Analysis and simulation of stochastic fatigue reliability for running system of complicated equipments

Actual equipment experiments are adopted to measure the load spectrum of torsion shaft. Virtual prototyping supplement the load spectrum that cannot be measured by actual experiments. The comparison and analysis between actual vehicle experiment data and virtual test results of virtual prototype verify their complementarities, which provide full and accurate load spectrums for the key components. Combined with material´s S-N curve, stress and strain spectrums can be obtained. To analyze the stochastic fatigue reliability accurately, nominal stress method and local stress and strain method are combined with probability density accumulation damage theory to compute the probability density distribution function. The computational results of stochastic fatigue reliability provide sufficient reference for determination of appropriate maintenance cycle and prediction of running system reliability.