u/kokberg87

I have a steel beam with a concrete plate above it. The connection shall be ideal and the steel part is modeled as shells and the concrete as solid. To combine both, i used a tie constraint . To take account of the thickness of the shell, I defined the reference line at the top of the shell and placed the concrete plate directly on it. I expected the stresses ( material is equal for testing) on the top of the shell to be equal to the stresses at the bottom of the concrete but it is not. Where am I wrong and what is the correct way to model this situation?