ANALYSIS OF SURFACE CRACKS USING THE LINE-SPRING BOUNDARY-ELEMENT METHOD AND THE VIRTUAL CRACK EXTENSION TECHNIQUES

The authors have developed a new line-spring boundary element method w hich couples the line-spring model with the boundary element method to deal with the problem of a surface cracked plate. However, the drawba ck of the line-spring model is that a reliable stress intensity factor could not be directly obtained near the free surface Therefore, the v irtual crack extension technique is employed in a post-processor of th e line-spring boundary element method to obtain the stress intensity f actor at the crack front-free surface intersection. Theoretical analys is is described. Stress intensity factors for surface cracks are calcu lated to verify the proposed method. The interaction of two surface cr acks is also investigated. The solutions obtained by the line-spring b oundary element method show that the method proposed is efficient and reasonably accurate.