An effective finite rotation formulation for geometrical non-linear shell structures

This paper presents a simple stress resultant 4-node shell element for geom etrical non-linear analysis. In order to model smooth surfaces and/or stiff ened structures, a simple and efficient technique for finite rotation is ad opted. By means of suppressing the component of singular rotation effectivl ey, convenient use of six degrees of freedom is possible without deteriorat ing the robustness and the convergence rate of the classical 5-dof formulat ion. In the formulation of shell element, section eccentricity is also cons idered to model stiffened structures. Through numerical experiments the eff ectiveness of the proposed method is demonstrated.