Numerical Study On Stress Intensity Factor Of Bimaterial Surface Crack

With the fast development of modern industrial technology,composite material is extensively used in many areas.Studying the fracture strength of interface in composite material system has important theoretical significance,and can provide foundation for the design and preparation of composite material.In this dissertation,finite element method is applied to analyze interface stress and stress intensity factor of crack in bimaterial surface crack system numerically.In this study, interaction integral method is applied to achieve the solution of stress intensity factor under tensile stress and thermal stress,and displacement extrapolation method is used to calculate the dynamic stress intensity factor under thermal shock in coupled field . The main work and achievements are as follow:For the tensile stress of bimaterial surface crack stress intensity factor, variation of stress intensity factor under different ratio of the ellipse axial, different model thickness and different elastic modulus ratio have being analyzed.For the thermal stress of bimaterial surface crack stress intensity factor, variation of stress intensity factor under different ratio of the ellipse axial, different model thickness and different elastic modulus ratio have being analyzed.Displacement extrapolation method is applied to study the two-dimensional crack stress intensity factor of single isotropic material, and the result agrees with the existing one well, then the methods is used to study the bimaterial two-dimensional crack and bimaterial surface crack under thermal shock.