Learning Forum

[Ji-Hyun Jeon]

Hello, everyone.

I want to apply repeated heat flux to the thin film and observe the deformation and increase in thermal stress. I think it is correct to turn on the large deflection effect because I want to continue the long analysis until the stress exceeds the UTS value. However, the solution continues to be interrupted due to an error in the deformation (such as the distortion is excessive or not converging). I already tried to make the mesh denser or to do a lot of time increment with the auto time stepping. I tried more elements than the captured mesh conditions, but it didn't work. (If I turn off the large deflection effect, it can be interpreted. Or, is it right to turn off the large deflection effect ? I'm curious about the criteria for judgment.)

My simulation conditions are as follows. The thin film (100*100mm^2) was modeled as a shell due to its thickness in nanometers. The material added NL physical properties (bilinear hardening) to the structural steel, which is the basic physical property provided. The four edges of thin film are fixed.

<- Transient structural analysis settings

[dlooman]

It's very hard to analyze thin films with large deflection on because the smallest amount of compression will cause them to buckle.  To at least get some initial results you could specify an elastic support over the surface and see if it allows you to get farther in the analysis.

[Ji-Hyun Jeon]

Thank you for your reply.

Then, do I usually have to turn off large deflection in thin film and interpret it?

[dlooman]

It would be a starting point at least.   

[Ji-Hyun Jeon]

Thank you.