Figure 1 Property Shell dialog box
•Thickness: Defines the thickness of shell element. In variable thickness element (shell4), this thickness is not applied. To see more information about setting the variable thickness, click here.
•Drilling Stiffness Factor: Defines the multiplier factor of drilling stiffness. If the drilling of shell element is too flexible, then the shell element can be changed stiffer for only drilling stiffness by enlarging the factor.