Nonlinear finite-element method for plates and its application to dynamic response of reactor fuel subassemblies

Employing a convected coordinate system and triangular flat plate elements, a nonlinear finite-element procedure for transient analyses of structures is described. The displacement functions used in this procedure are linear for membrane and cubic for transverse deformations. Discretized equations of motion are integrated explicitly in time with a difference formula so that the need for the formulation of element stiffness matrix is eliminated. The elastoplastic problems are solved with linear isotropic strain hardening, von Mises yield condition, and a flow law derived from Drucker's postulate. Solutions for several problems, including that for LMFBR reactor fuel subassemblies, have been obtained by the present procedure and compared with experimental results. Agreements appear to be quite satisfactory. (Appl. Mech. Rev.)