Abstract: The vibration load of equipment mounted on the bogie of railway vehicles is complex and changeable. Compiling an appropriate vibration load spectrum is significant to structural reliability design. At present, the vibration load spectrum (Power spectral density) of equipment is generally compiled with the vibration energy value of the measured load or the measured stationary Gaussian vibration load obtained with the specific operating conditions, but the compiled load spectrum does not have the equivalent damage potential as the non-stationary vibration load of equipment experienced in service. Therefore, a method for compiling the equivalent damage load spectrum for a non-stationary vibration load is proposed based on the fatigue damage spectrum, that is, the time domain method is used to calculate the fatigue damage spectrum of non-stationary vibration load, and the equivalent damage load spectrum is compilated. Then, the compilated method is verified by the measured vibration load and dynamic strain of the wheel flange lubrication equipment mounted on the bogie. Finally, the vibration load spectrum of equipment mounted on the bogie is compilated by the measured vibration load in a maintenance cycle. The research results show that the compiled vibration load spectrum can validly represent distribution characteristics of vibration load energy in the frequency domain and contain more high vibration energy, which has the equivalent damage potential as non-stationary vibration load. Compared with the average spectrum and the standard spectrum, the fatigue damage evaluated by the compilated vibration spectrum is closer to the fatigue damage evaluated by measured stress.

Key words: railway equipment, non-stationary load, fatigue damage spectrum, equivalent damage, vibration load spectrum