Modal Analysis with Constraint Equations

[meshparts]

Hi all,

I want to do a modal analysis of a spindel nut system. If I define the connection between the nut and the saddle by a rotation displacement constraint equation, will this constraint be respected in the modal analysis? From the theory, I think it should, but I'm not sure...

Can anybody please tell me if this will work? Are there any issues, that I must take account of?

Thanx in advance!

Alex

 

[Drej]

Yes, it will be respected because it is a linear constraint (along with bonded contact and the like). Only linear model conditions are allowed in modal analysis (hence, non-linear contact - or a change in status of the model - non-linear geometry/materials are not permitted). If you are constraining using the CE command, run a static analysis first to make sure your assumption of the connection using CEs doesn't over-constrain or over-stiffen your structure.


------------
See faq569-1083 for details on how to make best use of Eng-Tips.com

 

[meshparts]

Thank you very much, Drej!