Author(s)

W. Wang, M. Wang & Z. Liu

Abstract

As a result of long-time service, cracks started to emerge in traction seats of the 6K locomotive. There is an urgent need for more reliable traction seat structures. The stress-time history of key points of traction seats was measured under 6K locomotive operation condition. By methods of mean stress amendment and load identification, the load spectra for six traction seats were compiled. The statistic inference and the fitting test were processed on the load spectra, and the Weibull distribution function and the maximum load were deduced in order to have a more comprehensive understanding of the load distribution. With the help of ANSYS code, the optimization structures of traction seats were designed and the dynamic stress test was carried out. Combined with the S-N curve and Miner Law, the equivalent stress amplitudes of key points relative to service life were calculated. The results show that all of the equivalent stress amplitudes are less than the fatigue limit and the optimization structures meet with the operation requirement. Keywords: load spectrum, equivalent stress amplitude, Weibull distribution, traction seat. 1 Introduction The traction mechanism, transmitting the locomotive traction force, is one of the most important parts, ensuring the safety of the locomotive. As a result of long service under heavy loads, fatigue cracks emerge in traction seats of the 6K locomotive. The quantity and size of cracks are increasing seriously, which has caused a security risk to the locomotive in service [1].

Keywords

load spectrum, equivalent stress amplitude, Weibull distribution,traction seat