Elastic-Plasticity Analysis Of Ⅰ/Ⅱ Mixed Mode Crack And Probability Caculation Of Fracture Failure

Engineering structure or components during service will inevitably have the crack,while the component due to the cack orientation, geometry,orientation and materials contained by the anisotropy of the impact of such factors is often manifested in the case of mixed crack mode.Based on the HRR singular solutions theory about crack tip elastic-plasticity developed by Hutshison,Rice and Rosengers,we analyze the small scale yielding problem ofâ… -â…¡mixed mode crack mode under the plane stress and plane strain.Meanwhile,we give the detailed expression of the mixed mode's controlled equation.The numerical calculation methods about the mixed crack mode are also given.In the defective component of the safety evaluation,assessment of the life and failure probability calculation,many of the tests and analysis show that the specimen geometry,the way of load will have different constraint effects.In this article,we use the T-stress to describe the constraint effects. On the basis of the fracture criterion associated with the crack tip constraints,the Mont-carlo is used to calculate the failure probability of oval-shaped cracks on the surface of the thick-walled steel cylinder. Compared with the results of the failure assessed based on the traditional R6 curve,the results showed that the crack effects of different constraints have major impacts on the failure probability.