Static bending analysis of functionally graded sandwich spherical shells using an edge-based smoothed finite element method

This study investigates the static bending behavior of Functionally Graded (FG) sandwich spherical shells using a triangular shell element that integrates the Edge-based Smoothed Finite Element Method (ES-FEM) with the Mixed Interpolation of Tensorial Components technique (MITCi), referred to as the ES-MITC3i approach. In this approach, the stiffness matrix is formulated based on a strain smoothing technique, where the smoothing domains are established by grouping neighboring MITC3i triangular elements that share common edges. The strain smoothing process enhances both the accuracy and convergence rate compared to the conventional MITC3i formulation. The material characteristics of the FG shells are assumed to follow a power-law distribution of constituent volume fractions through the shell thickness. Numerical simulations confirm that the ES-MITC3i approach effectively avoids shear locking and delivers highly accurate results when compared with benchmark solutions reported in existing literature.