Finite Element Simulation and Experimental Verification of Fracture Properties of 316L Stainless Steel Formed by Selective Laser Melting

Representative volume element (RVE) model of 316L stainless steel formed by laser selective melting (SLM) considering the microstructure characteristics was established by crystal plasticity finite element method and cohesion model. Based on the stress and strain datas, the fracture process of the compact tensile specimens formed by SLM with different volume energy densities was simulated, and the J-integral curve was obtained and compared with the experimental results. The results show that the internal stresses of 316L stainless steel specimen formed by SLM were not uniform during tensile deformation. The true stress-true strain curve of specimen under different volume energy densities was different after the maximum nominal stress of cohesion element was changed, which was more consistent with the experimental results. The simulated J-integral values of specimen formed by SLM with different volume energy densities were basically consistent with the experimental values, and the root mean square error was 4.66-12.88 kJ·m^-2. The RVE model and the simulation method used could effectively simulate the fracture toughness of 316L stainless steel formed by SLM.