitiesMSC.Marc Mentat Postprocessing Enhancements

68

To enable its use, select the POST PROCEDURE button.

See the figures below of the original analysis on the left, and the full 3-D model is on the right.

C. Merge Contact Model Files

A new command *post_merge_bbc has been added that automatically merges the formatted MSC.Marc Mentat model file containing the beam-to-beam contact location points for the current increment with the current postprocessing model, if that file exists. Similarly, the new command *post_merge_spline automatically merges the formatted model file containing the analytical description of deformable contact bodies for a given increment with the current postprocessing model, if that file exists.

These files are created by MSC.Marc during a contact analysis if the appropriate flags have been switched on during preprocessing. The flags can be found in the JOB RESULTS→CONTACT MODEL FILES menu and the new commands can be found in the POST PROCESSING RESULTS→TOOLS menu.

Both commands can be used in combination with the new *post_procedure_file facility (see item 2, above) to automatically merge the appropriate model file when an increment is read from the post file. Note that in such a procedure file, the *clear_geometry command should be called prior to one of these commands to remove any points, curves, and surfaces that were merged for a previous increment.

D. Generalized XY-Plot

Several enhancements have been made to the XY-plotter. The legend of the plot is now switched on by default. The names of the curves, as displayed in the legend, are by default derived from the legend and the names of the x- and y-axes of the original plot from which they were copied. New commands have been added to change the curve name (*set_xy_plot_curve_name) and to set the title of the plot (*set_xy_plot_title) and the names of the x- and y-axes (*set_xy_plot_xname and *set_xy_plot_yname, respectively).Finally, the XY-plotter now draws multiple curves using the same colors and symbol sequence as the history and path plots.

69Examples of New FunctionalityNew Functionalities

III. Examples of New Functionality

New Functionalities

1. Analysis Performance Improvements

New Features Guide (NFG): Chapter 16

2. Contact Enhancements

Contact with Quadratic Elements: e8x75a, e8x75b, NFG: Chapters 1 and 10

Thermal Contact: e8x76a, e8x76b, e8x76c, NFG: Chapter 3

Beam Contact: e8x83, NFG: Chapter 2

3. Electrical/Electronics

Piezoelectricity: e8x73, e8x74a, e8x74b, NFG: Chapter 14

Electrical-Thermal-Structural Analysis: e5x19, NFG: Chapter 15

4. Element Technology

Thick, Reduced Integration Shell Element: e4x17, e4x18, e8x71, e8x72, NFG: Chapter 9

Heat Transfer Composite Elements: e5x5c e5x6b

New Rebar Elements: e2x37c, e8x67a, NFG: Chapter 7

Cavity Elements: e4x16a, e4x16b, e4x16c, e4x16d, NFG: Chapter 8

5. Material Models

Anisotropic Plasticity (Hill’s and Barlat): e8x38e, e8x38f, e8x70, NFG: Chapter 9

Shape Memory Alloys: e8x80a, e8x80b, e8x81a, e8x81b, e8x82a, e8x82b, e8x82c, NFG: Chapter 12

Gasket Material for Heat Transfer and Coupled Analysis: e3x39c, e3x39d, NFG: Chapter 10

Implicit Creep: e3x29b, NFG: Chapter 17

Chaboche Model: e3x40, NFG: Chapter 11

6. Automatic Time Stepping Scheme (AUTO STEP)

Creep: e3x12b (manual criterion), e3x12c (automatic criterion), e3x22f (in lieu of analysis using AUTO CREEP), NFG: Chapter 18

Thermal: e3x22b (in lieu of analysis using TRANSIENT), e3x22c (in lieu of analysis using AUTO THERM)

Dynamics: e6x13c, e8x66b

New State Variable Criterion: e8x45b

7. Steady State Rolling of Tires

Tires: e8x67, NFG: Chapter 7

Examples of New FunctionalityNew Functionalities

70

8. Constraints

Nonlinear Springs: e8x52, NFG: Chapter 9

RBE2/RBE3 (MPCs compatible with MSC.Nastran Input): e2x80, NFG: Chapter 13

INSERT option: e2x14c, e2x37c, e8x67b, NFG: Chapter 7

9. Remeshing/Rezoning

Rubber Seal Pressing: e8x77

Double-sided Contact: e8x78

Hot Pressing of a Block: e8x79

NFG: Chapters 5 and 6

10. Metal Cutting

NC Machining Analysis: e8x85, NFG: Chapter 4

11. Miscellaneous

Forming Limit Diagrams: e8x38g, e8x72a, NFG: Chapter 9

71List of Defects Fixed in this ReleaseMSC.Marc 2003

IV. List of Defects Fixed in this Release

MSC.Marc 2003

Adaptive Mesh Refinement:

Contact:

Coupled Analysis:

1 Manual remeshing has been fixed to give correct results for tetrahedral elements.

2 CONTACT CHANGE, GEOMETRY CHANGE, and ISOTROPIC CHANGE options have been fixed to give correct results in rezoning.

3 The use of distortion criterion has been fixed for automated remeshing with multiple bodies.

4 Adaptive meshing has been fixed to give correct results for tetrahedral elements.

5 DEACTIVATE option has been fixed to give correct results with adaptive meshing.

6 The convergence testing on displacements in the step after remeshing in the automated remeshing and rezoning has been fixed.

7 Shell elements now give correct results in coupled analysis when adaptivity is used.

8 wkslp.f and crplaw.f are now correctly called for analyses with global remeshing.

1 A node with a fixed displacement coming into contact with a flexible patch from which the patch normal is not exactly perpendicular to the fixed displacement could get some small displacement in the direction of the fixed displacement. This defect has been fixed.

2 In the usage of motion.f and defining velocities of the die as a function of time (cptim), the potential problems with the APPROACH option have been fixed.

3 Error in analysis with two load controlled bodies and one velocity controlled body has been fixed.

4 Use of ADAPT GLOBAL now gives correct results with contact in coupled analysis.

5 Iterative penetration checking procedure has been fixed with position controlled bodies.

6 Error for a node with applied displacements and simultaneously in contact with two NURBS has been fixed.

7 Gradual release has been fixed to give correct results.

1 Coupled analysis procedure for anisotropic materials has been fixed.

2 Coupled analysis with UPDATE and TRANSFORMATION options has been fixed.

List of Defects Fixed in this ReleaseMSC.Marc 2003

72

Design Sensitivity and Optimization:

Dynamics:

Element Formulation:

Fluid Analysis:

Fracture Mechanics:

Heat Transfer and Thermal Stress:

1 Element number printout in design sensitivity analysis has been fixed. Analysis was correct though.

1 Dynamic,5 (Fast Central Difference Operator) has been fixed to give correct results in the first increment also in the case of applied loads without follower force.

2 Lanczos and Power sweep now give identical results during buckle increments.

3 Harmonic analysis now gives correct results with elastic foundation.

4 Interfaces to user subroutine usprng.f has been fixed to give correct results in harmonic analysis.

5 Modal superposition with elements 52 and 98 has been fixed.

1 Element type 52 (elastic beam) has been fixed to give correct results with PROCESSOR and POINT LOAD options.

2 Element type 19 (generalized plane strain) has been fixed to give correct results in a finite strain analysis.

1 Fluid Solid analysis has been fixed to give correct results for heat transfer elements defined on last line of connectivity block.

2 film.f is correctly called for fluid-thermal-solid simulation.

3 Fluid Solid analysis has been fixed to allow the use of assumed strain for the solid part of the model.

1 Shift direction calculation for collapsed brick elements in 3-D analysis with J-Integrals has been fixed.

1 Thermal radiation with reflection for fahrenheit has been fixed.

2 RADITION option has been stabilized (for cases where part of the model is connected to the outside world via radiation and not structured elements, films, and boundary conditions.

73List of Defects Fixed in this ReleaseMSC.Marc 2003

Loading and Boundary Conditions:

Material Models:

Memory and I/O Related:

Miscellaneous:

Parallel Processing:

1 Nodal coordinates with CYLINDRICAL option are correctly transformed.

2 INITIAL ACCELERATION option has been fixed to work correctly for AXITO3D analysis.

3 SERVO LINK option has been fixed to read maximum number of retained nodes correctly.

1 The resulting creep tensor has been fixed to be defined correctly when ORIENTATION option is used.

2 Plastic strain energy is now being calculated correctly for steady state, Eulerian R-P Flow.

1 The NEW option has been fixed to be read in the model definition section.

1 User subroutine upstno.f modified to correctly extract nodal data.

2 The .t01 is no longer erroneously deleted at the end of the run.

3 The utility routine elmvar.f has been modified to correctly pass back beam forces and moments.

4 Nodes of the springs are no longer being swapped in the usprng.f user subroutine.

1 Parallel version has been fixed to correctly support for t19 file to input a post file in case of change state (e.g. Thermal-Stress analysis).

2 Parallel analysis is fixed to give correct results with a combination of AUTO THERM and CHANGE STATE.

3 Creep analysis now gives correct results in analysis on multiple processors.

4 AUTO CREEP option has bee fixed to give correct results with use of nonconsecutive element numbers.

List of Defects Fixed in this ReleaseMSC.Marc 2003

74

Preprocessing, Postprocessing, and Output:

Restart:

Solver and Analysis Procedure:

Also, several changes have been made to documentation and data files in the demo directory.

1 Discontinuous post file on restart has been fixed for adaptive meshing.

2 User subroutine elmvar.f has been fixed for post code 269.

3 Post file has been fixed to contain correct results in magnetostatic analysis.

4 Output has been fixed to contain correct values for the maximum and average relative sliding velocity.

5 Output for strain energy has been fixed for APPROACH option.

6 Correct messages are issued in case of residual convergence criterion usage where loads are applied only to free node.

7 Analysis with usage of flow lines option without global remeshing exits correctly with input error message.

8 Strain energy is correctly output for rubber models in total Lagrangian analysis.

9 The beam moments for element type 5 have been made consistent with other beam elements.

1 The restart capability has been fixed when upper bound on the number of elements on the ADAPTIVE option is much larger than the actual number of elements used.

1 AUTO STEP procedure has been fixed for cases with coupled analysis.

2 Case of multiple AUTO STEP options has been fixed.

3 AXITO3D feature fixed to correctly account for point and distributed loads in increment 0.

4 Transient heat transfer has been fixed for powder materials.

5 Solver, 6 has been fixed for use with RESTART and ADAPTIVE MESHING on SGI.

6 For analysis using the in-core, direct profile solver, an automatic switch is made to the out-of-core direct profile solver if the integer value, during the determination of the storage requirements, exceeds the number 2**31.

7 Eigenvalue analysis with greater than 160 Lanczos vectors using HP hardware sparse solver has been fixed.

75List of Defects Fixed in this ReleaseMSC.Marc Mentat 2003


Preprocessing:

1 Element mass and volume are now properly calculated for truss, elastic beam, cable and elbow (general section) elements.

2 The CHECK CROSS command would sometimes not detect crossed elements if they were neighbors. This has been corrected.

3 Restart runs are now handled properly when running a DDM job.

4 The geomdist_surfaces command would sometimes cause MSC.Marc Mentat to hang due to a tolerance error. This has been corrected.

5 If the coordinates of a point are changed using the EDIT POINT (*edit_points) or the MOVE POINT (*move_points) command and the point is part of a curve (surface), the coordinates of the nodes attached to that curve (surface) are now properly updated.

6 The label VELOCITY in the VELOCITY CONTROL popup menu for rigid contact bodies did not clearly indicate that translating a rigid body means that the center of rotation is translating too. It has been renamed VELOCITY (CENTER OF ROTATION).

7 Small gaps between curves would sometimes cause MSC.Marc Mentat to hang when cleaning surface loops. This has been fixed.

8 Links are no longer renamed when the renumber_all command is run.

9 Model files with Hypermesh layers are now read correctly on Linux.

10 When Fixed stepping procedure in Dynamic Transient (Loadcases) is selected, the Automatic time step cut back button is now invisible.

11 When using design variables, the composite thickness is now properly displayed in the EDIT menu.

12 Saving an image on Windows NT no longer causes a crash when the pathname is longer than 100 characters. The limit now is 256 characters.

13 The procedure file for MSC.Marc User’s Guide, Chapter 16 example c16a.proc has been corrected to use the command *loadcase_option converge:displacements.

14 The MSC.Marc User’s Guide, Chapter 23 model file has been properly renamed to ch23.mfd.

15 MSC.Marc Mentat now handles spaces in path names properly.

16 A sweep operation is no longer performed when changing element class using the new change_element_class command.

17 Viewfactor calculations are now identical on different platforms.

18 Boundary conditions on curves are now correctly transferred to nodes.

List of Defects Fixed in this ReleaseMSC.Marc Mentat 2003

76

Postprocessing

MSC.Marc Input File Writer

19 The geometric property option THICKNESS DIRECTION (comp_cont_thickdir) for COMPOSITE/GASKET elements is now saved to the model file.

20 Subdividing a curve using a bias factor is now correct for all values of the bias factor within the valid range

21 The numerical function surface_point_id (SURFACE,I,J) has been fixed. The I and J were interchanged.

1 When the POST DELTA option is used, the range is now properly calculated to display the results.

2 The label of post code 461 has been corrected to read "Elastic Strain in Preferred Sys". In the previous versions it was "Total Strain in Preferred Sys".

3 Springs in postfiles that have multiple domains are now properly read.

4 Vectors are now plotted properly on Linux platforms.

5 The integration point value at collapsed nodes of a collapsed element in path plot and history plot is now correctly displayed.

6 Certain conditions might cause the program to hang when plotting iso-surfaces. This has been fixed.

7 When a history or path plot is generated and then the data is transferred using COPY DATA TO CLIPBOARD, the titles on the data now do not contain the magnification factor that appears on the plot (x10...).

8 Several memory leaks have been removed.

9 Post processing of files over 2GB has been corrected on HP, IBM, SUN, provided that the file system supports files over 2GB. The only platforms that do not support 2GB post files are Windows NT and Linux.

1 The thermal contact data is now written correctly in a coupled fluid-thermal-solid analysis.

2 The ambient temperature for film boundary conditions are now written properly.

3 A correct input file is now written for a model with a CREEP loadcase using the MULTI-CRITERIA stepping procedure, if the AUTOMATIC TIME STEP CUT BACK feature is activated.

4 If a model contains an edge source, face source, or volume source boundary condition used in a harmonic loadcase of an acoustic-solid job, a correct MSC.Marc input file will now be produced.

77List of Defects Fixed in this ReleaseMSC.Marc Mentat 2003

MSC.Marc Input File Reader

5 If a model contains an actuator element with a time-varying length, and if the relative length change per time step is smaller than 1e-4, a correct input file will now be created.

6 The limit of 9 rigid regions for the LORENZI option is handled correctly for the geometry search method and the manual method.

7 If a model contains a non-uniform volume flux on an element of type 37 or 38, a correct input file will now be created.

8 If a model contains elements with a material using the Johnson-Cook model for plasticity, an correct input file will now be created.

1 The last value of the temperature effects data is now read properly from the input file.

2 When importing a file, sets are now checked to determine if any duplicates exist. The duplicates will be removed after import.

3 Upon importing a file in which a nonsymmetric solver is requested, the NONSYMMETRIC SOLUTION option (*job_option solver_nonsym) is now switched on properly. In addition, the SOLVER TYPE (*job_option solver) is set correctly.

4 A MSC.Marc input file containing point flux is now handled properly.

5 The rebar layer orientation type is now correctly imported from the geometry option.

6 The adaptive data is now properly read.

7 The udump model definition option data is now handled correctly.

8 The MSC.Marc input reader will now properly handle the CYLINDRICAL model definition option when the nodes are not numbered consecutively.

9 The utransform model definition option data is now handled correctly.

10 The Mohr-Coulomb alpha coefficient is now stored properly.

11 The data on quadratic behavior through the thickness of an element is now read properly.

12 Viewfactors are now supported.

13 The contact data in demo problems e8x19.dat, e8x35.dat, e8x60.dat,... is now read properly.

14 The response spectrum table in demo problems e6x6a.dat and e6x6b.dat is now read correctly.

15 The reading of axito3d is now read correctly in demo problems e8x61b.dat and e8x67b.dat.

16 The B-H data is for demo problem e8x24b.dat is now read properly.

List of Defects Fixed in this ReleaseMSC.Marc Mentat 2003

78

I-DEAS Reader

MSC.Nastran Reader

MSC.Marc Python

17 The damping parapmeters are now read properly.

18 Adaptive meshing parameters are now read correctly.

19 Electrical contact properties are now read correctly for coupled Joule input.

1 The Ideas translator now uses a relative tolerance to check for duplicate boundary and initial conditions. Previously it used a fixed tolerance.

2 The Ideas translator can now read the thickness of a shell element.

1 Reading in a MSC.Nastran input file where elements have a varying thickness at the nodal points now properly assigns them to the elements.

2 The MSC.Nastran reader now handles the case When importing a MSC.Nastran file where the shells have the id numbers 1, 2, and 3 and the beam-id numbers are identical, i.e. 1, 2, and 3.

3 Nodal temperatures as mechanical boundary conditions in a patran neutral file or a nastran bdf-file are now properly read in as mechanical boundary conditions instead of thermal boundary conditions.

4 The MSC.Nastran translator now properly handles the PBAR card.

5 The material property orientation angle, as specified on the 8th field of the is now properly interpreted as the angle between the first the direction of the material coordinate system of the element and the first edge of the element.

6 A MSC.Nastran input deck with MPC card is now handled properly.

7 Element types are now assigned during import.

8 The X and Y axis for PBEAM, PBAR, PBCOMP are now translated correctly.

9 The PBEAML and PBARL are now translated properly as an elastic beam.

1 The extrapolation method in the Py_Post module has been fixed to properly set the extrapolation method. The current extrapolation method may be checked by using the extrapolate member.

79List of Known Problems in this ReleaseMSC.Marc 2003

V. List of Known Problems in this Release

MSC.Marc 2003

1. The new table style input is not released efficiently. However, the capability is available in the product along with documentation and may be used in specific situations (e.g. nonlinear load application curve where the alternative is to break up the curve into several linear segments). There are several limitations to this capability:

New Table Input Restrictions

(1) Tables of time are not supported with Auto Increment, use Auto Step instead.

(2) Table input is not available with Fourier Analysis.

(3) Table input is not available with Pressure Cavity Loading.

(4) The definition of the table cannot change upon restart.

(5) Use of user subroutine for film option requires new user subroutine UFILM as opposed to FILM, this is not documented in MSC.Marc Volume D: User Subroutines and Special Routines.

(6) Table input is not supported with element types 95 and 96.

(7) Table input does not support edge loads on shells.

2. The true quadratic contact, the post file quantity contact normal stress is available only at the contacting nodes.

3. True quadratic contact cannot be used in a coupled structural-acoustic analysis.

4. In 3-D, true quadratic contact should preferably not be used together with:

– stick-slip friction

– shell element 22.

5. The following problems currently exist with the beam-to-beam contact:

– if there is contact between beam elements and nodes of these beam elements are also contacting solid or shell elements, the friction due to contact of solid or shell elements is not correct

– it does not allow branches

– not supported with DDM.

6. The thickness of beam elements is currently ignored if (the nodes of) beam elements touch a rigid surface, a shell element, or a face of a solid element.

7. Steady state rolling contact model does not support

– high-order 3-D elements

– DDM.

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8. For Tet remeshing:

– self-contact with remeshing may show unwarranted penetrations.

9. INSERT option does not support

– local or global remeshing

– DDM (parallel jobs).

10. Mass lumping should not be done for element types 52 and 98 in explicit dynamic analysis using DYNAMIC,5 parameter.

11. AXITO3D option does not support kinematic hardening of plasticity and creep. No back stress and/or creep strain are available in the post file.

12. Parallel jobs (DDM) on Windows NT have a memory limit of 1 GB per domain. This limit is 2 GB per domain for Windows 2000 and Windows XP.

13. Convergence of steady state rolling analysis using torque control is slower than when using spinning velocity control. It is useful to start with spinning velocity controlled solution and use torque control when the solution is close to the final one.

14. Environment variables for parallel jobs (DDM) on the Windows platform must be set using the System applet from the Control Panel. This means that if the variable MSC_LICENSE_FILE is to be set to point to a different license file, it cannot be changed by modifying the include.bat script or by setting in in your command prompt window.

81List of Known Problems in this ReleaseMSC.Marc Mentat 2003


1. MSC.Marc import does not support element types 4, 8, 13, 15, 16, 17, and 24

Element types 4, 8, 13, 15, 16, 17, and 24 are not supported by the MSC.Marc reader (IMPORT MARC).

2. Running MSC.Marc Job in Different Directory

When the file browser is used to open a model file, a MSC.Marc job is always run in the directory containing the model file. See Item 2 under X. Important Notes.

3. Drawing of symbols on Digital Unix very slow

The drawing of symbols (nodes, points, etc.) in the OpenGL version of MSC.Marc Mentat on Compaq/Digital Unix is very slow. This is due to a problem in the glBitmap implementation. This problem is seen when a model is first drawn with nodes or points turned on.

4. MSC.Marc import and export does not support edge foundation on 3-D beam elements

For 3-D beam elements, the edge foundation option (BOUNDARY CONDITIONS→ MECHANICAL→EDGE FOUNDATION) is not supported by the MSC.Marc reader (READ MARC) or MSC.Marc writer (WRITE MARC).

5. Converting quad surface to solid face not supported

Converting a quad surface to a solid face is not supported.

6. Recover option always requests both modal stresses and reactions

When doing an eigenvalue extraction, MSC.Marc Mentat always generates the RECOVER option to request both modal stresses and reactions. This can lead to slow eigenvalue analysis if these items are not needed. To disable this, specify a 0 in the 3rd field (columns 11 – 15) of the second data block of the RECOVER option if only the eigenvectors are required.

7. Contact Status may show non-integer values in Local Adaptivity analysis

When postprocessing the scalar Contact Status in a Local Adaptivity analysis, some nodes may appear in red (a value of .5) when they should have an integer value of 0, so the nodes with a value of 0.5 are not in contact.

8. 3-D Beam Results Layer Selection not written to dat file

When results are requested for ALL or OUTER & MIDPLANE layers of 3-D beam elements (under JOB RESULTS), this information is not written to the .dat file. Only layer 1 is written to the .dat file post section.

9. Thickness option not supported for Bearing Analysis

The options THICKNESS and THICKNS CHANGE for bearing analysis are not supported.

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10. Scaling a Solid Cylinder fails on HPUX

The MOVE→SOLIDS command will not scale a solid on HP-UX 10.20. This is due to a problem in the ACIS library that MSC.Marc Mentat uses for solid modeling.

11. Converting Solid Faces to Surfaces

Running the SOLID FACES TO SURFACES command under the SOLIDS menu will fail if there are any inside out faces. If the command fails, the solid should first be checked with CHECK ENTITIES before running this command. Run the CHECK ENTITIES command, and if any error is found, do not run the SOLID FACES TO SURFACES command.

12. Converting a Solid Cylinder to Faces

When a solid cylinder is converted to a surface using the SOLID FACES TO SURFACES command and then converted to elements using the SURFACES TO ELEMENTS command, the resulting elements will overlap at the surface boundary.

13. MSC.Marc Python feature availability

The external modules py_mentat and py_post are not available for IBM AIX.

14. MSC.Marc Mentat OpenGL version on IBM

The OpenGL version of MSC.Marc Mentat may not operate properly on some IBM platforms. The runtime libraries patch 4.3.3.25 is required.

15. Linux Platforms

The Solids version of MSC.Marc Mentat is not supported on the 32-bit Linux platforms for this release. MesaGL v3.4 or higher is required to run the OpenGL version on Linux.

16. Solids

None of the 64-bit MSC.Marc Mentat executables have Solids (ACIS) capabilities.Also, the Solids version of MSC.Marc Mentat is not supported on the 32-bit Linux and 32-bit IBM.

17. Shell Expand for Line Elements

If the element orientation of 2 connected elements is not the same (e.q. Connectivity of element 1: 1 2, of element 2: 3 2) the shell expand for line elements gives wrong quad elements.

18. Surface Lines in Solid Mode Disappear after MAKE VISIBLE

Surface lines in solid mode will disappear after doing a MAKE VISIBLE (*visible_selected) command. You will need to do a REGEN to see the surface lines.

19. Fill View is Incorrect when not all Table Points are Visible

If a table is created and then the XMIN, XMAX, YMIN, or YMAX value is specified such that not all of the data points will be visible, then when a FILL (*fill_view) command is specified the result will be incorrect.

83List of Known Problems in this ReleaseMSC.Marc Mentat 2003

20. Models with large element id’s may not post process correctly

If a model has element id’s which a very large and some are very small, MSC.Marc Mentat will not post process the post file correctly. For example, if some element numbers are in the 100’s and others are in the 75,000,000’s, MSC.Marc Mentat will not handle this case properly.

21. Translators for 64-bit MSC.Marc Mentat

The translators iges, dxf/dwg, and vdafs are not available in 64-bit mode for MSC.Marc Mentat. They are the 32-bit builds of the translators.

22. Saved view cannot be loaded on SUN Solaris and HP OpenGL version

When a view is saved (SAVE VIEW) from the VIEW menu, it won’t be read properly when using LOAD VIEW on the SUN Solaris and HP platforms with the OpenGL version.

23. OpenGL version with SGI V6 Graphics

The graphics do not always get properly updated when running the OpenGL version on an SGI with V6 graphics, and occasional crashes are found to occur. The only known workaround is to use the X version.

24. SIZE in SCAN menu not correct in DDM analysis with remeshing

The SIZE values shown in the RESULTS→SCAN menu will not be correct for a DDM (parallel) analysis when adaptive meshing is used. The values shown will always be those of the current increment.

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VI. Troubleshooting Tips

1. Contact

i. If a previously running problem fails, check if there are hard-wired values (see Note below) for contact parameters (e.g., contact zone tolerance, separation force etc.). In such cases, the defaults may work better.Note: Under certain conditions, hardwiring of CONTACT parameters may be necessary to model certain physics but if it is done solely for the purpose of making a job run then one could try switching it to default values.

ii. In case convergence is difficult to achieve, discarding initial stress stiffness (through CONTROL option) matrix in elastomer analysis may help. Similarly, taking only the tensile part of the stiffness in shell analysis involving high compressive stresses also can help (this should not be done for eigenvalue analysis).

iii. Use a bias of greater than 0.9 for contact problems (this is especially true for problems involving friction where a bias of 0.99 works best). The default for the bias factor would change in the next release.

iv. When a problem does not converge well with friction, it is advisable to first ensure that the problem is running well without friction to rule out model set up problems. Also, the relative sliding velocity parameter for the Coulomb friction model should not be too tight as it can cause numerical problems. The latter value can be increased and its adequacy can be checking by postprocessing the associated friction forces.

v. Finally, on many occasions the corresponding Rolling Friction models give improved results. The main difference between the models "for rolling" and without rolling is that the "for rolling" model use an improved estimate of the friction condition at the first cycle of an increment. The "for rolling" models are therefore recommended over the ones without "rolling" (in particular for cases of contact where the rigid bodies move).

The extension "for rolling" has historical significance in that the improvements to the model were done initially for ring rolling simulations. However, improved accuracy and convergence of the results is also seen for sheet metal forming and elastomer applications demonstrating the applicability of the model to other types of simulations as well."

vi. In a 2-D contact analysis, the default limit angle between adjacent segments of a contact body is 8.625 degrees, which may play a role if curved structures are modeled using relatively coarse mesh or patches. If there is a significant amount of sliding such that nodes slide from one segment to another, this angle value may cause the nodes to be temporarily stuck at the intersection of two adjacent segments. Sliding to a next segment takes place after separating from the first, which can result in more iterations (or sometimes even non-convergence) compared to smooth sliding. If this happens, increasing the default value of this angle (e.g. to 20 degrees or higher) may speed up the analysis.

85Troubleshooting TipsMSC.Marc Mentat 2003

Occasionally, similar problem may happen for 3-D analysis and the angle should then be increased to higher than the default value of 20 degrees

vii. When the default separation force/stress is used in a contact problem, and the separation behavior is not as expected, one should carefully review the solution to understand the reason. Since the default separation force is set to the maximum residual force in each iteration, nodes not separating could be because the maximum residuals are rather large in the solution. In this case, either specifying a smaller separation threshold or allowing the residuals to become smaller through a tighter convergence tolerance could help. On the flip side, too many nodes separating due to extremely small residuals could also be avoided by providing a larger separation threshold.

viii. Several improvements have been made in penetration and separation checking for the iterative penetration scheme. The new iterative penetration checking scheme is now the default.Occasionally, contact problems working in the previous version of MSC.Marc or newly created problems using the iterative penetration checking can fail earlier than expected. In such cases, if various tips as suggested in i) to vii) above do not prove to be helpful, then insert feature,602 in the parameter section (i.e. before the "end" in the input file) and rerun the analysis.Note: The cases for which feature,602 shows a better performance must be sent to [email protected] for further investigation by the development staff. The parameter feature,602 is undocumented. It activates the old iterative penetration scheme in MSC.Marc 2001. This as well as the increment splitting scheme would be unsupported in the next release, MSC.Marc 2004.

ix. When a load controlled rigid body is used in an analysis, it can be specified with one control node (controlling translational motions only, with no rotations allowed), or with two control nodes (one controlling the translational motions and the other controlling the rotational motions). Note that when the load controlled rigid body is in contact with one or more deformable bodies, sufficient constraints (nodal boundary conditions or springs or gluing) should be provided to the system of bodies such that the load controlled body is free from rigid body translations and rotations. Without proper constraints, the analysis will terminate prematurely with exit 2004 due to singular equations. Also note that degrees of freedom for rotational nodes in the GUI / input deck should correspond to DOF 1 (in 2-D) and DOF 1, 2, and 3 (in 3-D).

x. APPROACH, SYNCHRONIZE options must be used cautiously in conjunction with position controlled rigid bodies. When the position of the body is specified by the user and this position is abruptly modified during the APPROACH loadcase, the body could revert back to the position specified by the user after the APPROACH loadcase. The typical work-around is to use velocity controlled bodies.

xi. A useful aid for trouble-shooting contact problems is use PRINT,5 parameter in the input deck (in MSC.Marc Mentat, it can be activated by JOBS →MECHANICAL →JOB RESULTS→OUTPUT FILE→CONTACT). This provides contact related information about nodes touching, nodes separating, nodes moving from one patch to another, etc. in the output file.


86

2. Load Stepping

i. Since temperature boundary conditions in heat transfer or thermally coupled analysis are applied instantaneously, it may be sometimes difficult to satisfy the tolerance for allowable temperature change for adaptive stepping procedures like TRANSIENT and AUTO STEP. This can be solved by either increasing the tolerance for allowable temperature change, or by using a fixed stepping procedure like TRANSIENT NON AUTO to ramp the applied temperature.

ii. For dynamics problems using the Newmark-Beta or Single-Step Houbolt operators, AUTO STEP checks on the time integration errors and suitably cuts the time step. For high frequency problems or problems with a lot of numerical noise (for e.g., chattering nodes in contact analysis), these cutbacks could cause the time step to be too small. In this case, the feature for checking on time integration errors can be turned off by setting the 3rd field of the 3rd data block of AUTO STEP option in the input file to 1 or by setting the "TREAT CRITERIA AS" TARGETS under the LOADCASES→ MECHANICAL→STATIC→ ADAPTIVE MULTI-CRITERIA (PARAMETERS)→AUTOMATIC CRITERIA menu in MSC.Marc Mentat).

iii. If the CHANGE STATE option using a thermal post file does not seem to work properly in conjunction with AUTO STEP, make sure that the transient time in the thermal post file matches or is larger than that used for the mechanical analysis.

iv. When AUTO STEP procedure is used for adaptive load stepping and the analysis does not seem to be increasing the time step sufficiently even though convergence seems to be okay, the desired number of recycles could be increased from the default value of 3 to a higher value, e.g. 5. This is particularly useful for problems with displacement checking, where a minimum of 2 recycles is already used to establish convergence.

3. Materials

i. When tables are used to specify variations in material properties (e.g., Young’s modulus, yield stress, etc.) with analysis variables (e.g. temperatures and equivalent plastic strains, engineering strains), the data should be provided over the entire range of analysis variables expected to be encountered in the analysis. Failure to do so can cause the material data to be extrapolated to non-physical values resulting in analysis failures (this is very often seen with elements turning inside out or node incorrectly projected on or sliding off the contact surface message).

ii. When the coefficient of thermal expansion is specified as a function of temperature, the instantaneous coefficient of thermal expansion needs to be specified (refer to Chapter 6 of Volume A: Theory and User Information for more explanations).

iii. When rapid changes in elastic strains are encountered in an implicit creep analysis due to changes in loading, bending, or other non steady-state conditions, there is a chance that, in conjunction with the secant tangent scheme, the analysis may encounter a nonpositive definite system of equations in cycle 1 of the mechanical pass. This is usually related to the fact that a large inelastic strain increment was predicted by a default steady state creep formulation used in cycle 0 of the increment. This can usually be solved by either of the following workarounds:


a. flag a nonpositive-definite solution. This usually allows the solution to proceed without impacting the super linear convergence characteristics of the scheme

b. change the flag for the tangent scheme to 3 instead of 1 on the CREEP parameter card. This undocumented flag deactivates the steady-state creep predictor in cycle 0. While this avoids the non-positive definite system, it could impact the convergence characteristics of the solution.

4. Remeshing

i. If 3-D tet remeshing fails, check for:

a. self contact – this can cause the mesher to fail. This is a current limitation.

b. sharp angles in rigid body – the sharp angle can penetrate deformable body in such a great amount that the new mesh’s nodes or elements may be created inside the rigid body. Try to avoid sharp angle or use small elements in those areas, say, using the curvature control to place smaller elements in those area.

c. very thin section and large penetration – this can also cause mesher failure as projection of new nodes to the contact surfaces becomes difficult.

d. deformable-to-deformable contact – try to use different mesh size for each contacting bodies such the lower numbered contact body has a denser mesh.

ii. If there are questionable results:

a. then avoid unnecessary remeshing – as remeshing needs to map data from old mesh to new mesh where there is a big change in element size.

b. due to data mapping, the results in the remeshing increment may show some discontinuity. This is normal.

iii. Selection of appropriate meshers:

a. In 2-D remeshing, do not use overlay mesher if there is self contact or if there is a hole inside the deformable body. Use advancing front mesher in such situations.

b. Triangular mesher can be useful if the geometry of the deformable body has or will have a sharp corner and cannot be meshed properly by using the quad. or degenerated quadrilateral elements. The tape peeling userguide example shows the capability of using the triangle remeshing. However, appropriate element type must be chosen if the problem has large deformation.

5. Restart

i. If a restart analysis does not seem to be applying the applied boundary condition history correctly, you need to make sure that the boundary condition history has been suitably modified to account for the fact that a portion of the analysis has already been completed. There are two ways to accomplish this:

a. shift the X axis of tables in the GUI and write out the portion that remains to be analyzed


88

b. copy the original input file to a new location, set up the RESTART option and then delete the portion of the analysis that is already completed.

ii. If a restart analysis produces Exit 77 though nothing significant seems to have been changed, try inserting the REAUTO option just below the RESTART card and 0,0,1 in the following data card. In MSC.Marc Mentat, this can also be flagged by using the IMMEDIATE option under the JOBS→MECHANICAL→JOB PARAMETERS→ RESTART→COMPLETION OF UNFINISHED LOADCASE menu.

6. Memory Issues in Large Problems

i. To run large problems that address over 2 GB of RAM, you will need the 64-bit version of MSC.Marc running on a 64-bit operating system. To run problems that require more than 8 GB of RAM, consider the following.

There is a 8 GB limit on memory in MSC.Marc. However, this is a limit on some operations within the program and not the total model size. Assuming you have more than 8 GB of physical RAM available, you can run jobs that require more than 8 GB of RAM by trying the following in the order given:

a. If it is a parallel analysis, then decompose the model into domains such that each domain is smaller than 8 GB.

b. Use ELSTO in the parameters section. This writes element quantities to disk. You will need ample free disk space.

c. If there are no Lagrange multipliers (gap or Herrmann elements) or use of structural elements (beams or shells) then switching from a direct sparse solver to an iterative sparse solver would help tremendously both in terms of memory and speed.

d. Use solver 2, preconditioner 3 (i.e. the diagonal preconditioner). Since this solver uses less memory, the amount of memory required may decrease to less than 8 Gbyte. However, this will decrease the computational efficiency as well

e. Try solver 8 with optimization type 11. That is, the Multifrontal Sparse solver with METIS bandwidth optimization 11 and is now a default in MSC.Marc Mentat.

f. On 64-bit SGI machines, try solver 6, the hardware sparse solver.

In addition, even though the hardware may have adequate memory, the operating system may have to be re-configured to allow large amounts of memory to be used. On some systems, user limits also may have to be adjusted (e.g. ulimit command on many systems will allow larger data size). Please check with your systems personnel if unfamiliar or unable to check the above.

Finally, make sure MSC.Marc is configured to allow a full 8 GB of memory allocation. This can be verified by looking at the value of MAXSIZE at the end of the include file. The include file is in the tools directory. MAXSIZE should be set equal to 2000.

ii. To pre- or postprocess more than 2 Gbyte of data in MSC.Marc Mentat, the 64-bit version needs to be used on a 64-bit operating system. If the 32-bit version of MSC.Marc Mentat is used, the post file can be larger than 2 Gbyte on systems where


large file support is available; however, the amount of data in each post-increment must be less than 2 Gbyte.

iii. The SIZING parameter specifies how much memory MSC.Marc should allocate initially. If the sizing card specified is too small, MSC.Marc will automatically reallocate memory. For most problems, you will not have to adjust the card. Simply let MSC.Marc reallocate memory.

However, for large problems, the reallocation process can be time consuming as well may fail to get memory if the process tries to get a block of memory but goes out of system limits (note that most systems do not temporarily release the previously allocated memory block till the reallocation process is completed). In such cases, it is more efficient to allocate a large block of memory initially, and let MSC.Marc fill it up as your job progresses.

7. User subroutines

If there are problems in jobs with user subroutines, a variety of approaches are available for troubleshooting:

i. Debug and fine-tune a user subroutine on a small test model before applying it to the actual finite element problem.

ii. Run the user subroutine as a stand-alone program, provide a wide range of inputs to the program and make sure that the outputs are stable numbers.

iii. If division expressions are being used, make sure that the denominator cannot go to zero. Extra precaution may be needed for increment 0 or 1, where many quantities are initialized.

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VII. Web Updates for Bug Fixes

As a part of continued commitment to provide the best service to the users of our products, the web based system will be utilized to provide rapid availability of the updates to the released products.

The revisions containing minor enhancements and bug fixes to the MSC.Marc 2003 release (as well as bug fix list) will be available at:

http://www.marc.com/Support/Technical_Support/updates_and_utilities.htm

The announcement for web update would be made on the MSC.Marc home page as well as MSC support page. Appropriate links to this site in the MSC.Marc home page and MSC support page are also available for navigational convenience. The updates to existing MSC.Marc product will be available on ‘as needed’ basis (please check the MSC.Marc homepage or URL above for new updates).

Please click on the “readme.txt” before proceeding with the download. The downloaded archives will require passwords to decrypt them. These passwords can be obtained from your local support personnel.

Both full libraries/binaries as well as incremental updates (considerably smaller size and good for download via a slow speed internet connection) would be provided. Please note that for the incremental updates, only the updates beyond MSC.Marc 2003 (i.e. revision versions of MSC.Marc 2003) are available on the web and the original release MSC.Marc 2003 must be installed on the machine. The install script when executed will update the version but will also save the original MSC.Marc 2003.

91List of Build and Supported PlatformsMSC.Marc 2003

VIII. List of Build and Supported Platforms

MSC.Marc 2003

Note: For most platforms, the default MPI setting for this release uses MPICH, with the option of switching to hardware specific MPI when so desired. The exceptions are for the following platforms:

IBM AIX 4.3.2 RS/6000 and Linux 2.4.16, where only MPICH MPI is available.

IBM AIX 4.3.2 RS/6000 SP, IBM AIX 5.1 (64-bit), and HPUX 11.0 (64-bit), where only hardware MPI is available.

Vendor OS HardwareFORTRAN

VersionParallelEnabled

DefaultMPI

AlsoWorks On

HP-Compaq (DEC)2 OSF1 4.0d2 Alpha2 f77 5.12 yes2 MPICH 1 TRU642

HP (32-bit)HP (32-bit)HP (64-bit)2

HP (64-bit)2

HPUX 10.20HPUX 11.0HPUX 11.0HPUX 11.22

PA2.0PA2.0PA2.0Itanium 2

f77 B10.20.16f90 2.4f90 2.4f90 2.6.2

yesyesyesyes

MPICH 1

MPICH 1

HP MPI 1.06HP MPI 1.08

IBM (32-bit)IBM (32-bit)IBM (64-bit)2

AIX 4.3.2AIX 4.3.2AIX 5.1

RS/6000RS/6000 SPRS/6000

XLF 5.1.1XLF 5.1.1XLF 8.1.0

yesyesyes3

MPICHIBM POE 3.1

AIX 4.3.3 or later

SGI (mips3 32-bit)SGI (mips4 64-bit)2

IRIX 6.2IRIX 6.2

R8000/R10000R8000/R10000

f77 7.2.1f77 7.2.1

yesyes

MPICH 1

MPICH 1IRIX 6.3, 6.5IRIX 6.4, 6.5

Sun (32-bit)Sun (64-bit)2

Solaris 2.6Solaris 2.8

Ultra2UltraSparc3

f77 4.2f90 7.0

yesyes

MPICH 1

MPICH 1Solaris 2.7, 2.8Solaris 2.8 or later

Linux (32-bit)Linux (32-bit, myrinet)2

Linux (64 bit)2

Linux 2.2.12Linux 2.4.16Linux 2.4.18

Intel Pentium or equiv.Intel Pentium or equiv.Itanium 2

pgf77 3.1-3pgf90 4.0-2Intel 7.0

yesyesyes

MPICHMPICH4

MPICH

Linux 2.2.12 or laterLinux 2.4.16 or laterLinux 2.4.18 or later

Intel NT 4.0 sp3 Intel Pentium or equiv. Compaq Visual Fortran 6.0a

yes MP-MPICH Windows 2000, XP

1 Hardware MPI version also available (via maintain in /tools directory).2 Support large files (> 2 GB).3The default is a serial build. It can be switched to use hardware mpi if available.4The myrinet build requires version 1.5.1 of the gm drivers.

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The following platforms and operating systems are supported by MSC.Marc Mentat 2003.

Vendor OS Hardware Also Works On OpenGL1

HP-Compaq (DEC)HP-Compaq (DEC)

OSF1 4.0DOSF1 5.1D

AlphaAlpha

TRU64TRU64

yy

HP (32-bit)HP (64-bit)HP (64-bit)

HPUX 10.20 (32 bit)HPUX 11.0 (64 bit)HPUX 11.22 (64 bit)

PA2.0PA2.0IA64

HPUX 11.0 yyy

IBM (32-bit)2

IBM (64-bit)2AIX 4.3.2 (32 bit)AIX 5.1 (64 bit)

RS/6000RS/6000

AIX 4.3.3 or later yy

SGI (mips3 32-bit)SGI (mips4 64-bit)

IRIX 6.2 (32 bit)IRIX64 6.4 (64 bit)

Mips3Mips4

IRIX 6.3–6.5IRIX64 6.4-6.5

yy

Sun (32-bit)Sun (64-bit)

Solaris 2.6 (32 bit)Solaris 2.8 (64 bit)

UltraUltra III

Solaris 2.7–2.8Solaris 2.9

yy

Intel NT 4.0 sp3 Intel Pentium Windows 2000, XP y

Linux (32-bit)2

Linux (64-bit)2Linux 2.2.12Linux 2.4.9

Intel PentiumIntel Itanium

Linux 2.2.13 or laterLinux 2.4.10 or later

yy

1 See OpenGL Compatibility table below.2 The Solids version of MSC.Marc Mentat is not supported in this build.

93List of Build and Supported PlatformsOpenGL Compatibility

OpenGL Compatibility

When running over a network the following combinations of client machine (where MSC.Marc Mentat is running) and graphical server (where the user is viewing the program) have been found to work properly using OpenGL:

Client

Server

Compaq HP1 IBM SGI SUN2 NT3, 4 Linux5

Compaq (DEC) y6 n y n y y n

HP y y y y7 y y y

IBM y y y y y y n

SGI y y y y y y n

SUN y y y y y8 y n

NT n n n n n y n

Linux y y y n9 y y y

1 You must install the “OpenGLRuntime B.10.20.08 HP-UX OpenGL Run Time Environment” (OpenGL 1.1 Revision 1.15).

2 Running “what /usr/openwin/lib/libGL.so” should return a date of 10/27/99 or later.3 Requires additional software (see http://www.hummingbird.com or other vendor of X server

software).4 The following OpenGL graphics cards have been found not to work:

Compaq PowerStorm 300 and 4D10T

STB Velocity 4400

Intense 3D Pro 34105 Requires MesaGL v3.4 or higher.6 Double buffering not available (4.0D version will not work on 5.x and visa versa).7 Some buffering problems may occur when changing workspaces.8 Single (direct) buffering may not work on some Solaris 2.6 machines.9 X version doesn’t work either.

List of Dropped PlatformsDropped Platforms

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IX. List of Dropped Platforms

Dropped Platforms

The following platforms compiler, and OS have been dropped as of this release:

• HP-UX 10.20 (PA 1.1)

• CRAY

The following platforms and compilers will be dropped in the next release:

• HP-UX 10.20

• HP-UX 11 (32-bit)

• SGI mips3

• Compaq Visual Fortran 6.0A (only Compaq Visual Fortran 6.6A or higher will be supported)

• DEC OSF1 4.0 (higher OS will be supported)

• IBM AIX 4.3.2 (higher OS will be supported)

• SUN Solaris 2.6 (higher OS will be supported)

• Compilers for SGI, DEC, IBM, and Intel will be upgraded in the next release

• Windows NT (only Windows 2000 and Windows XP will be supported)

All FORTRAN-77 versions will be dropped in the next release and will be replaced with FORTRAN-90 versions.

95Important NotesMSC.Marc 2003

X. Important Notes

MSC.Marc 2003

1. The startup script for MSC.Marc (run_marc or run_marc.bat) runs the job in the directory where the command is issued, even if a path to the input file is provided.

Example:

run_marc -j ../otherdir/job

The job runs in the current directory. All results files are created in the current directory. No files are created in ../otherdir; only the input file is read from there.

Filename extensions are now allowed in the command line options.

Example:

run_marc -j job.dat -u usersub.f

A new option: -dir directory allows a different working directory to be specified. All created files, scratch files, and results files except the log file and status file are created in the directory specified with this option. This option is not supported through MSC.Marc Mentat.

2. In parallel contact jobs, all nodes must be numbered sequentially.

3. When running any of the examples in the MSC.Marc New Features Guide or MSC.Marc Introductory Course, it is best to copy all the files (.proc, .mfd, .mud, .t16, .t19, etc.) in the example directory to the current, local directory. This is especially required for the examples where the procedure file uses the previously generated results file or model file to demonstrate the example.

4. Hardware Vendor Provided Solver

The hardware vendor provided solvers (solver 6) are available for parallel matrix solution. Exception: HP-UX 10.20 and Sun 64-bit version. In a parallel run using Domain Decomposition, this is utilized automatically. This feature can also be used in a serial run in which case only the matrix solution will be performed in parallel. There are two ways to activate this feature:

(1) Using the command line option -nthreads.

Example:

run_marc -v no -j test -nthreads 4

will run the job test.dat using four processors for the matrix solution. This is not available from within MSC.Marc Mentat.

(2) Using the environmental variable MARC_NUMBER_OF_THREADS. This variable is set to the number of processors to be used. Note that it needs to be defined in the same window as the one in which the job is started. If the job is started from within MSC.Marc Mentat, the variable needs to be set before MSC.Marc Mentat is started. If

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this variable is set and the -nthreads option is used, the value given by -nthreads will be used.

5. The parallel version of MSC.Marc is delivered with MPICH (public domain MPI) for most UNIX platforms. This version can be used for both single multiprocessor machines as well as for separate machines connected over a network. When running a job over the network a so-called host file should be used, see Installation and User Notes for Network version.

Note: The host file should not be used in a run on a single multiprocessor machine.

On most of the platforms using MPICH, it is possible to switch to hardware vendor MPI (a Fortran compiler is required for doing the switch). Only analyses on single multiprocessor machines are supported in the case of versions using hardware vendor provided MPI. An exception to this is the 64-bit HP version which fully supports the network parallel analysis with HP-MPI.

Note: There is a memory limit of 1 GB per domain for the parallel version on the Windows NT platform. This limit is 2 GB per domain on Windows 2000 and Windows XP.

6. Installation related:

i. If you get an error message of f77 not found or f90 not found when running a job with a user subroutine and you know there is a FORTRAN compiler on the machine, its path needs to be provided. A typical example would be the Sun platform where the f77 compiler may live in the /opt/SUNWspro/bin directory. This path must be added if you get the f77 error message.

ii. On a rare occasion, a job can fail to run on certain platforms with a message; for example, on DEC machines libUfor.so not found or on SUN machines libsunmath.so.1 not found. These files with extensions of .so are shared objects and the error message suggests that either the run time libraries are missing from the system or installed in a nonstandard place. This problem can be fixed with one of the following procedures:

a. Try relinking the version first by executing the make_marc script in the marc2003/tools directory and run the job with and without user subroutines.

b. If the problem persists, check if the .so file exists in the marc2003/lib/lib_shared directory. If it does exist, uncomment the following two lines in the run_marc script under marc2003/tools directory:

LD_LIBRARY_PATH = $DIR/../lib/lib_shared:$LD_LIBRARY_PATH

export LD_LIBRARY_PATH

If the first line already exists and points to some other directory, replace it with the new line. Run the job with and without user subroutines once again.

c. If the .so files do not exist in the marc2003/lib/lib_shared directory or if the lib_shared directory does not exist, contact your system administrator to off load the necessary run time libraries from the system CD.

97Important NotesMSC.Marc 2003

7. When using the -host command line option to run a MSC.Marc job, the output will automatically be written to the directories specified in the hostfile. For instance, when running a 4 domain MSC.Marc job as follows:

run_marc -jid jobid -host hostfile -nprocd 4

the output will be written for each domain to the directories as specified in the hostfile. By default, MSC.Marc Mentat always will write the hostfile to contain the directory specifications.

However, the following exception applies to the default described above. On Unix systems using the IBM cluster product POE or the Sun cluster product HPC, the -host command line option should never be used. Instead, the -dir command line option can be used to customize the location of the output. The user notes can be consulted for further information on how to use the -dir option.

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XI. Platform Specific Notes

Various Machine Notes

1. SGI Machines:

(1) When running the parallel version with (with hardware vendor provided MPI) the Arrays 3.2 version, the job may not run if the marc installation or run directory path name is very long. Normally, path names up to 256 characters are allowed in MSC.Marc, but there is a problem with the Arrays 3.2 version.

Remedy: install patch 3532 from SGI or upgrade to Arrays 3.3 or later

(2) The current version of MSC.Marc requires that the blas library is installed for user subroutines to work. This library is normally installed together with the compiler, but on some versions of IRIX they did not get installed automatically. This is the case for IRIX 6.5.2, 6.5.3, and 6.5.4.

For these versions, the fortran compiler runtime libraries in

ftn_eoe.sw and ftn_eoe.sw64

need to be installed.

(3) The user memory limit must be checked before running jobs that require a large amount of memory. This can be done with the use of the limit command. The value for memoryuse should be at least as large as that specified with the MAXSIZE value in the include (or include.bat) file. To increase this limit, you either have to rebuild the kernel or perform the following steps (requires superuser privilege):

suunlimit -h memoryuse

unlimit memoryusesu - <your username>

This will remove the memoryuse limits.

2. HP Machines:

(1) The HP-UX 10.20 executables have been built for PA-RISC 2.0 architecture. The architecture can be checked by running a command on the executable in the marc2003/bin directory as:

file marc.

The platform can be identified with the use of the command:

/usr/bin/getconf SC_CPU_VERSION.

If it returns a number greater than or equal to 532, it is a PA_RISC 2.0 system.

(2) On HP-UX 10.20, PHSS_17872 and PHSS_17225 (or newer) patches are needed by MSC.Marc Mentat.

99Platform Specific NotesVarious Machine Notes

(3) The HP-UX based Itanium2 version supports the following interconnect/protocol clusters for parallel processing over networks.

– 10/100 Base-T with IP

– Gigabit (GigE) with IP

– HF (Hyperfabric) with IP

– HF with (Hyper Messaging Protocol) HMP

All Itanium 2 machines come with 10/100 Base-T and gigabit (GigE) Network Interface Cards.

HF (Hyperfabric) is an optional device which is HP’s implementation of Myrinet.

HMP is a light weight protocol available over Hyperfabric hardware.

It will appear as the following software product if installed:HyprFabrc-00 B.11.22.00.06 PCI HyperFabric; Supptd HW=A6092A/A6386A

This application is HMP enabled, thereby allowing runtime determination of whether to use IP or HMP when HF hardware and supporting software are installed.

To this effect, the MPI_HMP environment variable should be set to ‘on’ for each line of the appfile.

The protocol used is chosen based on the network cards associated with the hostnames or IP addresses specified in the appfile.

The MPI_LOCALIP variable may be used to instruct mpirun to use a specific address assigned by /etc/ifconfig to the desired NIC in case it is different from the one returned by nslookup.

Performance advantage between IP and HMP protocols on HF interconnect depends on message traffic direction of streaming, and message size.

IP performs better than HMP when message traffic is streaming in one direction, and the message size is small.

(4) The HP 64-bit versions can only be run on 64-bit enabled HP-UX. This can be checked with the use of the command:

/usr/bin/getconf KERNEL_BITS

If the returned value is 64 then the system is 64-bit enabled.

(5) Large file support (files > 2 GB) are enabled via the /etc/fstab file. The option largefiles must be added to the file-system entry for each device that will need to support large files.

3. IBM-SP Machines:

MP_EUIDEVICE=css0

This specifies that the tasks will use the High Performance Switch for communication.

Note: A group of workstations connected by an ethernet network would use:

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100

MP_EUIDEVICE=en?

where:

? specifies the network device adapter [ 0, 1, 2, ..., n ]

MP_EUILIB=ip

This specifies that the task will use "ip" protocol when sending messages to each other. Not the best performance, but always gets through the switch.

MP_EUILIB=us

This gives the best performance over the switch, but causes delays in starting jobs on older versions of PSSP.

Note: A group of workstations communicating over a network would have to specify "ip" since "us" is only available for communication over the switch.

#MP_RESD=yes

No longer used for job scheduling with LoadLeveler. Required for older version of PSSP which uses the Partition Manger to schedule jobs.

MP_RMPOOL=1

This specifies a "Pool" of nodes that LoadLeveler will use for scheduling the tasks if the file host.list does not exist in the directory where the job starts.

MP_HOSTFILE="NULL"

This specifies the file that contains the list of nodes to schedule the tasks on will have the default name "host.list" if it exist.

#MP_HOSTFILE=$DIR/tools/host.list

Allows the user to specify any file name and its location, instead of host.list in the directory where the job starts.

MP_INFOLEVEL=0

Specifies the amount of information that LoadLeveler/POE gives the user about his job. The zero specifies "none" and the user would not know what happened if his job failed. Use a value of 2 (default).

4. IBM Machines:

The OpenGL version of MSC.Marc Mentat may not operate properly on some IBM platforms. The runtime libraries patch 4.3.3.25 is required. The type of graphics adapter may be displayed using the lsdisp command.

101Platform Specific NotesVarious Machine Notes

5. 64-bit IBM Machines:

Go to /etc/security on the system and change the value in the limits file to the following.

Default:fsize = -1core = -1cpu = -1data =-1rss = -1stack = -1nofiles = 2000

After changing this, please check again ulimit -a. It should return unlimited in all the fields. If not, you may have to reboot the system.

Once you change the ulimits, you should be able to write a 2GB file on your standard journal file system.

To write 7 GB file, you have to create another file system with large file enabled journal file system.

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XII. Security

Security Notes

The 2003 release stores the license manager (lmgrd) and the vendor daemon in a directory named flexlm for Windows NT, and for UNIX platforms it is flexlm/<platform>, where <platform> is aix, alpha (Tru64), hpux, irix, linux, solaris, or sun. The default location for the license file is flexlm/licenses.

LAPI security has been implemented in the products. The capabilities that require a license are given below with feature names as required in the license file.

i. MARC one token required to run one single processor job or one instance of a multiple processor (parallel) job.

ii. MARC_Parallel one token required per processor in a parallel run (for example, a four processor job requires one MARC token and four MARC_Parallel tokens).

iii. MARC_Mesh2D one token required for each run requiring automatic 2-D remeshing feature in MSC.Marc.

iv. MARC_Mesh3D one token required for each run requiring automatic 3-D remeshing feature in MSC.Marc.

v. MARC_ShapeMemory one token required for each run using shape memory model.

vi. MARC_MetalCutting one token required for each run modeling metal cutting operation.

vii. MARC_CrossSection one token required for each run using the Cross Section option.

viii. MARC_Electrical one token required for Joule-mechanical and piezoelectricity.

ix. Mentat one token required for each instance of MSC.Marc Mentat.

x. MARC_Hexmesh one token required for each instance of Hexahedral mesher.

xi. Mentat_ACIS one token required for each instance of ACIS when working (import/export) with ACIS based models.

xii. Mentat_ITI_Access one token required for each instance of, or exporting a file using the DXF, IGES, or VDAFS translators.

xiii. Mentat_CMOLD one token required for each instance of CMOLD when working (import/export) with CMOLD based models.

The following types of licenses are available with the products:

i. Nodelocked, counted

ii. Nodelocked, uncounted

103SecuritySecurity Notes

iii. Floating (concurrent)

iv. Campus

v. Demo

Please refer to the installation guide for more information on security or contact your local MSC representative.

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Documents

MSC.Marc and MSC.Marc Mentat - MSC Software Corporation