CRACK-CLOSURE EFFECTS ON A PARTIALLY INSULATED CRACK IN A FUNCTIONALLY GRADED MEDIUM UNDER THERMAL LOADING

摘要

In this paper, we consider an infinite functionally graded medium with a partially insulated crack subjected to a steady-state heat flux away from the crack region. The material is modeled as a nonhomogeneous isotropic elastic medium. The problem is solved under the assumption of plane elasticity. The equations of heat conduction and elasticity are converted analytically into singular integral equations which are solved numerically to yield the crack tip stress intensity factors under thermal loading. A crack-closure algorithm is developed to handle the problem of having negative mode I stress intensity factors. The main objective of the paper is to study the effect of the material nonhomogeneity parameters and crack-closure effects on the crack tip stress intensity factors for the purpose of gaining better understanding of the behavior of graded materials.