The dual boundary contour method for two-dimensional crack problems

This paper concerns the dual boundary contour method for solving two-dimens ional crack problems. The formulation of the dual boundary contour method i s presented. The crack surface is modeled by using continuous quadratic bou ndary elements. The traction boundary contour equation is applied for tract ion nodes on one of the crack surfaces and the displacement boundary contou r equation is applied for displacement nodes on the opposite crack surface and noncrack boundaries. The direct calculation of the singular integrals a rising in displacement BIEs is addressed. These singular integrals are accu rately evaluated with potential functions. The singularity subtraction tech nique for determining the stress intensity factor K-I, K-II and the T-term are developed for mixed mode conditions. Some two-dimensional examples are presented and numerical results obtained by this approach are in very good agreement with the results of the previous papers.