Hi all:

I have recently purchased SW2011 and it's running great. I am running some thermal stress simulation in a wirebonding model. Since the linear analysis shows

the wire is passing the yield stress and the wire is encaped by slicione rubber, nonlinear thermal stress analysis is required.

In the linear analysis, I constrain the model by using the option" use soft spring to stabilize the model" but I cannot find the same opinion in the nonlinear interface.

Is there some similiar opinion to stabilize the model or there are some ways to constains the model with out introducing big stiffness matrix singularity?

Many thanks.

Zhemin

From what you show I would use sliding constraint on the side face, place two constraints at location on mutually perpendicular to each other and the side face and then place another "vertical" constraint a location two. Then run a linear analysis without soft springs.

If it will not run, consider checking that everything is bonded properly as this is an assembly analysis.

You can check for unbonded components by putting a fixed constraint or a small force on them one by one or looking to see if there is a separation when you use soft springs.