RecurDyn F-Flex v1

Microsoft PowerPoint - RecurDyn F-Flex v1RecurDyn
RecurDyn/F-Flex

Part 2: RecurDyn/F-Flex
Import of the nodal flexible body
Edit functions for the nodal flexible body () Contact modeling in F-Flex
Post process in F-Flex
Flex loads
Part 3:

FEA
Model

Mat1materialMAT1Isotropic

SETComponentSETSet
FEA Elements RecurDyn Elements
MassEMass21CONM2Mass Element
RecurDyn
1.1 ANSYS Classical (
RecurDynANSYS

In 2D element, parabolic triangular type that has 6 nodes will be converted to linear element. In 3D element, parabolic pentagonal type that has 6 nodes will be converted to a linear element. In ANSYS, the constraint equation is converted to a rigid element where the base node is treated as a master node. RecurDynANSYS
Pyramid type elements are divided into two tetrahedral elements. ()
During the SET data converting, corresponding patch sets that include some or partial entities will be automatically generated. component setRecurDynpatch set
RecurDyn
©. 2006. All rights reserved
ANSYS CDWRITE CDB
MKS (kg,meter,second) : kg/m^3 : N/m^2, Pa
MMTS (Tone, mm, second), Ton,Kg : Ton/mm^3 : N/mm^2, MPa
mm
: ANSYS CDB
ANSYS Command cdwrite,db,block45,cdb,,,,blocked
:ANSYS CDWRITE CDB
1.2 DesignSpaceANSYS(*.inp)
ANSYS
RecurDyn
RecurDyn/NodalFlex toolkit (1)
A finite element model can be imported under Nastran or ANSYS formats.
The F.E. model can be generated from many mesh tools.
Beam, Shell(QUAD4 and TRIA3), and Solid(HEXA, TETRA, PENTA) elements are supported
and Linear and nonlinear material can be supported.
Rigid to Flex, Flex to Flex contacts are supported.
The surface of Solid and Shell element can be extracted as a flexible contact surface
and the curve of Beam element can be supported as a flexible contact curve easily.
A cross section of the flexible curve is circle.
The stress, strain and deformation contour can be supported as a post processor.
The data can be export for fatigue and life time analysis.
Other MBD force elements can be applied on specified nodes and elements.
System Level
RecurDyn/NodalFlex toolkit (2)
In Material, you can refer, generate and change a material parameters
such as Young’s modulus, density, Poisson's ratio and damping ratio.
In Property, a property of a element such as thickness of Shell can be changed and generated.
To modify a property of element or node easily,
you can define a set of elements or nodes with same characteristics.
Also, the contact surface can be defined from Patch Set.
A motion of node sets or nodes can be constrained by B.C.
Output such as displacement, velocity, acceleration, strain and stress
of a specified node can be plotted.
For convenient modeling work, you can change a ID of element or node. And, you also
create additional nodes. In Display, a specified element or node sets can be graphically inactive.
Edit Level
Post process in Nodal Flex
Simulation results for the Nodal Flexible Body are communicated by way of displaying color contours on the surface of the flexible body, and by graphing data in the Plot and Scope windows. The Contour option displays deformations, strains and stresses and includes a color legend that indicates the numeric range of the colors. The Contour option enables you to animate many kinds of outputs. The Plot and Scope options give nodal results in the form of curves on a graph, based upon a set of Output nodes defined in Body Edit Mode of the Nodal Flexible Body. The Plot and Scope options are valuable for interpreting various dynamic results.
Caution! Three animation files are generated for each Nodal Flexible Body in the model after a successful dynamic analysis. All the post- processing about flexible body is based upon these files. For the animation of the Nodal flexible body, these files should remain in the same working folder as the other RecurDyn model and output files. The name of animation files is composed with the names of each Nodal flexible body combined with the following file extensions: *.rfa: displacement animation data. *.erd: strain recovery data. *.srd: stress recovery data.
External loading Types
You can apply concentrated forces on specific node sets and pressure forces on specific element sets. Concentrated Loading In Uniform type, define nodal force or moment as Expression function. In Relative type, choose a reference node and define nodal force as Expression function.

RecurDyn

RecurDyn
12.20.2006 v1

ANSYS
Command: SHPP GUI: Main Menu| Preprocessor| Checking Ctrls| Shape Checking

The Aspect ratio is the ratio between the longest and shortest element edge. An extreme aspect ratio can produce and incorrect solution. Nodal Flex check that the aspect ratio falls within an acceptable range, as shown in table 5. The Solid4, Solid6 and Solid8 elements are governed by this rule.
RecurDyn
ELEMENT
SOLID26
SHELL4
Beam2
Beam2 is a general beam element with tension, compression, torsion, and bending capabilities. The element has six degrees of freedom at each node (translations in the nodal x, y, and z directions and rotations about the nodal x, y, and z axes). The element is defined by two nodes, the cross-sectional area and two area moments of inertia.
ANSYS: beam4ANSYS: beam4
Shell3
Shell3 is a triangular shell element with bending and membrane capabilities. The element has six degrees of freedom at each node (translations in the nodal x, y, and z directions and rotations about the nodal x, y, and z axes). The element is defined by three nodes and thickness.
ANSYS: shell63ANSYS: shell63
Shell4
If variable Thickness' button is not checked, it use thickness of Property Shell dialog box. Also, if change thickness, just change in this element. Other element's node thickness that
share changed node does not change.
If variable Thickness' button is not checked, it use thickness of Property Shell dialog box. Also, if change thickness, just change in this element. Other element's node thickness that
share changed node does not change.
Shell4 is a rectangular shell element with bending and membrane capabilities. The element has six degrees of freedom at each node (translations in the nodal x, y, and z directions and rotations about the nodal x, y, and z axes). The element is defined by four nodes and thickness.
Solid4
Solid4 is used for the 3-D modeling of solid structure. The element has three degree of freedom at each node (translations in the nodal x, y and z directions). The element is defined by 4 geometric corner nodes.
ANSYS: solid45ANSYS: solid45
Solid6
Solid6 is used for the 3-D modeling of a solid structure. The element has three degree of freedom at each node (translations in the nodal x, y and z directions). The element is defined by 6 geometric corner nodes.
ANSYS: solid45ANSYS: solid45
Solid8
Solid8 is used for the 3-D modeling of solid structure. The element has three degree of freedom at each node (translations in the nodal x, y and z directions). The element is defined by 8 geometric corner nodes.
Shell9
Shell9 is a rectangular shell element with bending and membrane capabilities. The element has six degrees of freedom at each node (translations in the nodal x, y, and z directions and rotations about the nodal x, y, and z axes). The element is defined by 4 corner nodes, 4 edge nodes, a face node, and thickness. Solid6 is used for the 3-D modeling of solid structure. The element has three degree of freedom at each node (translations in the nodal x, y and z directions). The element is defined by 6 geometric corner nodes.
Solid10
Solid10 is used for the 3-D modeling of solid structure. The element has three degree of freedom at each node (translations in the nodal x, y and z directions). The element is defined by 4 corner nodes and 6 edge nodes.
ANSYS RecurDyn
Solid26
Solid26 is used for the 3-D modeling of solid structure. The element has three degree of freedom at each node (translations in the nodal x, y and z directions). The element is defined by 8 corner nodes, 12 edge nodes, and 6 face nodes.
RecurDyn
Special Elements
These elements do not represent a feature of the structure but play a key rule in defining characteristic. For example, the constraints for each node and a specialized lumped mass can be defined. Rigid elements Rigid elements can be used to define
a constraint condition such as a fixed joint. Master node and slave nodes determine a constraint condition of the element. You can imagine that fixed joints connect the master node and all of the slave nodes. All the slave nodes degrees of freedom are rigidly linked with the master node and there is no limit on the number of slave nodes.
Mass Element Mass element can be used to represent a lumped mass. With the other
elements Nodal Flex uses a lumped mass concept for each node, so the inertia of nodes is ignored. However, all of the mass moment of inertia effects defined in the element property can be considered if you use a mass element. Using the element, a very stiff body that can be assumed as a rigid body will be considered efficiently.

RecurDyn
Import Set from ANSYS(1/6)
FE set can be imported. In addition a new Patch Set, which is grouped by the imported Set, is automatically made.
1. Create the FE body 2. Menu>Select>Component Manager…
1
2
3. Select the component set 4. In the example, I try to define the
Node Set and Element set
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4
4
5. Export the FE body using CDWRITE command 5
Import Set from ANSYS (3/6)
6. Import the FE body from *.cdb file
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7. Get into the Nodal Body Edit mode.7
You can see the ElemSet and NodeSet!! Also you can see the its Patch Sets!!
You can see the ElemSet and NodeSet!! Also you can see the its Patch Sets!!

RecurDyn
12-26-2006v1

L=1 m, W=.3 m, H=.2 m ,esize=.05

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RecurDyn F-Flex v1