Variable singularity boundary element and its applications in computation of SIFs

Two boundary elements have been proposed for simulation of variable order singularities in two dimensions. The first can model the variable order strain singularity near a crack tip and the second can simulate both the strain and traction. These elements can be easily incorporated in a standard boundary element computer programme. The elements are useful for computation of stress intensity factors (SIFs) in fracture mechanics. To improve the accuracy of such computations further, a modified crack closure integral (MCCI) based method for mechanical loading are presented. Examples of mode I and mixed mode crack problems are examined to illustrate the performance of the proposed elements and the MCCI based calculations. The effects of order of Gauss quadrature associated with such elements on the accuracy of the SIFs are also reported.