Abstract: The differences between the three common fatigue strength analysis methods for bogie frame are studied. Comparison of the three main methods, the normative loading spectrum from the railway standard, the loading spectrum from multiple rigid body system dynamics simulation(MRBSDS) and the stress spectrum from running test, is conducted on one trailer bogie frame under the same precondition. During the analysis, the quasi-static superposition method is used to convert the loading spectrum to stress spectrum. Among the quasi-static superposition method, stress response factor(SRF) is defined, which is useful for the conversion between loading spectrum and stress spectrum. Equivalent stress of one million kilometers is used to contrast the three methods. Though comparative analysis, fatigue analysis results based on the railway standard are conservative and results from the MRBSDS method could not predict the fatigue life accurately. From the frequency domain comparative analysis, MRBSDS method should adopt the real line spectrum which contains high-frequency components and consider rigid-flexible coupled model to create loading spectrum.

Key words: bogie frame;fatigue strength;quasi-static;equivalent stress;comparison