Effect of temperature on the dynamic crack-tip stress fields in graded material

The stress- fields near the crack tip for mode-l thermo-mechanical loading in functionally graded material (FGM) are developed using displacement potentials in conjugation with an asymptotic approach. The shear modulus, mass density and coefficient of thermal expansion of the FGM are assumed to vary exponentially along the gradation direction. Using insulated crack face boundary condition and steady state heat conduction assumption, the temperature filed near to the crack tip is developed. By incorporating the developed temperature field equations, asymptotic thermo-mechanical stress field equations are derived. The superposition of the temperature stress field with the mechanical stress field results in imposing normal stress on traction free crack faces. A stress field which has opposite traction forces on the crack face line is added to satisfy the mode-l crack propagation crack face boundary condition. Using the derived stress fields, contours of constant maximum shear stress are generated and the effect of temperature on these contours is discussed. © 2008 Society for Experimental Mechanics Inc