Example: Defining the Eigenvalue

The task for this example is to define the Kreisselmaier-Steinhauser formulation for the first 5 eigenvalues of the first load case.

This task shows you how to:

Define in Tosca ANSA® environment

  1. Apply New > EIGENFREQUENCY on OBJ_FUNC_ITEM_1 or CONSTRAINTS item.

  2. In the LC_SET field enter a question mark "?".

  3. Click MORE 5 times and enter sub-steps 1 to 5 and click OK.

    This results in the following figure:

Define in Tosca Structure.gui

  1. Choose Command > DRESP.

    The DRESP menu appears.

  2. Define the Kreisselmaier-Steinhauser formulation as design response as shown in the following figure:

Define in Tosca Extension for ANSYS® Workbench

  1. Add a design response to the project, select Eigenfrequency as Category and DYN_FREQ_KREISSEL as Response Type.

  2. In order to select the desired five eigenfrequencies, select Manual as Load Case Selection, choose Modal as Analysis and set Step to 5.

    This results in the following figure:

SIMULIA Tosca Structure Parameter File

  • The resulting command in the parameter file look like follows: 

    DRESP
 ID_NAME    = freq_kreissel
 TYPE          = DYN_FREQ_KREISSEL
 DEF_TYPE       = SYSTEM
 LC_SET      = MODAL,ALL,1-5
 LC_SEL         = MIN
END_