Analysis of functionally graded porous plates using an enhanced MITC3+ element with in-plane strain correction

In this work, an enhanced MITC3+ approach enriched by a constant in-plane strain correction is proposed in the analysis of functionally graded (FG) porous plates. The approach involves formulating the corrected in-plane strain field through the utilization of corrected nodal derivatives in the concept of discrete divergence consistency (DDC). The DDC for the in-plane strain field is obtained through the orthogonality condition derived from the three-field variational principle (Hu-Washizu), which arises from the difference between resultant in-plane stress and in-plane strain. In carefully examining the static analysis of the FG porous plate with different elements, our investigation delves into the influence of length-to-thickness ratios, power-law indices, and porosity distributions. This comprehensive examination aims to illuminate their combined influence on the numerical outcomes. The proposed approach demonstrates superior performance in addressing FG shell problems, outperforming the original MITC3+ method.