Improvement of a 3-node triangular shell finite element using strain smoothing technique

Abstract

Shell structures have been widely used in various engineering fields and the Finite Element Method (FEM) has been powerfully used for analyzing these shell structures over the past several decades. Among the various shell finite elements, the triangular shell finite elements are advantageous for automatic mesh generations of shell structures with complex shapes. Even recently a new 3-node triangular shell finite element named MITC3+ has been developed that gives as accurate results as the state-of-the-art 4-node quadrilateral shell finite element. The MITC3+ shell finite element solves the locking phenomenon very successfully and thus has an outstanding convergence behavior in bending-dominated problems. However, there is no difference in membrane performance from the 3-node triangular displacement-based shell finite element (DISP3). In this study, a new 3-node triangular shell finite element named MITC3+S which improves the membrane performance of the MITC3+ shell finite element is proposed and there are two versions. The first version of the MITC3+S shell finite element has contributed to the successful application of the edge-based strain smoothing technique to the continuum mechanics based MITC3+ shell finite element. The first version has successfully improved the membrane performance of the MITC3+ shell finite element. The second version of the MITC3+S shell finite element alleviates the problem of increasing computation time in the first version with an enhanced edge-based strain smoothing technique. The second version has even better membrane performance than the first version.