thin conducting plates

Suping

Dear Friends,

Gap elements are often used for modeling temperature jump due to heat flow across an imperfect contact. The problem is that it only simulates 1-D heat flow across the interface. This is not accurate for thin conducting plates where 3-D conduction can not be ignored. Generally, a thin plate has extremely high element aspect ratio, it is often treated as a ZERO thickness geometry object. My question is how to calculate/evaluate derivatives, say d (shape function)/dx, in the element stiffness matrix calculation.

Thanks!

Suping