By default, the Abaqus Topology Optimization Module uses the data from the last load case, if any, and the last step of your Abaqus model to define the design response. Alternatively, if your model contains multiple steps and/or load conditions, you can select which step and/or load condition will be used to define the design response. In addition, if the design response is calculating an eigenfrequency, you can choose which mode or range of modes to examine.
To select the data source of a design response:
From the Create Design Response dialog box, select the Steps tabbed page.
Do either of the following:
Select Use last step and last load case to define the design response using data from the last step and/or last load case.
Select Specify to select the step and/or load condition that will be used to define the design response.
If you selected Specify, do the following to select a step or a load case (within a step).
Select 
to add a step to the list of design steps.
Select 
to add all of the valid steps to the list of steps.
Select 
to delete a step from the list of steps.
If the design response will calculate an eigenfrequency, you can select a mode or a range of modes from which the eigenfrequency will be calculated.
If the design region is a shell, you can select the location in the shell section from which the Abaqus Topology Optimization Module will calculate the shell stresses. You can choose from the following:
The value of the shell stress at the top, middle, or bottom layer of the shell. (The middle layer experiences no bending and behaves as a membrane.)
The maximum value of the shell stress from the top, middle, or bottom layer of the shell.
The minimum value of the shell stress from the top, middle, or bottom layer of the shell.
Select how the Abaqus Topology Optimization Module will extract the design response from the selected region. You can choose from the following:
The maximum value from the selected region.
The minimum value from the selected region.
The sum of the values from the selected region.
Select how the Abaqus Topology Optimization Module will extract the design response from the load cases. You can choose from the following:
The maximum value from all the selected load cases.
The minimum value from all the selected load cases.
The sum of the values from all of the selected load cases.
Click OK to save your data and to exit the editor.
