Large Compliance Problems

Alex Nguyen

Hi everyone, I am a newbie. I'm working with respect to Static Linear and Buckling Linear.

I have a problem with my model when I run OptiStruct. Those are errors about  'Large Compliance', although I created constraints SPC for model. 

Please check my .out file attached and help me.

Thank you very much /emoticons/default_smile.png' srcset='/emoticons/smile@2x.png 2x' title=':)' width='20' />

<?xml version="1.0" encoding="UTF-8"?>

Unable to find an attachment - read this blog

Rahul Rajan_21763

Looks like there are modelling issues. Either nodes are not connected (free edges) or loads and BCs are not applied properly.

Alex Nguyen

Dear Mr. Rahul R

Thank you for your answer. I attached figure of constraint position. These are two overlapped plates. In fact, these two places connect together by welding. So I used MPC to connect these plates and I create SPC on end of plate's hole (square hole). In this model,  load is only GRAV. Whether something's wrong in my constraints (SPC on nodes) or not? 

I'm be grateful your helping.

Best Regards

<?xml version="1.0" encoding="UTF-8"?>

Rahul Rajan_21763

I guess this could be because of mpc independent node constraints because all the dofs in the equations are already spced are defined as slaves in other equations.

tinh

Do you mean MPC is created by panel Analysis>equations?

I wonder why you use that MPC?

and what is your MPC setting (which dofs, how weight is it?)

 

large compliance is a signal of insufficient constraint, I think the MPCs did not fix RBM (not enough dof)

 

Using RBE2 to weld them more easily.

Alex Nguyen

Yes, I'm very thank you. Maybe I mistaked about MPC.

Best regards