Comparison of different methods of evaluation of weight functions for 2-D mixed-mode fracture analyses

In this paper, two different techniques for mixed-mode type engineering fracture analysis, by using the weight-function method, are presented. These two methods are (a) the virtual crack extension technique (VCE), and (b) the equivalent domain integral method (EDI). For mixed-mode weight-function evaluation, a technique of using two reference load states, both of which cannot be either pure mode I or pure mode II, is combined with the above mentioned numerical schemes. The numerical results show that the weight functions calculated by these two methods coincide with each other well. With the proposed techniques, it is very straightforward to perform fracture analysis of isotropic, orthotropic and composite materials.