The simplified MITC4+ shell element and its performance in linear and nonlinear analysis

Abstract

The recently developed improved MITC4+ shell element exhibits excellent convergence behavior in both bending- and membrane-dominated shell problems. Compared to the widely recognized MITC4 shell element, the membrane and in-plane shear locking were significantly alleviated. However, it is difficult to implement the assumed membrane strain field because of its complexity. In this study, a simplified MITC4+ shell element is developed. A simpler assumed membrane strain field that facilitates the extension to nonlinear formulations is proposed. To reduce the sensitivity of the element performance to mesh distortion, a geometry-dependent Gauss integration scheme is employed. The proposed element passes the patch, zero-energy mode, and isotropy tests. The performance of the simplified MITC4+ shell element is demonstrated using various linear and nonlinear benchmark problems.