Solid Shell Element

ANSYS 9.0 Preview IIANSYS, Inc. Proprietary© 2003 ANSYS, Inc.

ANSYS 9.0Preview II

Grama Bhashyam


Topics• Mechanics

– Solid Shell Element– Rezoning – 2D– Spotwelds– Pre-Integrated Shell/Beams Sections– Follower Forces– NonLinear Diagnostics and Contact– Temperature Dependent Curve Fitting– Frequency Dependent Harmonic Analysis– Local CYS for Function BC’s– Static Cyclic Symmetry– Component Based Acceleration– CMS Superelements

• Multifield Solver– Flotran Remeshing for Multifield Solver

• Electric and Magnetic Analysis– Electrostatics and Magnetic Forces Calculation– High Frequency Electromagnetic Enhancements– Thermoelectric Analysis


Solid Shell Element


Problems associated with a shell theory based FEM

• Nonlinear MPCs or transitional elements are required for connecting shell and solid elements.

• Treatment of variable thickness is unclear.

• Definition of contact interaction needs special attention.

• Difficulties in the specialization of general three-dimensional material laws to plane-stress state.

• Complicated update of rotations in geometrically nonlinear analyses.

ANSYS 9.0:Solid Shell Element


Numerical locking in low-order 3D solid elements

• The error in the kinematic approximation with linear 3D solid elements becomes apparent in bending dominant problems.

This error is magnified as the thickness decreases, which beyond a certain ratio may make the FE model excessively stiff.

• Current element technologies, such as the enhanced strain (or extra shapes), are not sufficient to remedy this numerical locking in linear 3D solid elements.


0

0.2

0.4

0.6

0.8

1

1.2

1 6 11 16 21 26

Number of Elements Per Edge

Nor

mal

ized

Max

. Def

lect

ion

Solid185 (enhanced strain)


Element Summary• Involves only displacement

nodal DOFs and features an eight-node brick connectivity. Thus the connection problem between solid and shell elements can be eliminated.

• Performs well in simulating shell structures with a wide range of thickness (from extremely thin to moderate thick).

• Is compatible with 3D constitutive models and automatically accounts for thickness change.

• Performs well for both flat-plate and curved shells.


1

8

6

4 7

53

R1

R2

R3

X1

X2X3

2

∂∂

∂∂

∂∂

=

∂∂

∂∂

∂∂

=

∂∂

∂∂

∂∂

=

3

3

3

2

3

13

2

3

2

2

2

12

1

3

1

2

1

11

,,

,,

,,

rx

rx

rxR

rx

rx

rxR

rx

rx

rxR


FE solution convergence relative to mesh refinement

0

0.2

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0.8

1

1.2

1 6 11 16 21 26


Nor

mal

ized

Max

. Def

lect

ion

Shell181 (enhanced strain)Solid185 (enhanced strain)

SolidShell 190

Normalized shell thickness ( t / L) : 0.001, linear static analysis



FE solution convergence relative to mesh refinement

Normalized plate thickness ( t / L) : 0.01, linear static analysis

0

0.02

0.04

0.06

0.08

0.1

0.12

0 5 10 15 20 25 30


Def

lect

ion

at L

ocat

ion

4

Shell181 (enhanced strain)

Solid185 (enhanced strain)

Solid45 (extra shapes)

SolidShel 190



FE solution from different modelst/L = 0.01, linear static analysis

Maximum Displacements ------------------------------------------------------------

Ux Uy Uz

SolidShell190 343.41 -642.89 -1395.8

Shell181 Enh 341.91 -639.15 -1395.9

Solid185 Enh 257.12 269.73 -882.97



FE solution convergence relative to mesh refinementgeometrically nonlinear static analysis

-0.2

-0.15

-0.1

-0.05

0

0.05

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0.15

0 10 20 30 40 50 60 70 80 90

# elements per edge

Rad

ial D

isp.

At t

wo

corn

ers

Shell181 (pt1)solid190 (pt1)Solid185 (pt1)shell181 (pt2)solid190 (pt2)solid185 (pt2)



Modal Analysis of a Hemi-sphere Shell

thickness = 0.001 mesh density = 15 x 15 (Thin Shell)Mode Shell181 Enh Solid185 Enh SolidShell 190

1 3.07759484 8.239738235 3.0717603832 21.24648643 103.9636569 21.228723943 53.86043052 350.1158379 53.829848284 99.48796565 758.7461212 99.481637175 158.4547881 1303.958847 158.47231616 232.5992189 1927.192569 232.66981987 325.8971451 2484.333703 326.0458065

thickness = 0.1 mesh density = 15 x 15 (Thick Shell)Mode Shell181 Enh Solid185 Enh SolidShell 190

1 268.3336331 233.1024418 233.08097732 1401.119808 978.7538942 980.01414573 2400.852477 1761.461958 1763.3263394 3284.527205 2224.35367 2225.6287235 3590.50519 2403.006279 2402.6392126 3670.531134 3157.10644 3155.3068547 4179.724049 3418.795507 3420.088344



FE solution from Different Models – Lateral Buckling

L = 100.0 W = 5.0 T = 0.2 (Thin Shell)Mode Shell181 Enh Solid185 Enh Solid190 Enh

1 -5.33E-02 -3.88E-02 -5.32E-022 -1.99E-02 3.88E-02 -1.99E-023 1.99E-02 0.14182488 1.99E-024 5.33E-02 0.34611073 5.32E-02

L = 100.0 W = 5.0 T = 2.0 (Thick Shell)Mode Shell181 Enh Solid185 Enh Solid190 Enh

1 17.892629 18.661164 18.1459592 47.598787 50.793036 48.3937213 82.888858 91.861602 84.700194 128.51412 149.1249 132.4327



Car roof assembly part under pressure load (linear static analysis)

Max. Deflection:SOLID186: 0.001521

SOLID190: 0.001575

SOLID185: 0.001290


Rezoning – 2D


Why?

• Mesh distortion terminates analysis

ANSYS 9.0:Rezoning


Solution: rezoning

• What is rezoning?– Remesh base on the deformed domain at a

selected substep– Map the solved variables and achieve equilibrium

based on the mapped variables– Resume the solution based on the new mesh

• Long term goal:– Fully automatic rezoning with different adaptive

criteria to overcome mesh distortion and reduce discretization error

ANSYS 9.0:Rezoning


Current status

• Manual rezoning for 2D analysis– Elements:

• Plane 182, B-Bar formulation with or without mixed u/P formulation

• All stress states, i.e. plane strain, plane stress, axisymmetric, generalized plane strain

– Materials:• All hyperelastic materials (TB, Hyper…) • Analysis type:

– Static analysis with nlgeom, on

ANSYS 9.0:Rezoning


Current status (Cont.)

– Loads and boundary conditions:• Displacements• Forces• Pressures• Nodal temperature, applied by BF,TEMP…

– Remesh• Manual remeshing

– Select the elements to remesh– Generate a area– Create the new mesh by ANSYS meshing commands

– Based on multi-frame restart files

ANSYS 9.0:Rezoning


How Does it work ?

• Based on solved data/batch,list

/prep7

et,1,182...tb,hyper,1,,.....rect,0,b,0,h,esize,el,0,amesh,1d,....

/solunlgeom,ontime,1NSUBST,.....solve

ANSYS 9.0:Rezoning


How does it work, a pseudo input

• 4 basic steps needed– Step 1

• Retrieve data– Step 2

• Select the region• Generate area• Create new mesh• Transfer load/Bc

– Step 3• Map variables

– Step 4• Resume solving

ANSYS 9.0:Rezoning


Step 1: Retrieve data

• Command:

ANSYS 9.0:Rezoning


Step 1: Retrieve data (cont.)

• Functionality:– Check the needed files

• The RDB, RST, RXXX and LDHI files– Rebuild the data environment at the

requested substep by REZONE command– Update the

nodes to the deformed geometry

ANSYS 9.0:Rezoning


Step 2: Remesh

1. Select the region to remesh– To start by START option

ANSYS 9.0:Rezoning


Step 2: Remesh

– Select any region on the deformed domain • By any element selection commands • By selecting elements to generate the region to

remesh• The region should have:

– Same material, – Same element type, esys and keyopts– Same thickness (real constant) for plane stress– It can be the whole or part of the domain

ANSYS 9.0:Rezoning


Step 2: Remesh (Cont.)

2. Generate an area to create new mes

ANSYS 9.0:Rezoning



– Functionalities:• Generate an area to create mesh in rezoning• Check the validity of the selected region• Keep compatibility with its neighbors

ANSYS 9.0:Rezoning



3. Create new mesh by– Any mesh control

commands (lesize, smrtsize, shpp,..)

– Amesh

• Multiple horizontal Rezoning– Another region can

be chosen and remeshed following the same procedure (in future)

ANSYS 9.0:Rezoning


New Mesh With BC


4. Transfer boundary conditions automatically by DONE option

Old Mesh With BC

DONE Will be END in future

ANSYS 9.0:Rezoning


Step 3: Map solutions

• Intorduce extra substeps to balance the residuals– Rebalance factor: How much residual force has

been balanced, from 0.0 to 1.0– Note: time /external load unchanged

ANSYS 9.0:Rezoning


Step 3: Map solutions (Cont.)

• Output information ( Mapsol, 10)

ANSYS 9.0:Rezoning


Step 3: Map solutions (Cont.) ANSYS 9.0:Rezoning


Step 4: Resume the solution

• Command:– Regular multi-frame restart by

• Antype,,restart…• Solve

ANSYS 9.0:Rezoning


New files

• Vertical Multiple Rezoning (in future)» Rezone the same/other area during different

time/substeps» All models and solved variables saved in files» Can be restarted from any rezoned model at any

time » Maximum number of rezoning: 99

File name

Regular Run

Rezone 0 Rezone 1 Rezone 2 Rezone 11 Rezone NNRDB RDB RD01 RD02 RD11 RDNNRXXX RXXX RXXX RXXX RXXX RXXXLDHIRST RST RS01 RS02 RS11 RSNN

LDHI

ANSYS 9.0:Rezoning


Post processing

• Post1 enhancement– SET,List,,Fact

• where Fact is used to control which files are to be listed:• Fact = ALL or blank lists all files (rst,rs01,rs02,etc.)• Fact = LAST lists the last file only (e.g. rs02)• Fact = num of rezoning (e.g. 01) lists only file rsxx

– Example: SET,List,,All

– Other enhancements are coming soon

ANSYS 9.0:Rezoning


Spotwelds


New example


Mesh Independent Spot Weld

• In automotive and/or aerospace industries, many applications require modeling of spot welds between two or more thin parts

• The strength and fatigue properties of thin sheet components are considerably influenced by spot welds

• The traditional model of spot welds:– Matching meshes of different parts at spot weld connection

points.– Effects of spot weld radius is not taken into account– underestimates the strength of the spot weld connection

ANSYS 9.0:Spotweld


• Parts can be meshed independently• The spot weld can be located anywhere between multiple parts

that are to be connected in a finite element model regardless ofthe mesh.

• A spot weld is defined by the surfaces to be connected and a spot weld node near the surfaces. The spot weld node determines the location of spot weld

• The location of the spot weld can be independent of the locationof the nodes on the surface to be welded.

• The approach takes into account of effects of spot weld radius. ANSYS will generate – RBE3 type MPC via a contact pair on each spot weld surface. The

radius defines the range of force distribution.– A beam element to link the two adjacent surfaces. The beam has

physical radius.• The spot weld can be either rigid or deformed

Mesh Independent Spot Weld ANSYS 9.0:Spotweld


Create a New Spot Weld Set ANSYS 9.0:Spotweld


Create a New Spot Weld Set

SWGEN, Ecomp, SWRD, NCM1, NCM2, SND1, SND2, SHRD, DIRX, DIRY, DIRZ, ITTY,I CTY

ECOMP – Spot weld set name. It is the element component and it is used to identify set of spot weld for list, output, and adding more surfaces.

NCM1/NCM2: – Spot weld surfacesPre-defined node components (for select)Meshed areas (for pick)

SND1: – First spot weld node. It determines the location of spot weld. It can be one of node on surface NCM1 or an independent node near the surface. ANSYS will determine the actual location by projecting it onto surface NCM1.

Spot weldsurface 1

Spot weld node 1After projection

Original position of spot weld node 1

Spot weldsurface 1

Spot weld node 1After projection

Original position of spot weld node 1

Projection onto surface Projection direction specified by user

ANSYS 9.0:Spotweld



SWRD – Spot weld radius. Each spot weld has a circular projection onto the spot weld surface. By the definition of each contact pair, ANSYS will form RBE3 type constraint equations internally which distribute internal force of contact node (i.e. spot weld node) to the target nodes lying with in the region of spot weld radius.

CONTA175(spot weld node 1)

Spot weldsurface 1

TARGE170 elements

Spot weld radius

CONTA175

Nodes to be constrained

ANSYS 9.0:Spotweld



Beam element – connects two spot weld surfaces.Rigid Link is a default : MPC184 with KEYOPT(1)=1Deformed Link : if current defined element type is BEAM188 with proper Material ID and section ID (solid circle)

Spot weldsurface 1

Spot weld node 1

Spot weldsurface 2

Spot weld node 2 A beam elementMPC184/BEAM188

Example:

MP,EX,3,200000000000. ! define spot weld material propertiesMP,NUXY,3,0.3SECTYPE,3,beam,csolid ! define a cylinder beamSECDATA,2.75e-002 ! beam circular radiusET,3,188 ! define a deformed spot weldTYPE,3MAT,3SECNUM,3*SET,NODE1,9000 ! define a spot weld nodeN,NODE1,0.1,0.5,10.2 ! define location of spot weld

SWGEN,SWELD1,2.75e-2,2,3,NODE1 ! Spot sweld name=SWELD1,! RADIUS=2.75e-2,!Spot weld surfaces=AREA 2 and 3.

ANSYS 9.0:Spotweld


Add more surfaces ANSYS 9.0:Spotweld


Add more surfaces

SWADD, Ecomp, SHRD, NCM1, NCM2, NCM3, NCM4, NCM5, NCM6, NCM7, NCM8, NCM9Ecomp - The name of an existing spot weld set which composes contact, target and beam elements for the spot weld definition.SHRD - Search radius. It defauts to 4 times of spot weld radius SWRDNCM1-NCM9 - Surfaces to be added the spot weld set. Each surface can input by a pre-defined node component or by a meshed area.

- SWADD command can be repeated to add more surfaces- Max. number of allowabl2 surfaces (including two from basic set) = 11.

Spot weldsurface 1

Spot weld radius

Spot weld node 1

Spot weldsurface 2Spot weld node 2


Basic spot weld setOriginal position of spot weld node 1

Beam2

Beam1


More surfaces

Beam3

ANSYS 9.0:Spotweld


Mesh-Independent Spot Weld

SWDEL, Ecomp- Delete spot weld set- Ecomp - The name of an existing spot

weld set.- If Ecomp = ALL (default) all the spot

welds are deleted

ANSYS 9.0:Spotweld



SWLIST, Ecomp- List spot weld set- Ecomp - The name of an existing

spot weld set.- If Ecomp = ALL (default) all the spot

welds are Listed

• In POST1 not only elements and contact pairs are listed but also output beam results. For deformed BEAM188 both forces/moments and stresses are listed.

ANSYS 9.0:Spotweld



Beam188

Conta175

Targ170Output

ANSYS 9.0:Spotweld



Beam188

Conta175

Targ170Output

ANSYS 9.0:Spotweld


Pre-integrated shell/beam sections


Preintegrated Shell Section

• A,B, D and E sub-matrices are symmetric – Allow only bottom symmetric half to be defined – MT, BT are generalized stresses caused by a fully

constrained unit temperature rise• θ is the current temperature, θI is reference

temperature• A,B,D,E,MT,BT can be defined at 6 temperatures

independently• Mass Density of shell/unit area may also be defined

at 6 temperatures

( )

−−

=

BTMT

DBBA

MN I

T θθκε

=

2

1

2221

1211

2

1

γγ

EEEE

SS

ANSYS 9.0:Pre-integrated Shell Sections


Benefits/Limitations

• Benefits– Missing capability for 4

node shells in ANSYS– Faster: no material point

calculations or storage– Third party software

provide the section stiffness for layered, sandwich or other constructions

– Optimization with homogenized behavior

• Limitations– No output of stresses

• Section resultants (membrane forces and bending moments are available)

– Ability to specify initial stresses is lost

– Linear material behavior– Birth and death is not

supported (currently)– Not meaningful to use at

finite strains • Thickness is not

updated– Offset is not allowed

ANSYS 9.0:Pre-integrated Shell Sections


Nonlin. Beam General Sections

• We define the “section stiffness” directly as a function of– “section strain” and– Temperature

• There is no material input necessary

• We also define mass density and thermal expansion coefficient– One temp. input per node

(no variation across section)

=

2

1

2

1

2

1

2

1

2

1

2

1

),(),(

0

),(),(

0),(),(

γγθκκε

εε

εε

εε

tSFtSF

tQtF

tFtAx

SSTMMN

CurvatureBen

ding

Mom

ent

ANSYS 9.0:Nonlinear Beam Preintegrated

Sections


Benefits/Limitations

• Why?– Allows nonlinear

relationships (elastic and elasto-plastic) in terms of generalized stresses and generalized strains

– Very efficient– Allows results from

experiments or another slice analysis as input

• Limitations– No coupling between Axial

and Bending behaviors– Allows nonlinear elastic and

plastic behavior– 20 points of stress-strain

supported– Stress-Strain curve may be

supplied at 6 temperatures– Not applicable for “Warping”

Key-option– Only SMISC quantities are

supported• PRSSOL is meaningless

ANSYS 9.0:Nonlinear Beam Preintegrated

Sections

Beam188/Beam184


Follower Forces


Follower load example

P/100P P

Nodal loads

Follower loads

ANSYS 9.0:Follower load


FOLLW201 element

• A “one” node element – Must be used with nodes

that are attached to shells & beams (uses 6 d.o.f per node)

– No material, section, esys attributes necessary

– Contributes to “stiffness”only for NLGEOM,ON

• NROPT,UNSYM preferred• Follower stiffness

symmetrized for NROPT,FULL

• Real constants– 6 values

• First three n1,n2,n3 entrees are direction cosines of the force vector

• Next three m1,m2,m3 entrees are direction cosines of the moment vector

– The vectors defined by real constants will evolve with deformation (follow the displacements)



Follower loads

• Follower loads are non-conservative

• Introduce unsymmetric load stiffness contributions

• Introduce stability issues; flutter, dynamic stability

• Often counter intutiveand non-predictable

• A simple cantilever with follower load has flutter instabilities

• SFE command is used to specify load magnitude

• FACE 1 – force• FACE 2 – moment


sfe,nel+1,1,pres,1,-load


Nonlinear Diagnostics & Contact


Diagnostic Tool

• Visualization and adjustment tools for initial contact status– CNCHECK, DETAIL: evaluate Contact Pair specifications– CNCHECK, ADJUST: move contact nodes to target to close

gap or reduce penetration– CNCHECK, POST: view contact initial status before solving– CNCHECK, RESET: reset contact default settings

ANSYS 9.0:Contact


Diagnostic Tool

• NLDIAG,CONTACT,on– File Jobname.cnd is written during

iteration/substep/loadsetp– Lists on a pair-based items.– Identify when and how contact occurs.– When divergence occurs, it

determines the regions where contact is unstable.

ANSYS 9.0:Contact


Penalty based shell-shell Assembly

• Prevent overconstraint when contact occurs on both sides of shell

Surface-surface contact:

Only translation DOF’s are constrained

Penalty based shell-shell:

Both translation & rotation DOF’s are constrained

Rotationalresistance

ANSYS 9.0:Contact


Temperature Dependent Curve Fitting


Purpose

• The purpose of the project is to generate coefficients from temperature dependent experimental data.

• This is applicable to all HyperElastic, ViscoElastic(Prony Series) and Implicit Creep models.

• This is an extension of the existing curve fitting capabilities for all the above mentioned material models.

ANSYS 9.0:Temp. Dependent Curve

Fitting


Experimental Data Definition

• Add data at various temperatures and as many as you like in the following format. This is applicable to all experimental data types.(uniaxial, biaxial, shear, volumetric, creep,…)Example;/temp,1000.0 10.1 20.2 3

• Only one temperature per file.


Fitting


New Functionality

• A new option is added to enable temperature dependent curve fitting.• With the temperature dependent option on, The solver filters

experimental data depending on the temperature and generates separate sets of coefficients at corresponding temperatures.

• There are two solution procedures– Set a temperature and solve. Repeat this for all other temperatures,

verify/view the results and save the coefficient to ansys material database.– Set the temperature to “all” and solve. This will solve for all temperatures at

once. Verify/view the results and save to database.• The plot page plots the curves at all temperatures.


Fitting


Step by step procedure

• Import Experimental Data – One temperature per file

• Pick an appropriate material model.• Enable temperature dependent curve fitting (tbft,set,categ,func,opt,tdep,1)• Solution

– Set the temperature (tbft,set,categ,func,opt,tref,temp1)– Solve– Set the temperature (tbft,set,categ,func,opt,tref,temp2)– Solve ……

Or– Set the temperature (tbft,set,categ,func,opt,tref,all)– Solve command solves for coefficients at all temperatures.

• Verify the results using plots for all temperatures.• Save the data to Ansys database.


Fitting


Sample Script

/prep7! Define Materialtbft,fadd,1,hyper,moon,2

! Define Uniaxial Datatbft,eadd,1,unia,unia-100.exptbft,eadd,1,unia,unia-200.exptbft,eadd,1,unia,unia-300.exptbft,eadd,1,unia,unia-400.exp

! Define Volumetric Datatbft,eadd,1,volu,volu-100.exptbft,eadd,1,volu,volu-200.exptbft,eadd,1,volu,volu-300.exptbft,eadd,1,volu,volu-400.expContd ………..


Fitting


Sample Scripts contd.

tbft,set,1,hyper,moon,2,tdep,1

tbft,set,1,hyper,moon,2,tref,100tbft,solve,1,hyper,moon,2,0



tbft,set,1,hyper,moon,2,tref,400tbft,solve,1,hyper,moon,2,0a

tbft,list,1

tbft,fset,1,hyper,moon,2tblis,all,allfini


Fitting


Temperature dependent Uniaxial Experimental DataANSYS 9.0:

Temp. Dependent Curve Fitting


Solver PageANSYS 9.0:

Temp. Dependent Curve Fitting


HyperElastic Polynomial –Uniaxial Data Fit at four temperatures


Fitting


Saved Coefficients inAnsys Material GUI


Fitting


Frequency Dependent Harmonic Analysis



• Objectives– Frequency and temperature dependent

elastic properties– Frequency and temperature dependent

damping coefficient– Calculate damping matrix from elements – Support full harmonic response analysis



• Equation of motion

[ ]{ } [ ]{ } [ ]{ } { }FuKuCuM =++ &&&

[M] – mass matrix

[K] – stiffness matrix[C] – damping matrix

[ ] [ ]∑ ωµω= ))(),(E(KK e

[ ] [ ]∑= eCC [ ] [ ]ee K)(sC ω=

s – structure damping coefficient



– Elasticity• TB,ELASTIC Command

Isotropic elasticity (Ex, NUxy)Orthotropic elasticity (Ex,Ey,Ez,Gxy,Gxz,Gyz,Nuxy,Nuxz,Nuyz)Use TBFIELD to define frequency and temperaturedependent elastic properties

– Damping coefficient• TB,SDAMP (SDAMP - stand for structure damping)

Use TBFIELD to define Frequency and temperaturedependent damping coefficient

– Element supports• 182, 183, 185, 186, 187 for all stress states



• Elasticity– The Command

TB,ELASTIC,MAT,NTEMP,NPTS,TBOPTMAT

Material numberNTEMP

Number of temperatureNPTS

Number of data point2 – for isotropic elasticity9 – for orthotropic elasticity



• Elasticity– The Command

TB,ELASTIC,MAT,NTEMP,NPTS,TBOPTTBOPT elastic data table optionIEL isotropic elasticity behavior, the

defaultOELN orthotropic elasticity behavior

with minor Poisson ratio



• Procedure• Use ANSYS full harmonic analysis procedure

ANTYP,HARM• Parallel to other ANSYS full harmonic analysis

with damping effect through commands such as ALPHA and BETA; MP,DAMP; DMPR; …

• The DAMPING matrix from TB,SDAMP is additive to other damping matrix, and therefore the damping effect is “add on”

• TB,ELASTIC can be used with TB,SDAMP and also MP,DAMP;ALPHA and BETA; DMPR.



• Example• Define an elastic data table with frequency dependence

TB,ELASTIC,1, ,2 ! Elastic data tableTBFIELD , FREQ,25 ! First frequency valueTBFIELD , TEMP,25 ! First temperature valueTBDATA,1,2.50e11,0.3 ! E and µTBFIELD ,FREQ,50 ! Second frequency valueTBDATA,1,2.0e11,0.3TBFIELD ,TEMP,50 ! Second temperature valueTBFIELD ,FREQ,75 ! Third frequency valueTBDATA,1,1.5e11,0.3TBFIELD ,FREQ,100 ! Forth frequency valueTBDATA,1,1.0e11,0.3



• Example• Define a damping coefficient data table with frequency

dependence TB,SDAMP,1, ,1 ! damping data tableTBFIELD , FREQ,25 ! First frequency valueTBFIELD , TEMP,25 ! First temperature valueTBDATA,1, 0.2 ! Damping co.TBFIELD ,FREQ,50 ! Second frequency valueTBDATA,1, 0.19TBFIELD ,TEMP,50 ! Second temperature valueTBFIELD ,FREQ,75 ! Third frequency valueTBDATA,1, 0.18TBFIELD ,FREQ,100 ! Forth frequency valueTBDATA,1, 0.17



• Example– SOLUTION procedure

/SOLUTIONANTYPE,HARMIC ! Harmonic response analysisHROPT,FULL ! Full harmonic responseHROUT,OFF ! Turn off printoutHARFRQ,25,400 ! Frequency rangeNSUB,16,,16



• Example: Cantilever beam subject to uniform pressure



• Material data

0.0E+00

5.0E+10

1.0E+11

1.5E+11

2.0E+11

2.5E+11

3.0E+11

0 100 200 300 400

Young's modulus as function of frequency



• Material data

Damping coefficient as function of frequency

0

0.05

0.1

0.15

0.2

0.25

0 100 200 300 400


0.0E+00

2.0E-07

4.0E-07

6.0E-07

8.0E-07

1.0E-06

1.2E-06

0 100 200 300 400 500

Results from FDM

Expected results


• Comparison of displacement

di

Note:Reference solution is obtained by defining material properties with the corresponding frequency at every load step



• On going development– Frequency dependent anisotropic elasticity– Extension to support SHELL181,

BEAM188, BEAM189, LINK180, SHELL208, SHELL209


0.0E+00

2.0E-07

4.0E-07

6.0E-07

8.0E-07

1.0E-06

1.2E-06

0 100 200 300 400 500

Results from FDM

Expected results


• Comparison of displacement

di

NoteReference solution is obtained by using material property defined by MP and change the property with the frequency every load step


New Material DefinitionStress vs. Plastic strain Curve


Requirements

• Directly define stress vs plastic strain data for multilinear isotropic hardening plasticity (MSIO)

• Directly define stress vs plastic strain data for multilinear kinematic hardening plasticity (KINH)


Stress Plastic Strain Data

• The commandTB,PLASTIC,mat,ntemp,npts,TBOPTmat = material numberntemp = number of temperaturenpts = number of stress plastic strain pointsTBOPT = MISO for isotropic hardening

= KINH for kinematic hardeningNote:The first data point is always the yield stress with zero plastic strain.



• Example multilinear isotropic hardening plasticity

TB,PLASTIC,1, ,10,MISOTBPT,, 0.000000, 0.3000D+05TBPT,, 0.000378, 0.3875D+05TBPT,, 0.000955, 0.4500D+05TBPT,, 0.001617, 0.5000D+05TBPT,, 0.002406, 0.5312D+05TBPT,, 0.003236, 0.5563D+05TBPT,, 0.004067, 0.5813D+05TBPT,, 0.004940, 0.6000D+05TBPT,, 0.006771, 0.6250D+05TBPT,, 0.010561, 0.6560D+05

Stress vs. plastic strain curve

0

10000

20000

30000

40000

50000

60000

70000

0.000 0.002 0.004 0.006 0.008 0.010 0.012



• Example for a multilinear kinematichardening plasticity

TB,PLASTIC,1, ,10,KINHTBPT,, 0.000000, 0.3000D+05TBPT,, 0.000378, 0.3875D+05TBPT,, 0.000955, 0.4500D+05TBPT,, 0.001617, 0.5000D+05TBPT,, 0.002406, 0.5312D+05TBPT,, 0.003236, 0.5563D+05TBPT,, 0.004067, 0.5813D+05TBPT,, 0.004940, 0.6000D+05TBPT,, 0.006771, 0.6250D+05TBPT,, 0.010561, 0.6560D+05

Stress vs. plastic strain curve

0

10000

20000

30000

40000

50000

60000

70000

0.000 0.002 0.004 0.006 0.008 0.010 0.012



• TB,PLASTIC applies whenever TB,MISO or TB,KINH apply

– TB,PLASTIC,,,,MISO is equivalent to TB,MISO– TB,PLASTIC,,,,KINH is equivalent to TB,KINH– TB,PLASTIC can be combined with other material

models, such as CHABOCHE, CREEP, RATE, HILL

– Use TBTEMP to define a temperature dependent data table

– Support elements 180, 181, 182, 183, 185, 186, 187, 188,189, 208, and 209


Preprocessing


• Function loads can now interpret (x,y,z) in local coordinate system

ANSYS 9.0:Sim. Support


• Post1 surface calculations- New “Cylinder” surface. Creates a cylindrical cut through the model of user specified radius and orientation.

• Map results on to the cylindrical surface to perform calculations

ANSYS 9.0:Sim. Support


Static Cyclic Symmetry


Static Cyclic Symmetry

• Plotting of /CYCEXPAN’ded B.C’s in POST• B.C. application through ‘Picking’• Point loads and Surface loads

• B.C. through nodes, keypoints picking to apply forces and displacements

• B.C. through picking - pressure on elements, lines, areas and displacement on lines and areas

• Verify results and compare with commands

• Imaginary loads (F, SF, D)• Post data structure – real and imaginary

results

ANSYS 9.0:Linear Dynamics


B.C. plotting in POST

B.C. through picking - areas

AREA LKEY LOAD LABEL VALUE(S)

3 1 PRES -200.00 0.0000 SECTOR 1

3 1 PRES -200.00 0.0000 SECTOR 3

9 1 PRES 10.000 0.0000 SECTOR 2

9 1 PRES 10.000 0.0000 SECTOR 5

10 1 PRES 10.000 0.0000 SECTOR 2

10 1 PRES 10.000 0.0000 SECTOR 5

12 1 PRES 20.000 0.0000 SECTOR 7



Component based Acceleration


Component Based Acceleration

• Apply apply inertia forces on different element components, based on the accelerations on the different parts of the structure.CMACEL, CM_NAME, CMACELX, CMACELY, CMACELZCM_NAME The name of the element component

CMACELX, CMACELY, CMACELZ

Linear acceleration of the element component CM_NAME in the global Cartesian X, Y, and Z axis directions, respectively.



Example/prep7…nsel,s,loc,z,0,-72esln,,1cm,roof1,elemnsel,s,loc,z,-75,-140eslncm,roof2,elem nsel,s,loc,z,-150,-220esln,,1cm,roof3,elemnsel,s,loc,z,-225,-300eslncm,roof4,elemesel,allnsel,alFini

/soluantype,staticcmacel,roof1,,0.36cmacel,roof2,,0.37cmacel,roof3,,0.38cmacel,roof4,,0.39solvefini



CMS - Superelements


Expansion in transformed location

• Expand the substructure results in transformed location if SETRAN or SESYMM command is applied in USE pass.

1. SEEXP, Sename, Usefil, Imagky, ExpoptExpopt

Key to specify whether the superelement expansion pass 2. RSTOFF, Lab, OFFSET

Offsets node or element IDs in the FE geometry record.



Example

!left wing is from right wing in USE pass/prep7et,1,50se,RightWingsesymm, LeftWing, X, 100, se2, subse,se2cp,...fini

! expansion Pass /assign,rst,rightwing,rst/solutionexpass,onseexp,rightwing,use, ,onrstoff, node, nof2rstoff, elem, eof2numexp,allsolvefinish



CMSFILE command enhancement

• Handle the CMS result file, but also other types of result file. So, the user can keep FEM parts in CMS analysis and postprocessthe substructure expanded result files and FEM result files together.

CMSFILE, Option, Fname, Ext, CmsKeyCmsKey

Valid only when adding a results file (Option = ADD or ALL), this key specifies whether or not to check the specified .rst file to determine if it was created via a CMS expansion pass:ON — Check (default).OFF — Do not check.



Re-meshing for Ansys Flotran inMultiField solver


Motivation

• For FSI problem when fluid mesh is highly distorted (affect the accuracy) or mesh fails in morphing

• Improve the accuracy when the mesh was distorted by ALE mesh moving scheme.

• Enable user to solve FSI problem with large domain changes when the mesh fails in ALE mesh update process by using Ansys MF solver.

ANSYS 9.0:Remesh in MF Solver


How to use

• Use FLDATA39 to setup the re-meshing parameters for fluid field in Multifieldsolver, no new MF commands required by re-meshing.

• FLDATA39, REMESH, Label, Value

ANSYS 9.0:Remesh in MF Solver


Example:Rigid body rotation of a valve in a tube


Electrostatic & Magnetic forces


Basis & advantagesThe theoretical basis for the projects is based on a new 3D electromagnetic formulation that uses analytic formulae for integral and post evaluations.

• General– + Reluctance forces due to material changes (not available currently)– + Current segment forces like electrodes (not available currently)– + Lorentz forces in permeable material (not available currently)– + Consistently combine these forces (there is confusion here now)– ! Yes, presently we can't do these forces; I think competition can't either

• Fast: • Accurate• Consistent

– Electric and magnetic methodology are the same– Easier usage, no prep7 action needed

• no need to create think air layer around body (present usage)• no more flagging (present usage)

– Users, at post1, select nodes on bodies of interes and call a FMGN to report forces– Compliant with present FMAGSUM: existing input continue to run


2-D ELECTROSTATIC FORCES

gVN

xWF r

t

20

argεε

=∂∂

=Simplified expression for combdrive driving force (ignores fringing effects [1,2]):

Electrostatic Force (N)

Driving (x) Transverse (y)

Simplified analytical [1,2] 5.31⋅10-9 0.0

ANSYS (Maxwell Stress Tensor)

3.55⋅10-9 0.006⋅10-9

ANSYS (New Virtual Work)

5.65⋅10-9 0.005⋅10-9

Potential distribution between comb fingers

Electrostatic forces developing between comb fingers

REFERENCES

1. T.-C. H. Nguyen W.C. Tang and R.T. Howe. Laterally driven polysilicon resonant microstructures. Sensors and Actuators A, 20:25–32, 1989.

2. M.W. Judy W.C. Tang, T.-C.H. Nguyen and R.T. Howe. Electrostatic-comb drive of lateral polysilicon resonators. Sensors and Actuators A, 21-23:328–331, 1990.


3-D ELECTROSTATIC FORCES

Potential distribution between two spherical electrodes

Electrostatic forces developing between two electrodes

REFERENCES

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capsph.html#c1

.

22

20

112

−

=∂∂

=

baa

VaWF r

aεπε

22

20

112

−

−=∂∂

=

bab

VbWF r

bεπε

Forces developing between two spherical electrodes:

Radial Electrostatic Force (N)

Fa (inner) Fb (outer)

Analytical model 2.23⋅10-6 -0.56⋅10-6

ANSYS (Maxwell Stress Tensor)

1.59⋅10-6 -0.79⋅10-6

ANSYS (New Virtual Work)

2.21⋅10-6 -0.55⋅10-6


3-D MAGNETIC FORCES: TEAM20 BENCHMARK

REFERENCES

1. M. Gyimesi, D. F. Ostergaard, “Analysis of Benchmark Problem TEAM20 with Various Formulations”, Proceedings of TEAM Workshop, COMPUMAG, Rio, 1997.

2. M. Gyimesi, D. F. Ostergaard, “Mixed Shape Non-Conforming Edge Elements”, IEEE Transactions on Magnetics, Vol. 35 No. 3, 1999, pp. 1407-1409.

3. M. Gyimesi, D. F. Ostergaard, “Non-Conforming Hexahedral Edge Elements for Magnetic Analysis”, IEEE Transactions on Magnetics, Vol 34 No. 5, 1998, pp. 2481-2484.

Vertical (z-direction) force (N)1000 A-turns 3000 A-turns 5000 A-turns

Experimental (target) 8.10 54.4 80.1

ANSYS (Old Virtual Work) 7.24 51.3 76.7

ANSYS (New Virtual Work) 7.25 51.4 76.8


High Frequency Electromagnetics


High-Frequency Electromagnetics

• Electromagnetic Wave Scattering from Periodic Structures and Frequency Selective Surface (FSS)

– Very difficult to simulate whole structure by FEA with HUGE number of DOFs

– Simplify the simulation using unit cell with Periodic Boundary Condition

Plane Wave

Periodic Structure

Master surfaceSlave surface



– Vector basis function with Floquet principle leads toEslave = Emastere-jΨ

– Hex, Tet, Wedge and Pyramid element– Coupling between master and slave surface– Plane wave excitation – Perfectly Matched Layers (PML) absorbing boundary

condition– Reflection/Transmission and radar cross section (RCS)

Calculation• Lumped Circuit Model in FEA Full-Wave Electromagnetic Solver

Microstrip line

FEA Mesh

Lumped circuit modelRLC



– Present the lumped circuit parameter in the high frequency electromagnetic distribution parameter system

– Integrate lumped RLC circuit model into full-wave electromagnetic FEA solver

– Hex, Tet, Wedge and Pyramid element

• Improve Fast Frequency Sweep Performance– Variation Technology (VT) for broadband Fast

Frequency Sweep– Speed up VT performance ~20% with the similar

memory requirement– PML termination with acceptable absorbing rate– Hex, Tet, Wedge and Pyramid element



• Special Absorption Rate (SAR) Calculation– Calculation of SAR in FEA element for lossy material– Plot/Print SAR distribution using ETABLE of ANSYS

postprocessor– Available in Hex, Tet, Wedge and Pyramid element

• Power Calculation of a N-port High-Frequency Electromagnetic System

– Input/Output power at ports– Dissipated power in N-port system– Power reflection/transmission coefficient, return loss

and insertion loss at ports


Thermoelectric Analysis


• Enhance the thermoelectric analysis to include (in addition to Joule heating) – Seebeck, Peltier, Thomson effects– transient electrical effects

Objectives


• New thermoelectric analysis option on the coupled-field elements– PLANE223, SOLID226, SOLID227– keyopt(1)=110

Electric field on Thermal field on Structural field off

• New material property to input Seebeck coefficients – MP,SBKX (also SBKY, SBKZ) - to model Seebeck and Peltier effects– MPDATA,SBKX (also SBKY, SBKZ) – to model Thomson effect

• Transient thermoelectric analysis now uses electric permittivity– MP,PERX (also PERY, PERZ) – to capture transient electrical effects

Scope


Elements - Summary

SF: CONV, HFLUX, RADBF: HGEN

Loads

3-D 10-node3-D 20-node2-D 8-nodeNameCoupled-field solid

SOLID227SOLID226PLANE223

0 - Plane1-Axisymmetric

KEYOPT(3)

KZZ, RSVZ, SBKZ, PERZ

KXX, KYY, RSVX, RSVY, SBKX, SBKY, DENS, C, ENTH, PERX, PERYMaterial

Properties

Temperature (TEMP) – Heat flow (HEAT)Electric scalar potential (VOLT) - Electric current (AMPS)

DOFs-Reactions

110 (thermoelectric analysis)KEYOPT(1)MP,PP,EDProduct

Geometry


• To do a thermoelectric analysis you need to– use one of these element types - PLANE223, SOLID226, SOLID227– set KEYOPT(1)=110– specify electrical resistivity (RSVX), thermal conductivity (KXX), and other

applicable properties (DENS,C,ENTH) if needed

• To include Seebeck/Peltier thermoelectric effects– specify Seebeck coefficients (SBKX)– specify the temperature offset from absolute zero to zero (TOFFST)– temporarily, you have to set KEYOPT(2)=1 to activate Seebeck/Peltier

coupling (in the final release, the coupling will be activated automatically upon the definition of Seebeck coefficients)

• To add electric transient effects – specify electrical permittivity (PERX)

Procedure


Example - Peltier Cooler

p-type material

n-type material

Iout

Iin= 10 A

conductor

Cold side T= -3 oC

Hot side T= -54 oC

Temperature distribution


• TECs are used in applications where temperature stabilization, temperature cycling, compact or pinpoint cooling are required:– Electronic and optical component cooling

• CPU, photodetectors, low noise amplifiers, laser diodes

– Consumer products• Portable food/beverage coolers, automotive seat cooling/heating

– Medical, laboratory and scientific equipment• Blood analyzers, thermal cycling devices (blood, lymph, DNA), heart and

eye surgery

– Military & Space• Naval navigation, night vision equipment, guidance systems

– Indoor environmental devices• Conditioners, fans, humidifiers

Markets and Applications


HEAT TRANSFER ENHACEMENTS –


Radiosity Solution Enhancements

Three major enhancements at ANSYS9.0(NOT available for FLOTRAN)-Posprocess radiation data via SURF251& SURF252 element types-Efficient solution for fine surface meshes

via decimation/agglomeration-Efficient solution for models with

symmetry planes


Decimation Concept

Radiation via coarse SURF251

Thermal via PLANE55

/SHRINK,.5 used for clarification


Radiation Enhancements

The following new commands allow generation of SURF251/252 elements:

RDEC : This specifies decimation parameters for coarsening

RSYM: allows user to define symmetry parameters

RSURF: action command to generate the surface elements

(Details in attachment command.doc)


Radiation Enhancements

Use the NMISC records of SURF251/252Elements to print /display the following:-area of each surface element-temperature of surface element-emissivity of surface element-enclosure # of surface element-net radiation heat flux leaving surface element(see attached input files for details)


Planer vs Cyclic Symmetry

POS(plane of symmetry) specified by user via CS command

COR(center of rotation) specified by user via CS command

1 reflection only

2 repetitions

original

original

Reflection is NOT the same as Repetition !!!


Planer Symmetry

SURF251

PLANE55

2 Planes of symmetry

Input file is RSYMtest1.dat


Cyclic Symmetry

Center of rotation

Cyclic symm plane

SURF251

PLANE55

Input file is RSYMtest2.dat

Documents

Solid Shell Element