A numerical model for simulation of crack initiation around inclusion under tensile load
Non-metallic inclusions are still the key problems in material manufacturing, which affect significantly the plasticity of material. There are three kinds of conditions between inclusion and matrix: (a) bonding; (b) separated; (c) with transition zone. For case (a), the nodes in the interface of inclusion and matrix will be the same; for case (b), the nodes in the interface of inclusion and matrix will be different. However, for case (c), it will be difficult to establish as the bonding force between inclusion and matrix is unknown and variable. In this paper, a finite element model, with a transition zone between matrix and inclusion was used to set up the bonding force between inclusions and matrix, was presented for dealing with all three cases. The finite element model was used to simulate micro-crack initiation around a 2 × 5.5 μm inclusion in samples under tensile load. The initiation of crack around the inclusion at different loading was obtained under different bonding strength between inclusion and matrix. The calculated results were in good agreement with the experiments. Finally, we discussed the different initiation methods of cracks around inclusions in a sample under tensile load.