Shell element of relative degree of freedom and its application on buckling analysis of thin-walled structures

Shell element of relative degrees of freedom (SERDF) is a special transformation of solid element. It can be used in finite element (FE) analysis of both thin and thick shell structures and the formulation is simpler than normal shell elements. Introduction of additional internal degrees of freedom will improve the calculation precision. mulation of SERDF in the buckling analysis is derived in this article. Different measures of tackling additional internal degrees of freedom for different kinds of buckling problems and different stages of numerical analysis are presented. Some numerical examples are given to illustrate the validity of this element and the method.