How to set up a model including superelement in OptiStruct

Question

In tutorial there is an example to generate superelemnent in linear static analysis.

But I need to do modal analysis using superelement. I hope very much if someone in this field can give me a step-by-step manual I can follow. Thanks!

Altair Forum User · Answer

Hi Rahul, I have finished the demo you offered me in hypermesh12.0 using Static Condensation and  Craig-Bampton method !  But interestingly,if I use hypermesh13.0 to run the same file,it failed and said 'Control cards 'METHOD=n' are not allowed u when CMSMETH card is present.' .I have sent you the file in dropbox which I defined the control card using hm12.0, Can you please check it out using hm13.0?? Thanks a lot! And I have an another question,the demo you gave me only had two parts.If there are three parts (See figure attached).I want to define part A and B as external superelements and  part C as residual structure. How can I do it ? Should I define  the node set 1 and 2 in  superelement A, and node set 1 and 3 in superelement B as ASET??<?xml version="1.0" encoding="UTF-8"?>

Altair Forum User · Answer

Thank you very much for your referrence file.  It's simlimar to  the procedure using CMSMETH  in Linear Static.

But when I imported cantilever_cms.fem  and run optistruct in hw13.0(I've check the card but didn't change anything ), It failed and said  Card 'METHOD(STRUCTURE)' is not allowed for this subcase type. What's wrong with it. I'm trying to solve the problem.

Rahul Rajan_21763 · Answer

Hi,

Please find attached deck and doc for modal analysis using superelement.Please go through that and let us know your feedback.

Regards

Rahul R

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Dynamic_Reduction_CMS_SE.pdf