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Subcase-specific modeling is currently only available for linear analyses (2021 OptiStruct help). What is the roadmap for the implementation of the nonlinear and contact analyses?
hi @oldninja
can you be a little bit more specific on what do you need?
For NL there is MODCHANGE that covers a little bit these model changes from one case to another.
But it would be helpful if you describe some use cases too.
Hi @Adriano A. Koga,
Sure. We have a model with contact between parts and we are interested in performing some geometrical changes as well as some mesh refinements without the need to re-run the entire model due to its size. SUBMODEL, SID, SID_r<br />or<br />GLOBSUB, SUBID, SID
SUBMODEL, SID, SID_r<br />or<br />
Are limited for the linear analyses, and we are interested in nonlinear with contact support. I read in a previous post (from a couple of years ago) that the development team was working on implementing these for other analysis types, so that is why I am asking for the roadmap to implementation.
I just searched for MODCHANGE in the OptiStruct documentation, so maybe let's add a request for documentation of that option if possible.
Thanks!
Hi @Adriano A. Koga, Sure. We have a model with contact between parts and we are interested in performing some geometrical changes as well as some mesh refinements without the need to re-run the entire model due to its size. SUBMODEL, SID, SID_r<br />or<br />GLOBSUB, SUBID, SID Are limited for the linear analyses, and we are interested in nonlinear with contact support. I read in a previous post (from a couple of years ago) that the development team was working on implementing these for other analysis types, so that is why I am asking for the roadmap to implementation. I just searched for MODCHANGE in the OptiStruct documentation, so maybe let's add a request for documentation of that option if possible. Thanks!
sorry..my bad. It is MODCHG for changing NL models;
have you tried the newer submodel techniques?
I've tried myself creating a submodel from a lerger NL run, and it was fine.
I've never used NL to NL, but I believe it works too, as long as your local model doesn't affect too much your global stiffness.
https://community.altair.com/community?id=community_blog&sys_id=f3ba978ddbe86050e8863978f4961968
Bulk Data EntryDefines parameters for removing and/or reactivating contact interfaces and/or elements.
sorry..my bad. It is MODCHG for changing NL models; have you tried the newer submodel techniques? I've tried myself creating a submodel from a lerger NL run, and it was fine. I've never used NL to NL, but I believe it works too, as long as your local model doesn't affect too much your global stiffness. https://community.altair.com/community?id=community_blog&sys_id=f3ba978ddbe86050e8863978f4961968 MODCHG Bulk Data EntryDefines parameters for removing and/or reactivating contact interfaces and/or elements.
Thanks, I will look at MODCHG to see if it works for our purpose.
I haven't tested the newer submodel techniques. I read the manual, and it says that it is restricted to linear analyses; that's where I stopped. I looked at that beam model in the blog, but I have a more complex situation, but it certainly illustrates the option.
What would be the workflow or a sample procedure using the MODCHG and SUBMODEL? Nonlinear and contact case.
Can I for example perform the global analysis with contact and nonlinearities and then perform the submodel as a linear case?
Thanks, I will look at MODCHG to see if it works for our purpose. I haven't tested the newer submodel techniques. I read the manual, and it says that it is restricted to linear analyses; that's where I stopped. I looked at that beam model in the blog, but I have a more complex situation, but it certainly illustrates the option. What would be the workflow or a sample procedure using the MODCHG and SUBMODEL? Nonlinear and contact case. Can I for example perform the global analysis with contact and nonlinearities and then perform the submodel as a linear case?
yes, you can perform NL global, and linear submodel.
I just did this to a submodel for a project. Of course, my submodel was built in a non-contacting area.
