Fatigue Life Estimate And Fracture Safety Evaluation Of Bolster For The 30t Axle Load Bogie

As China's rail transport to the development of high-speed and heavy load, bogie bolster runs in increasingly harsh conditions and the failure rate of bolster crack is getting greater. The failure of the bolster fatigue crack appears increasingly prominent, and has become an important factor in vehicle development. So it has great significance to research the problem of bolster fatigue fracture under the conditions of high-speed and heavy load. The object researched in this paper is 30t axle load bogie B~+ grade steel bolster and it has been analyzed under steady load using ANSYS. The fatigue life of the bolster is been estimated under AAR load spectrum. Based on fracture mechanics method, crack security measure of the bolster, crack propagation law and the residual life of the bolster have been studied in the thesis. It has provided a theoretical basis for making a reasonable and scientific inspection periodicity and managerial method.The primary work and remarks of the thesis are as follows:1. The S-N curve of B~+ grade steel bolster has been fitting by choosing the three-parameter model according to AAR standard.2. By using Pro/E the three-dimensional model of bogie bolster is been established. By using large-scale finite element analysis software ANSYS, the finite element stress analysis of Bogie Bolster was done and the fatigue weak positions of bolster have been identified according to the calculation results.3. The fatigue strength of the bolster is evaluated under the fatigue test load according to AAR standard M-202-05 and the pulse cycle S-N curve of B~+ grade steel.4. The fatigue life of the bolster is estimated under AAR bolster load spectrum according to the nominal stress method and the Miner principle of linear cumulative damage.5. Based on simplifying surface defects and buried defects in steel, crack security measure of the bolster is analyzed according to the stress intensity factor formula of existing rules model, while fatigue crack propagation and residual life prediction model of the bolster are established by using the Paris formula and its residual life is estimated.