A 24 DOF 4-NODE FLAT SHELL FINITE-ELEMENT FOR GENERAL UNSYMMETRIC ORTHOTROPIC LAYERED COMPOSITES

The constitutive relationship of a four-node flat shell finite element with six degrees of freedom per node and a modified five-point quadra ture, previously presented by the authors, is extended to include symm etric and unsymmetric orthotropy. Through manipulation of the kinemati c assumptions, provision is made for out-of-plane warp. A wide range o f membrane and thin to moderately thick plate and shell examples are u sed to demonstrate the accuracy and robustness of the resulting elemen t.