One point quadrature shell element with through-thickness stretch

Abstract

A general purpose one point quadrature shell element accounting for through-thickness deformation is developed. In the shell. a complete 3-D constitutive law is introduced. leading to a 7-parameter theory which explicitly accounts for thickness change and also for a linear variation of thickness stretch. An interpolation scheme for the shell director is developed to avoid thickness locking. The developed shell element covers flexible warping behavior by using a local nodal coordinate system at each node. which is updated with second order accuracy. A physical stabilization scheme for zero energy modes is employed based on the decomposition of the strain field into constant and linear terms with respect to the natural coordinates. T-he rigid body projection is applied to treat rigid body rotations effectively. Linear and nonlinear patch tests including elasto-plasticity and contact are performed and the results are compared with analytical or previously reported results. ne results are also compared with those of 5-parameter shell elements. in order to show that there is no significant deterioration in accuracy. especially for thin shell applications. (C) 2004 Elsevier B.V. All rights reserved.