Numerical analysis for the energy release rate of crack in anisotropic body under combined loadings
Hashimoto-Ken-ichi; Suzuki-Youichi; Yatomi-Chikayoshi
Abstract:For a crack in an anisotropic elastic body subjected to remote inclined load under a plane stress condition, the energy release rate at the onset of crack kinking is analyzed by numerical analysis. The analysis is based on the path independent E integral using the finite element method. The E integral gives the energy release rate at the onset of crack kinking for hyperelastic bodies. The eight-noded and six-noded isoparametric finite elements are used and the integral paths lie along the sides of the finite element. The numerical integration of the E integral formula can be evaluated directly by using the nodal forces and nodal displacements. After the path independency is examined in an isotropic elastic body subjected to the remote constant tension stress, it is shown that the results for inclined loads agree very well with the results by Wu (1978). For the anisotropic bodies, in the cases of different planes of symmetry, the energy release rate is computed first under the perpendicular loading to the crack surface and then under the inclined loading. For the former, the results agree well with the perturbation solutions by Gao and Chiu (1992). For the inclined load, the direction of the maximum energy release rate is more sensitive to the direction of loading than the direction of the plane of symmetry. Key Words:anisotropic elastic body, fracture mechanics, finite element method, crack propagation, E-integral, path-independent integral, energy release rate, crack kinking, combined mode lading