Research on Residual Life Prediction of CRH2046 Train Bolster

The bolster is one of the key components of a train. It is subjected to the complicated alternating load such as tensile, compression, torsion in various directions in practical application, and the fatigue crack initiation and propagation is the major failure mode of the bolster. In this paper, it is taken that the bolster of CRH2046 train after a period of service as the research object. Based on the fracture mechanics, the residual life prediction method of the bolster with the pre-existing cracks is researched. First, three-dimensional solid modeling and finite element strength analysis are carried out on the integral structure of the bolster with surrounding components to determine the stress distribution characteristics of the critical region of the bolster. Second, the sub-model technique is applied to establish the equivalent finite element model of the critical region. The function of stress intensity factor changing with crack morphology and relative crack depth is obtained. At last, the process of predicting the residual life the bolster under the two stage of the crack propagation is presented.