Study On Gearbox Fatigue Life Analysis By Steinberg Method

High-speed train gearbox is developing to high speed, high torque, and high reliability, vibration is an unable to avoid problem of the high-speed train, which not only directly affects the comfort of train running at a high speed, but also is the important safety impact factors of the high-speed train operation. Vehicle structure fatigue damage problem caused by vibration load was markedly increased accompanying the development of the train, by using a high-speed train gearbox housing test data and combining with the finite element model this paper did fatigue analysis of the gear box, this reseach result can provides guidance to the practical problems of gearbox and technical support for the localization of high speed gearbox.The main work is as follows:Firstly, To obtain the relationship of excitation response amplitude-time, amplitude-frequency and frequency-energy distribution, analyzed the beij ing-shanghai actual track data of the gear box. According to the results of this analysis, the gearbox may occur resonance problem,because vibration frequency of the gearbox mainly concentrated in the 500 Hz～800 Hz, covers the gearbox of the second order intrinsic mode.Secondly, According to the formula of Manson-Coffin and the known material fatigue curve of Al-Si7 -0.3Mg, considering the stress concentration factor, size effect coefficient and surface processing coefficient at the same time, amended the gearbox S-N curve.Finally, fatigue harmonic response analysis showed that the gear box will appear resonance problem under the actual track turbulence, By steinberg cumulative damage three intervals method, fatigue analysis showed that the state of wheel has very important impact on gearbox fatigue life:under the new wheel of state the gear box had vibration more intense and shorter service life; whereas under the state of abrasion wheel the vibration of gearbox is relatively small, so the fatigue life of gearbox can meet the designed life, But comparing different vehicle wheel condition can only be used as a reference.