A SIMPLE 4-NODED COROTATIONAL SHELL ELEMENT FOR ARBITRARILY LARGE ROTATIONS

A simple four-noded geometrically nonlinear shell element, which handl es arbitrarily large displacements and rotations, is presented in this paper. Based on the assumption of small incremental strain in each lo ad step, a corotational procedure is employed to extract the pure defo rmational displacements and rotations and update element stresses and internal force vectors through a piece-wise linearized strain-displace ment relation. To derive the tangent stiffness matrix, a three-dimensi onal degenerate, isoparametric shell model is employed. The 'locking' problem is alleviated by using mixed interpolation of tensorial transv erse shear strain components. The approach described in this paper is ideally suited for implementation in existing linear finite element pr ograms. A number of numerical examples are also presented.