Fatigue Reliability Analysis Of K6Bogie Bolster Springs

Abstract:In recent years, China’s railway has make improvements in speed and heavy load,which also make higher demands for the vehicle components. Bolster springs of trucks’bogie are the key components,which play a major role in load transmission and vibration or shock buffering caused by track line. Therefor, Bolster spring fatigue and reliability are issues that need focus.The study of spring fatigue and reliability and sensitivity is very important for the operation and safety of trucks,in order to ensure reliable operation of the spring,we must make the mutual combination of theoretical research and theories.This article will treat K6Bogie Bolster spring of C80B as the research object, based on laboratory measured60Si2CrVAT P-S-N curve,using the measured load spectrum to assess the fatigue life, while establishing the reliability of the model of the spring, the key elements is shown as follows:(1) Through line experimentally measured center plate and side bearing load spectrum, then through stress analysis to transfer it into springs’stress spectrum, and determine it’s distribution type.(2) Make a P-S-N curve according to the experimental methods, while taking into account the various factors that affect the fatigue strength, finally acquire the springs’ P-S-N curve.(3) According to the Miner linear damage accumulation theory,consider the spring stress spectrum and P-S-N curve to calculate fatigue life of the spring, finally, compare the results with alternative results according to the AAR load spectrum to examine the accuracy.(4) Establish the reliability of the springs’model, use Monte Carlo simulation theory to programme,and acquire relevant reliability indicators.(5) According to the results of Monte Carlo simulations, based on the theory of reliability and sensitivity, calculate the sensitivity of four random variables to varies of reliability and sensitivity, and make the sensitivity curve, analyze the final result.