Abstract：
The finite element modeling, the node fracture development of longitudinal variable thickness plate is calculated based on the calculation results based on defect hypothesis and the area of the same principle to determine the longitudinal initial fracture length variable thickness plate; by introducing the equivalent plastic strain index to analyze the longitudinal variable thickness steel plate in key parts of the node the plastic development, according to the longitudinal variable thickness plate in three different shaft should be effective plastic development condition. The cracking index is obtained to analyze the possibility of node fracture of this steel plate.
