AN EFFICIENT 4-NODE 24-DOF THICK SHELL FINITE-ELEMENT WITH 5-POINT QUADRATURE

A 4-node flat shell quadrilateral finite element with 6 degrees of fre edom per node, denoted QC5D-SA, is presented. The element is an assemb ly of a modification of the drilling degree of freedom membrane presen ted by Ibrahimbegovic ct al., and the assumed strain plate element pre sented by Bathe and Dvorkin. The part of the stiffness matrix associat ed with in-plane displacements and rotations is integrated over the el ement domain by a modified 5-point reduced integration scheme, resulti ng in greater efficiency without the sacrifice of rank sufficiency. Th e scheme produces a soft higher order deformation mode which increases numerical accuracy. A large number of standard benchmark problems are analyzed. Some examples show that the effectiveness of a previously p roposed ''membrane locking correction'' technique is significantly red uced when employing distorted elements. However, the element is shown to be generally accurate and in many cases superior to existing elemen ts.