multiple thickness shells

Hi,

You need to use 'variable' in the shell pair definition

As there can be no common mid-surface you need to define where the mid-surface is. Note 'select placement surface'. This is an approximation and actual mid-surfaces will be moved so that they align. This will change the stiffness of the structure.

The process works in a similar way if your plates are a single part or an assy of two plates.

When you mesh, switch off 'display shells with zero thickness' and you will see what the numerical model will be ...

Regards