Research on Fracture Behavior of 0Cr18Ni9 Stainless Steel Based on the Combination Method of Digital Speckle Correlation Technology and Finite Element Simulaiton

According to GB/T 21143-2014, the fracture test was carried out on the compact tensile specimens of 0Cr18Ni9 stainless steel, the blunting line was observed by scanning electron microscope (SEM), and the strain and stress fields in the crack area were obtained by the combination method of digital speckle test technique and finite element simulation. The results show that the slope of the blunting line of 0Cr18Ni9 stainless steel was about double of that of the recommended experience blunting line of GB/T 21143-2014; the material exhibited high toughness fracture characteristics, and the crack was opened when the specimen was yielding in a large range, and the ligament area had already yielded completely when the specimen cracked; the applicability of the digital speckle correlation technique was verified by the finite element simulation of fracture mechanics, and the digital speckle correlation technology could accurately characterize the structural strain field outside the crack tip ‘singular region’.