Stress intensity factors around a cylindrical crack in an interfacial zone in composite materials

Axisymmetric stresses around a cylindrical crack in an interfacial cylindrical layer between an in_nite elastic medium with a cylindrical cavity and a circular elastic cylinder made of another material have been determined[ The material constants of the layer vary continuously from those of the in_nite medium to those of the cylinder[ Tension surrounding the cylinder and perpendicular to the axis of the cylinder is applied to the composite materials[ To solve this problem\ the interfacial layer is divided into several layers with di}erent material properties[ The boundary conditions are reduced to dual integral equations[ The di}erences in the crack faces are expanded in a series so as to satisfy the conditions outside the crack[ The unknown coe.cients in the series are solved using the conditions inside the crack[ Numerical calculations are performed for several thicknesses of the interfacial layer[ Using these numerical results\ the stress intensity factors are evaluated for in_nitesimal thickness of the layer[ 0887 Elsevier Science Ltd[ All rights reserved