Learning Forum

[Panagiotis]

I am trying to perform Direct Optimization into a model created with APDL. Specifically, I enter the input file into the Analysis of the Mechanical APDL subsystem. However, the problem is that when I perform direct optimization, I want to apply specific relations onto the parameters defined at the parameter set.

Giving an example where a=number of stiffeners on a panel, b= web thickness

The relation I want to apply is: if a=0 then b=0 . so that Design Points generated have actual geometric meaning. (if there are no stiffeners on the plate their thickness must be zero)

 

[John Doyle]

I think this can be done.  Please refer to Workbench User's Guide=> Working with Parameters=> Expressions, Functions, Quantities, and Units...

Why do you have to set b=zero?  Won't that just cause problems during geometry creation (i.e. how do you build a gusset with zero thickness)?  Wouldn't it be better to just skip building gussets whenever a= zero?

[Panagiotis]

 

I found the relative referrence in the WB user’s guide but I do not think it includes the problem I have, as I do not see the option to use conditional statements.

Regarding your comment let me explain:

The APDL script I have developped does not build stiffeners when a=0. However, as I am using MOGA to perform structural optimization, the algorithm sets a=0 and b<>0 which does not make sense. As you probably know, I do not have control over the values MOGA sets in order to perform the optimization and the APDL script I have created performs structural analysis of a given stiffened panel. My concern is that this discrepancy misleads the optimization algorithm from finding the correct optimal design point. Can you please advise on how this problem should be handled?