THE ENRICHED FINITE ELEMENT ANALYSIS OF STRESS INTENSITY FACTOR FOR A CRACK NORMALTO BI-MATERIAL INTERFACE

An enriched finite element method is developed to solve the stress intensity factors of the crack normal to bi-material interface. The crack tip asymptotic displacement fields in the method is derived through an approach based on the Williams' series expansion and linear transforms. By incorporating the displacement expressions to the displacement model of common element, the enriched and transition element displacement models are deduced, and the enriched finite element equations are derived consequently. The enriched finite element models of typical plane problem containing a crack normal to bi-material interface are established and the stress intensity factors are obtained directly by solving the enriched finite element equations. Comparisons between the result and published data indicate that the proposed method is fairly accurate and can be conveniently used to analyze the crack normal to bi-material interface.