Study on the stress intensity factor for mixed mode surface crack under three point bending

In the virtual crack closure method (VCCM), the energy release rate is computed based on the results of finite element calculation, and the stress intensity factor (SIF) is computed from the energy release rate. In this paper, the stress intensity factor of mixed-mode surface cracks under three point bending is studied by using the three dimensional modified virtual crack closure method (MVCCM). The modified virtual crack closure method is required to open one element face area whose shape is arbitrary and finite element widths are unequal across the crack front. The effect of the distance between the location of load and crack face, crack shape and crack depth to the stress intensity factor is also discussed, along with practical results and conclusions.