Application Of BEM To The Interface Crack Problems

In this paper, Subfield BEM is used to study the two-dimensional bimaterial interface crack issues. The material is divided into two subfields along the crack facet and interface, where integral equation is solved by discrete unit on the boundary. Then two independent equation groups will be formed. Consider the relations of the two materials' displacements and surface stresses in the interface, the equation groups could be solved. Then all the displacements and surface stress on the boundary become be given and that in the arbitrary site of inner field can be derived by changing the integral points.Base on the given interface displacements and surface stresses, the SIF will be obtained by extrapolation techniques. Accordingly, Stress Triaxiality, Strain Energy Density Factor and Maximum Circle Tensile Stress near the crack tip and their variation due to the circle angle variation can be derived. And then the variant trend of each parameters due to the variation of external loading conditions from modal I to mixed modal by I and II, the difference of material and ratio of crack width supplying the reliance for studying further the extension of crack.Comprehensive analytical results indicates that Stress Triaxiality and Strain Energy Density Factor can be act as fracture parameters to analyze the extension of crack and Maximum Circle Tensile Stress can not do because of errors normally .Subfield BEM fits to treat the bimaterial interface crack problems, which is practical to investigate the extension of crack.