Calculation of the Stress Intensity Factors of Three Dimensional Interface Crack Under Mechanical and Thermal Loading Using Universal Weight Function Method
Abstract:Crack propogation in bimaterials and composites tends to occur at the interface when they withstand mechanical and thermal loadings, most cracks in engineering practice are three dimensional cracks, the traditional numerical methods such as finite element method and boundary element method for determination of transient stress intensity factor of interface crack under mechanical and thermal loadings are inefficient due to large amount of calculation. The universal weight function (UWF) is only dependent on the crack configuration and body geometry, and is independent of temperature fields and time, which avoids the repeated determinations of stress field for individual time instants and has an enhanced efficiency. The UWF method is especially suitable for determining the variation of transient stress intensity factors of an interface cracked body subjected to thermal and mechanical shock. The basic equation and finite element implementation of the UWF method for three dimensional Mode I, Mode II and Mode III interface cracks subjected to thermal and mechanical loadings is given in this paper based on Betti’s reciprocal theorem. Numerical results show that the UWF method is of good accuracy and satisfies the engineering application demand.