while simulating a large dia bellow I observed a very strange scenario.

Usually bending stiffness is left blank to get calculated by caesar -II ver 5.1 from given lateral stiffness finite length bellow & torsional stiffness left blank for torsionally rigid consideration of bellow.

However, putting these value to zero makes no difference at nearby anchor load with default value of bending & torsional stiffness. Loading & other parameter are absolutely same with zero stiffness compared to default value (essentially left blank).

This raises a question: does CAESAR-II consider zero stiffness values while we leave it blank?

Input incho too confirms it using zero value.
Pls help.confused about the matter.

Thanks,
Soumitra