Effect of modelling of traction and thermal singularities on accuracy of SIFS computation through modified crack closure integral in BEM

The effect of simultaneous modelling of both strain and traction singularities, and temperature derivative and heat flux singularities at the crack rip, on the accuracy of computation of stress intensity factors (SIFs) based on the modified crack closure integral in boundary element method is presented. Simple relations are given for SIF calculations. Results on mode I, mode II and mixed mode, crack subjected to mechanical and/or thermal loading are studied to illustrate the difference between partial and total modelling of the singularities. The dependence of accuracy of the SIFs on the crack tip element size is examined. The effect of order of Gaussian quadrature on the accuracy is also reported. (C) 1999 .