Thermo-elasto-plastic stresses in functionally graded materials subjected to thermal loading taking residual stresses of the fabrication process intoconsideration

Functionally graded materials (FGMs) have recently been received with consi derable interest, primarily as high temperature resistant materials for spa ce vehicles subjected to high temperature environment. FGMs are one of the composite materials and consist of continuous change of composition of diff erent material components from one surface to the other. FGMs usually fabri cated at high temperature at which the FGMs have stress free condition. Aft er the FGMs cooled from the fabrication temperature to the room temperature residual thermal stresses produced. In this paper, elasto-plastic thermal stresses in a rectangular plate (FGP) of a particle reinforced composite FG M are treated by finite element method due to the microscopic combination l aw when the FGP is subjected to three kinds of temperature conditions, firs t is cooling from the fabricated temperature to the room temperature, secon d is heating and last is heating after cooling from the fabricated temperat ure. In the analysis, the thermal stress constitutive equation of a particl e-reinforced composite taking temperature change and damage process into co nsideration is used. The effects of the particle volume fraction and the th ree kinds of temperature conditions on the stresses in the matrix, stresses in the particle and macroscopic stress are discussed. (C) 2001 Elsevier Sc ience Ltd. All rights reserved.