heat transfer with solid mechanics problem

I build a model with heat transfer in solids and solid mechanics, heating from the bottom of the model by adding a high temperature. There's a boundary load set on the top side.
To simplify the question, I add symmetry to both heat transfer and solid physics ,and set a fixed constraint of the center point.
The average element quality of the mesh is around 0.65. In the time dependent case, the study is really hard to converge and the progress graphics is almost divergent.
I was wondering if there would be any constraints I could add to the model.
Thanks!