A virtual crack closure technique based on EFG method for thread-shape crack was introduced. The cracked component was discretized and the displacement field was determined using a coupled FE/EFG method, by which EFG nodes were arranged in the vicinity of crack tip and FE elements in the remain part in order to improve computational efficiency. Two typical parameters, nodal force and crack opening displacement attached to crack tip were calculated by means of setting up an auxiliary FE zone around crack tip. Strain energy release rate(SERR), further stress intensity factor(SIF) were determined by the two parameters. The method to calculate SIF was named as virtual crack closure technique based on EFG method. Several numerical examples using the presented method showed that SIF on the crack tip can be obtained accurately.
