Fatigue life assessment methods for railway vehicle bogie frames

Abstract

The fatigue life of bogie frames directly determines railway vehicles’ reliability and safety. Assessing bogie frame fatigue life is a significant requirement for railway vehicle designs. This paper reviews current railway bogie frame fatigue life assessment methods. These methods use standard-prescribed loads, measured load spectrums or simulated load spectrums to assess fatigue life. The methods of using standard-prescribed loads are categorised into design load methods; they are conservative and are usually used in the design stage or for remaining life assessment. The methods of using measured or simulated load spectrums are categorised into time domain method, frequency domain method, time-frequency domain method, Road Environment Percent Occurrence Spectrum (REPOS) method and bench test method; their assessment has a good agreement with bogie frames’ real fatigue life, but they cannot be used for assessing crack propagation. As for bogie frame fatigue life assessment, standard-prescribed loads and measured load spectrums take into account traction and braking loads. But design loads prescribed by standards cannot reproduce operational scenarios; measured load spectrums reproduce operational scenarios but require longer simulation or measured times, higher cost and are not suitable for the design stage. One research gap has been identified which is that current fatigue life assessment methods based on simulated load spectrums do not consider traction and braking forces.