THERMAL-STRESS INTENSITY FACTORS FOR A CRACK IN A STRIP OF A FUNCTIONALLY GRADIENT MATERIAL

A crack in a strip of Functionally Gradient Material mathematically modeled by a nonhomogeneous solid with the prescribed surface temperature is studied. The crack faces are supposed to be completely insulated. It is assumed that all material properties depend only on the coordinate y (perpendicular to the crack faces) in such a way that the properties are some exponential functions of y. By using the Fourier transform, the thermal and mechanical problems are reduced to two systems of singular integral equations, respectively, which are solved numerically. The results show that by selecting the material constants appropriately, the stress intensity factors can be lowered substantially. The crack close to the cooling side of the strip will be more likely to be stable than that close to the heating surface.