The Numerical Simulation Based On The Residual Stress And Defect Fracture In Small Punch Specimen

Small punch test is a new kind of evaluation material performance parameters Micro-sample testing methods, the test methods obtain material mechanics performance while maintaining the non-destructive sampling, so it can be used on equipment in service, that is, it can test material performance parameters without impacting on equipment. Therefore, a launch would have been wide concern.The paper obtained material elastic-plastic parameters by repeatedly adjusting GTN damage parameters combined experiment, then carried on simulating for the tensile test until until the test and simulation of displacementload consistent, in order to determinethe material damage parameters, and compared two breaking section contraction rate. Small punch test process is simulated by obtained damage parameters and elastic-plastic performance, it finds that there are a few differeces between the simulated displacementload curve and experiment datas, but it’s a reasonable range. By differen size of tensile test and the first stress fracture unit stresss-train curve of the small punch test, it finds that the curve trend acquaintance, maximum stress is corresponding to the same strain.Otherwise, the paper introduced residual stress simulation,the results show that the greater the residual stress, the greater the impact on the material properties, the residual strain is the key factor affecting the material properties,rather than stress. V-ring cracked specimens containing defects simulation results show that the defect is farther from the central axis, it has from the central axis,it has a greater impact on the J-integral in crack region, the greater the region, the greater the defect rate along the thickness direction from the upper surface, smaller the J-integral value.