残余应力对P91钢断裂行为的影响OACSTPCD

After residual stress was introduced into CT samples by the local out-of-plane compression(LOPC)method,the quasi-static fracture tensile test was carried out to study the influencing mechanism of residual stress on the fracture behavior of CT samples.At the same time,the finite element method was used to establish the evaluation model for the influence of residual stress introduced by LOPC method on the fracture behavior of specimens with different crack depths.The accuracy of the model was verified by quasi-static fracture tensile test of CT specimens.It can be seen from the numerical simulation and test results that residual tensile stress reduces the load and displacement during fracture,whereas the effect of residual compressive stress is opposite;As the initial crack depth increases,there is no significant change in the effect of residual stress on the fracture load,but the effect on the fracture displacement is significantly enhanced;Both types of residual stresses increase the initiation J-integral,but the J-integral corresponding to residual compressive stress is greater than that corresponding to residual tensile stress;As the crack depth increases,the J-integral gradually increases.