Material Optimization Using Optistruct

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hello everyone,

 

I have been conducting some tasks which use an iterative approach to correlating CAE results to physical testing. We attempt to match the modal behavior of modeled parts to the real thing, and I believe the process can go much faster (and more accurately) if we incorporated some optimization techniques into the process. Our goal is to determine the correct modulus for the material, and while it generally takes 1-2 iterations to get it right when tweaking the cards by hand, I'd still like to set up a general optimization template to do it automatically.

 

Now, I'd be able to do this sort of thing in LS-Opt, where all that would be required is a simple replacement of the modulus and density of the material with some generalized parameters; then you could just apply upper/lower bounds to each parameter and have LS-Opt check the normal modes after each iteration, and compare them to experimentally determined values until a good correlation was achieved. The problem, however, is at my current company, we don't have LS-Dyna (or Opt), and I have no idea if Optistruct is capable of this type of optimization (I've used it for topology and sizing in the past, but never for material modeling).

 

Specifically this is what I would like to do with the optimization loop.

 

1. Parameterize the elastic modulus of a material card. (Example: Modulus of 116500 MPa becomes some parameter <E>)

2. Impose upper and lower bounds on that modulus: ( 90000 MPa < E < 120000 MPa)

3. Run a normal mode optimization (preferably without mode tracking, as our physical testing rig only looks for out-of-plane modes and will skip other resonant modes), which looks for certain frequencies and attempts to match a frequency range by varying the modulus.

4. Run until some confidence has been achieved for the material.

 

Any idea about how I could go about doing this? Thanks for your time.

 

-George

Answers