Tension-tension Load of Grade E Steel for Coupler Cast and its Application
The fatigue performance of grade E steel for railway freight car couplers and the life prediction of the coupler were obtained by conducting a high-cycle fatigue test under tension-tension pulsating load,analyzing the fatigue test results,and obtaining a probabilistic fatigue curve P-S-N of the material based on the Weibull distribution function model.Then,the fatigue life of coupler is predicted by combining the converted stress spectrum and P-S-N curve of the material.The results show that the fatigue life of grade E cast steel at the same stress level does not conform to the normal distribution at the stress levels of 450 MPa and 400 MPa corresponding to about 105 cycle life and 3×105 cycle life,respectively;the fatigue life of grade E cast steel conforms better to the Weibull distribution in the range of 105 to 107 cycles.Using the maximum correlation coefficient optimization method,the parameters of the Weibull distribution at different stress levels were determined,and the P-S-N curve with a failure rate of 1%and the median S-N curve with a failure rate of 50%were obtained for the grade E caste steel under tension-tension load.The stress spectrum of the dangerous part of the coupler was obtained by converting the load spectrum of the coupler bench test,and the fatigue life of the coupler in case of cracking was predicted by combining with the P-S-N curves of the material,and the prediction results were in line with the test results.
railway freight carcouplergrade E cast steelfatigue lifeP-S-N curve
NETL
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万方数据
