Jim Day
Ansys Employee
Short answer is that it's OK for shells and solids to share nodes. The rotational DOF of the nodes aren't used by the solid elements. Since this entails having nodes on the inner surface of the shells, use NLOC in *SECTION_SHELL accordingly and set CNTCO in *CONTROL_SHELL so that the contact recognizes the offset of the shell given by NLOC. To avoid uncertainty of how contact stiffness is calculated in this shared node situation, I'd just use SOFT=1 or SOFT=2.