Study On Fatigue Reliability Of Bolster Springs Of Railway Truck Bogie

The railway transportation in China is developing quickly with the aim of high-speed and heavy load. It will cause much more requirements for the fatigue strength of the truck's components. As one of the most important components of truck bogie, bolster springs are fatal in evenly transmitting truck's load, alleviating vibrate and collision which produced by track irregularities. It is necessary to study the fatigue reliability of bolster spring for ensuring running security.The bolster springs'fatigue reliability is significant for the running security, design, production, maintenance and standardizing. At the same time, present bolster spring has adopted new material 60Si2CrVAT, so it is imperative to evaluate its reliability totally and scientifically.This paper takes the bolster spring of K6 bogie of the C70-General gondola car as the study object. On the basis of the test data of 60Si2CrVAT and the AAR load spectrum, there is a evaluation about springs' fatigue life. Then the thesis put forward a reliability model to estimate springs' fatigue and totally analysis their reliability. As a result, the following research has been done:1. Based on the data of fatigue strength test and material attribute, got the S-N curve of springs, and estimated springs'life by the test load of Ministry of. Railways.2. Springs had a detailed analysis based on the bogie's structure. After the AAR load spectrum, including the load spectrum of center plate and side bearings, was transformed into springs'load spectrums, the fatigue life of springs have been predicted respectively.3. On the basis of theory of Miner linear damage accumulation, allowed for fatigue strength, material attribute, and geometric parameter, a fatigue reliability model of spring was built and implemented by Monte Carlo method,. Finally, it got the related reliability parameters.4. Springs'fatigue lives have been fitting by the result of Monte Carlo method simulation. When comparing with several normal reliability models, there is a analysis about system reliability of bolster springs.5. Study springs'fatigue lives when the system has fault and some advices about maintenance were given.