Learning Forum

[piotrkurgan]

Hi everyone,

I am trying to perform a simple coupled EM-thermal-structural analysis using WorkBench 19v2. The structure under analysis is a simple microstrip line (a copper 1.7mm strip placed on a dielectric substrate - Taconic RF-35 - with a copper ground plane metallization on the other side of the substrate). 

1. EM analysis returns standard results. Material parameters (copper & Taconic RF-35) are loaded from the library - I also enable options including parameters needed for thermal and structural analyses. 

2. The results of EM analysis are transfered to steady-state thermal system and imported in the form of a heat flux (selecting all faces or only microstrip line faces lead to similar results). For Convection, all faces of the structure are selected as well. The temperature distribution generated by steady-state thermal system looks reasonable (temperature concentrates in the microstrip and dissipates in the dielectric). For a 1W excitation of the microstrip, we are dealing with max 23 celcius degrees. 

3. Transfering these results to a static structural system leads to deformations larger than model bounding box. Both body temperature from thermal analysis and body force density from EM analysis are imported here. I also add fixed suport, selecting front and back faces of the substrate, as otherwise the analysis failes with an error "solver pivot warnings or errors have been encountered during the solution".

I tried different combinations of meshes and boundary conditions, but the results is always similar.

Do you have any suggestions what might be the problem?  

[Sandeep Medikonda]

In a structural simulation, a model needs to be properly constrained. Please try the troubleshooting techniques listed in this post.

If that doesn't help, screenshots will often help us better understand the issue.