Mechanical APDL Basic Analysis Guide

Editing data typically falls into two general categories: changing data within an existing material property,
and copying an entire material property set to form another model with slightly different properties.

Consider a case where you need to change the constants that you assigned to the Nonlinear Isotropic
model. To perform this task:

1. Double-click on Nonlinear Isotropic. The associated dialog box appears with the existing data displayed
   in the fields.


2. Edit the constants in the appropriate fields, and click on OK.

Note that if you needed to change any of the other material properties, you would double-click on

Linear Isotropic in the previous step. This would cause the dialog box associated with linear iso-

tropic properties to appear. You could then edit those properties.

Consider another case where you have the requirement for two material models, where the second
model is the same as the first except that it needs to include constants for one more temperature. To
perform this task:

1. In the Define Material Model Behavior dialog box, click on the following menu path:Edit> Copy, then
   choose 1 for from Material number, and enter 2 for to Material number. Click on OK. The Material
   Models Defined window now includes Material Model Number 2 in its list. If you double-click on Ma-
   terial Model Number 2, the identical material properties appear below Material Model Number 2 as
   those listed for Material Model Number 1.


2. Double-click on Nonlinear Isotropic under Material Model Number 2. The associated dialog box appears.


3. Move the text cursor to the Temperature row in the column furthest to the right, and click on the Add
   Temperature button. A T3 column appears.


4. In the new column, enter the new temperature and the four constants associated with this temperature.


5. Click on OK. The dialog box closes. If you double-click on Nonlinear Isotropic under Material Model
   Number 2, the associated dialog box appears and reflects the new temperature data that you added for
   Material Model Number 2.

1.1.4.4.7. Example: Defining a Material Model Combination

This example is intended to show you how to define a material based on a combination of two mater-
ial models. It steps you through a procedure that uses the material model interface to define a material
for simulating cyclic softening at one temperature. This is accomplished by using the Nonlinear Isotropic
model combined with the Chaboche model.

If you performed either of the previous examples in this section, start a new session before beginning
the following example.

1. From the Main Menu, click on the following menu path:Preprocessor> Material Props> Material
   Models. The Define Material Model Behavior dialog box appears.


2. In the Material Models Available window, double-click on the following options:Structural,Linear,
   Elastic,Isotropic. A dialog box appears.


3. Enter values for material properties, as required (EX for elastic modulus, and PRXY for Poisson's ratio).
   Click on OK.Material Model Number 1 and Linear Isotropic appear in the Material Models Defined
   window.

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