(A) 4-node non-conforming shell element with drilling degree of freedom

Abstract

In this paper, a versatile shell element with drilling degree of freedom has been developed by modified flat shell approach. This element is made basically by combining a membrane element with drilling degrees of freedom and a plate bending element. And the effect of out of plane warp is considered by rigid link correction. This element possesses six degree of freedom per node which permits an easy connection to other types of finite elements and improves the element behavior as well. In plate bending part, an improved Mindlin plate has been established by the combined use of the addition of non-conforming modes, the reduced (or selective) integration scheme, and the construction of the substitute shear strain fields. In membrane part, the non-conforming displacement modes are added to the displacement fields to improve the basic behavior of membrane element with drilling degree of freedom. The shell element proposed herein passes the patch tests, does not show any spurious mechanism and does not produce shear and membrane locking phenomena. This element yields reliable solutions even for the distorted meshes through the analyses of benchmark problems.