Analysis On The Three-Dimensional Crack Propagation Behavior Of Nonhomogeneous Materials

The stress intensity factor is a key parameter to characterize the elastic stress field of the crack tip.It is a key fracture parameter which is most concerned about the crack propagation of the material,especially the brittle material.The classical J-integral method can calculate the stress intensity factor of the crack tip,but can not separate the stress intensity factor of the mixed crack.The interaction energy integral uses the auxiliary field,so that the stress intensity factor of the mixed crack can be separated.In this paper,the typical three-dimensional crack problem of nonuniform material is studied theoretically.The three-dimensional interaction energy of non-uniform material under mechanical loading is deduced.An interactive energy integral expression with no derivative of the material is verified.Under the condition of thermal-mechanical load,the representation of the interaction energy integral.In order to deal with the new thermo-related integral term,a new auxiliary stress field is used to deal with the complex thermal property interface problem.The extended finite element method can effectively deal with the singularity of the cracked stress field by strengthening the function of the crack near the grid.In this paper,the method is used to solve the relevant parameters of the crack tip required to calculate the interaction energy,and the validity and accuracy of the stress intensity factor of the crack tip are verified by the practical examples.