Thermomechanical Elastic–Plastic Stability and Failure Analysis of FGM Plate

Abstract

A mathematical model based on the first-order shear deformation theory and the von Karman’s nonlinear kinematics for buckling, postbuckling and failure analysis of elastic–plastic Functionally Graded Material (FGM) plate under thermomechanical is presented. The FGM plate with continuously varying properties along thickness is modeled as a laminate composed of multiple perfectly-bonded layers made of isotropic and homogeneous material having layer-wise constant composition. The thermoelastic properties of FGM are calculated using rule of mixtures and Tamura-Tomota-Ozawa model (TTO model). Whereas, the elastic–plastic material properties are evaluated in accordance with the TTO model, assuming the ceramic phase of FGM to be elastic and the metal phase to be elastic–plastic. Further, the elastic–plastic analysis of FGM is assumed to follow J2-plasticity with isotropic hardening. Parametric studies are conducted to investigate the effects of plasticity, material inhomogeneity, and thermomechanical loading conditions on the elastic–plastic buckling, postbuckling behavior, and the ultimate load capacity of FGM plate. The postbuckling response of FGM plate is found to be greatly affected by the plasticity consideration. FGM plate with elastic material properties exhibited a continuous increase in the postbuckling strength; whereas, the postbuckling strength of an elastic–plastic FGM plate decreases initially and finally, ultimate failure of the plate occurs.