Thermoelastic buckling analysis of plates and shells of temperature and porosity dependent functionally graded materials

Abstract

This study aims to explore for the first time the thermoelastic buckling behavior of functionally graded porous plates and shells using an efficient finite element model based on the first-order shear deformation theory (FSDT) with the improvement of the shear strains via the introduction of a quadratic function that able to take into account the parabolic distribution of transverse shear stresses without any need of shear correction factors as standard (FSDT) theory. In this research, different sets of functionally graded metal/ceramic combinations, as well as porosity distributions, namely uniform (or even) and random (or uneven) porosity patterns, are also considered, and the effective material properties of the graded porous structure are determined via a modified power-law function. Two types of applied thermal loads are considered, namely Uniform and nonuniform thermal load (UT, NUT) with temperature-dependent (TD) and independent (TID) mechanical properties. The Green-Lagrange formulation, variational method, and a numerical iterative algorithm are applied to solve the governing equations with porosity and thermal dependent coefficients. To verify our results, various numerical comparisons are conducted on critical temperature buckling of plates and spherical shells, and they are compared with available results where a close correlation is observed. The influence of thermal loads, porosity volume fraction, types of porosity patterns, temperature dependency, and geometrical aspects on the thermal buckling behavior of FG porous plates and shells are scrutinized through different parametric studies.