INTERACTION EFFECT OF STRESS INTENSITY FACTORS FOR ANY NUMBER OF COLLINEAR INTERFACE CRACKS

In this study, the stress intensity factors for any number of interfac e cracks are calculated for various spacings, elastic constants and nu mber of cracks and the interaction effect of interface cracks is discu ssed. The problem is formulated as a system of singular integral equat ions on the basis of the body force method. In the numerical analysis, the unknown functions of the body force densities which satisfy the b oundary conditions are expressed by the products of fundamental densit y functions and power series. Here, the fundamental density functions are chosen to express the stress field due to a single interface crack exactly. The accuracy of the present analysis is verified by comparin g the present results with the results obtained by other researchers a nd examining the compliance with boundary conditions. The calculation shows that the present method gives rapidly converging numerical resul ts for those problems as well as ordinary crack problems in homogeneou s materials. The interaction effect of interface cracks appears in a s imilar way to ordinary collinear cracks having the same geometrical co ndition and the maximum stress intensity factor is shown to be linearl y related to the reciprocal of number of interface cracks.