Composite simulations in ANSYS WB 12

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Composite simulations in ANSYS WB 12


A: WB Simulation does not support direct definition of composite elements, such
as composite shells. However, one can add composite definition to surface
bodies in WB Simulation by performing the following steps:


1) A
dd a "Coordinate Systems" branch underneath the Model branch, if it does
not already exist.

Define a local Coordinate System that will define the
orientation of your shell element coordinate systems, if orthotropic/anisotropic
material definition is requi
red.

Note that the rules described in Section 2.3.1
"Element Coordinate Systems" of the ANSYS Elements Reference apply.


2) Under the Geometry branch, select the part(s) of interest, and in the Details
view, change the Coordinate System to the coordinate
system defined in step #1
above.

This will define the element x
-
, y
-
, and z
-
axes for orthotropic or
anisotropic materials.


3) Under the same parts, insert a "Commands" object.

In the Commands object,
the command syntax would like the following:

---

rdel
e,MATID

sectype,MATID,shell

secdata, <...>

---




The first command deletes

the real constant definition associated with the
part. MATID tells the program that it is to use the material associated with
the part. This line must be present.



The sec
ond defines

the shell section.
This line must be present.



One secdata line is to be defined for each lamellae.

The standard ANSYS commands for defining section definitions apply, so you
can define asmany SECDATA commands as required for each layer.

Note that if
you
have multiple materials, you may need to add "MP" commands in this
Commands object to define material IDs (e.g., material ID #2000), then reference
the material ID for a particular layer.

You can also use other section commands
like SECOFFSET and such, as

needed.


If you want to save output data for all layers, you can also add
"keyopt,MATID,8,1" or "keyopt,MATID,8,2", depending on whether you want to
exclude or include the midlayer output.


Solve the model, and the composite definition will be used.

Note
, however, that
postprocessing must be done in ANSYS General Postprocessor or via
"Commands" objects under the "Solution" branch in WB Simulation.

This is
because WB Simulation knows nothing of the composite definition, so the stress
output for surface bo
dies with composite definition will not be correct inside of
WB Simulation.


Further detailed information on ANSYS shell element capabilities and definition
can be found in Chapter 17

"Shell Analysis and Cross Sections" in the ANSYS
Structural Analysis Gu
ide.


Also, Chapter 13 "Composites" of the ANSYS Structural Analysis Guide is also
useful, especially if failure definitions are required.


Short example:


! Commands inserted into this file will be executed just after material definitions
in /PREP7.

!

The material number for this body is equal to the parameter "matid".


! Active UNIT system in Workbench when this object was created: Metric (mm,
kg, N, s, mV, mA)




rdele,MATID

sectype,MATID,shell

secdata, 1,MATID,0,3 !TK, MAT, THETA, NUMPT, Lay
erName

secdata, 1,MATID,0,3

secoffset,MID

seccontrol,0,0,0, 0, 1, 1, 1







!TK = Thickness of shell layer. Zero thickness (not valid for SHELL131 and
SHELL132) indicates a dropped layer. The sum of all layer thicknesses must be
greater than zero. The
total thickness can be tapered via the SECFUNCTION
command.

!MAT = Material ID for layer (any current
-
technology material model is available
for SHELL181, SOLID185 Layered Solid, SOLID186 Layered Solid, SOLSH190,
SHELL208, and SHELL209, including UserMat).

MAT is required for a composite
(multi
-
layered) laminate. For a homogeneous (single
-
layered) shell, the default is
the MAT command setting. Use the TREF and/or the MP, REFT commands to
address multiple reference temperatures.

!THETA = Angle (in degrees) o
f layer element coordinate system with respect to
element coordinate system (ESYS).

!NUMPT = Number of integration points in layer. The GUI permits 1, 3, 5, 7, or 9
points (default = 3). However a higher odd number may be specified in the
command. The inte
gration rule used is Simpson's Rule. (NUMPT is not used by
SHELL131 and SHELL132.)

!LayerName = The layer name (up to 72 characters) in an analysis using
FiberSIM data (SECTYPE,,SHELL, FIBERSIM). The layer name is case
-
sensitive and must match the ply name

in the FiberSIM .xml file. (In a non
-
FiberSIM analysis, this value serves only as a comment in the input.)