Analysis of a Crack Propagating Along the Gradient in Functionally Gradient Materials with Exponential Property Gradation

지수형적 물성변화를 갖는 함수구배 재료에서 구배방향을 따라 전파하는 균열 해석

Stress and displacement fields for a propagating crack in a functionally gradient material (FGM) which has exponentially varying elastic and physical properties along the direction of the crack propagation, are derived. The equations of motion in nonhomogeneous material are developed using displacement potentials. The solutions to the displacement fields and the stress fields for a crack propagating at constant speed along the gradient are obtained through an asymptotic analysis. The influences of nonhomogeneity on the higher order terms of the stress fields are explicitly brought out. Using these stress components, isochromatic fringes around the stationary crack are generated at crack for different nonhomogeneity and the effects of nohonhomgeneity on these fringes are discussed.