An Edge-Based Smoothed MITC3 (ES-MITC3) Shell Finite Element in Laminated Composite Shell Structures Analysis

This paper proposes an improvement of the MITC3 shell finite element to analyze of laminated composite shell structures. In order to enhance the accuracy and convergence of MITC3 element, an edge-based smoothed finite element method (ES-FEM) is applied to the derivation of the membrane, bending and shear stiffness terms of the MITC3 element, named ES-MICT3. In the ES-FEM, the smoothed strain is calculated in the domain that constructed by two adjacent MITC3 triangular elements sharing an edge. On a curved geometry of shell models, two adjacent MITC3 triangular elements may not be placed on the same plane. In this case, the edge-based smoothed strain can be performed on the virtual plane based on strain transformation matrices between the global coordinate and this virtual coordinate. Furthermore, a simple modification coefficient is chosen to be 10(-3) times the maximum diagonal value of the element stiffness matrix at the zero drilling degree of freedom to avoid the drill rotation locking when all elements meeting at a node are coplanar. The numerical examples demonstrated that the proposed method achieves the high accuracy in comparison to others existing elements in the literature.