Computational Technology Resources - CCP

Keywords: electric multiple unit underfloor equipment, bearing structure, load spectrum, rainflow extrapolation, kernel method.

Summary

The total weight of a high speed electric multiple unit (EMU) carbody is about 35 tons, which includes 6 to 10 tons of underfloor equipment weight. The single weight of some underfloor equipment is even 6 tons, so the bearing structure for the equipment works in a severe environment. To ensure the reliability of the bearing structure, a fatigue test is necessary. In this paper, the compilation method of the fatigue test program load spectrum was studied. At first, the extrapolation method of multiple load histories was presented, which was based on a multiple load history rainflow matrix and two-dimensional kernel density estimation theory (KDE). According to the rainflow counting matrix, the compilation of the fatigue test load spectrum was completed by applying a mean stress correction equation, the cumulative damage theory and the equivalent damage criterion. The extrapolation method was verified using the EMU underfloor equipment line test vibration data, then the fatigue test load spectrum of the equipment bearing structure was compiled. The extrapolation results of line test data show that error of damage between the KDE extrapolated load and the actual load is 3.6 percent according to the three test samples. The low cycles and large amplitude load could be obtained by using the KDE extrapolation method when the extrapolation scale is large enough. The damage calculation results show that damage from the block load spectrum increased by 43.8 percent compared with that from original vibration data. So, in the compilation of the fatigue test program load spectrum, it is essential to calculate the high-amplitude load which may occur. This research provides a load spectrum compilation reference for other bearing structures.

purchase the full-text of this paper (price £22)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £85 +P&P)

	Computational & Technology Resources an online resource for computational, engineering & technology publications
	not logged in - login
Front Page Browse CCP CSETS CTR IJRT Other Authors Search Purchase Guide FAQ Contact us	Civil-Comp Proceedings ISSN 1759-3433 CCP: 110 PROCEEDINGS OF THE THIRD INTERNATIONAL CONFERENCE ON RAILWAY TECHNOLOGY: RESEARCH, DEVELOPMENT AND MAINTENANCE Edited by: J. Pombo Paper 213 Generation of a Load Spectrum for an Electric Multiple Unit Underfloor Equipment Bearing Structure based on a Kernel Estimation Method F. Li and P. Wu Southwest Jiaotong University, China doi:10.4203/ccp.110.213 purchase the full-text of this paper Full Bibliographic Reference for this paper F. Li, P. Wu, "Generation of a Load Spectrum for an Electric Multiple Unit Underfloor Equipment Bearing Structure based on a Kernel Estimation Method", in J. Pombo, (Editor), "Proceedings of the Third International Conference on Railway Technology: Research, Development and Maintenance", Civil-Comp Press, Stirlingshire, UK, Paper 213, 2016. doi:10.4203/ccp.110.213 Keywords: electric multiple unit underfloor equipment, bearing structure, load spectrum, rainflow extrapolation, kernel method. Summary The total weight of a high speed electric multiple unit (EMU) carbody is about 35 tons, which includes 6 to 10 tons of underfloor equipment weight. The single weight of some underfloor equipment is even 6 tons, so the bearing structure for the equipment works in a severe environment. To ensure the reliability of the bearing structure, a fatigue test is necessary. In this paper, the compilation method of the fatigue test program load spectrum was studied. At first, the extrapolation method of multiple load histories was presented, which was based on a multiple load history rainflow matrix and two-dimensional kernel density estimation theory (KDE). According to the rainflow counting matrix, the compilation of the fatigue test load spectrum was completed by applying a mean stress correction equation, the cumulative damage theory and the equivalent damage criterion. The extrapolation method was verified using the EMU underfloor equipment line test vibration data, then the fatigue test load spectrum of the equipment bearing structure was compiled. The extrapolation results of line test data show that error of damage between the KDE extrapolated load and the actual load is 3.6 percent according to the three test samples. The low cycles and large amplitude load could be obtained by using the KDE extrapolation method when the extrapolation scale is large enough. The damage calculation results show that damage from the block load spectrum increased by 43.8 percent compared with that from original vibration data. So, in the compilation of the fatigue test program load spectrum, it is essential to calculate the high-amplitude load which may occur. This research provides a load spectrum compilation reference for other bearing structures. purchase the full-text of this paper (price £22) go to the previous paper go to the next paper return to the table of contents return to the book description purchase this book (price £85 +P&P)
Back to top	©Civil-Comp Limited 2023 - terms & conditions