Fatigue life assessment of the bolster of railway bogie under non-Gaussian load

Bogie is a multifunctional part of a rail car that is subjected to the random forces. The ran-dom forces, which has been made by the irregularity of the rail, cause the fatigue crack, and these cracks are as a threat to safety of the Railway systems. As the statistics show, the fa-tigue cracks make around 40% of defects of bolster of the bogie. In this article, by using a combination of multibody dynamic analysis and FEM analysis in frequency domain, the fa-tigue life time of the bolster has been investigated. After verifying the multibody dynamic model, the forces in three direction have been obtained. The forces are as an input to FEM analysis; thus, von misses stress has been calculated as an equivalent stress. The multiaxial random fatigue life of the bolster has been assessed by using the Rayleigh method and Wang Factor for non-Gaussian signals; and a thorough parametric study is achieved and effects of different parameters, such as the load on the train and train speed, on fatigue life time are investigated. Finally, the results show a noticeable deviation between Gaussian and non-Gaussian method.

Keywords:

Random Load , Multiaxial Fatigue , Power Spectral Density , Bogie.