Abstract:  Aiming at the optimization to determine the number of meshes on the end face and axial meshes of a threedimensional cracked body, the grid parameters of the crack front of the belt pulley with opening surface crack were studied by orthogonal experiments based on the stress intensity factor theory. Firstly, the orthogonal design theory and the displacement method calculation principle of the stress intensity factor were studied. Secondly, a crack of a certain size was established at the stress concentration position of the spinning pulley and the stress intensity factor of the crack was calculated. Finally, the orthogonal design method was used to design the experimental schemes of different factor levels of the grid around the cracked body. According to the results of the I-type maximum stress intensity factor, the number of grids around the cracked body was studied. The results show that the radial mesh number has the greatest impact on the maximum stress strength factor of belt wheel crack type I, followed by the number of circumferential mesh, and the axial mesh number has the least impat. After orthogonal optimization, as the best grid division scheme for the crack structure: the radial grid number is 8,the number of circumferential grid is 16, and the number of axial grids is 15.

Key words:  belt wheel;threedimensional cracked body; stress strength factor;orthogonal experimental design;mesh number