Study On Dynamic Design Of EMU Based On Experimental Modal Analysis

Now railway industry develops quickly in China, the sixth passenger train speed lifting has been carried out. To vigorously develop the high-speed railway, higher requirements has been put foward for high-speed multiple units vehicle Systems. Because of track irregularity, the motions of the wheelset, as well as the vehicle suspension systems' own characteristics, the complex vibration of the vehicle is caused, which has obvious influence on the comfort and damage of the goods. Comprehensive research on the modal analysis of the vehicle systems is the key to jude the dynamic quality of the high-speed EMU.Vehicle system's dynamic charactices are been deeply analysised by combining methods of calculated modal analysis and experimental analysis.The principle of modal analysis and several modal parameters identification methods are briefly introduced.Based on the MATLAB development environment, the lateral and vertical dynamic equation of railway passenger vehicle are generated respectively, the theoretical modal parameters are calculated after transferred into the state space equations.The modal experiment's scheme is designed, the EMU vehicle is exciated by sweep sine singnal and the track spectrum on the rail-vehicle roller test-rig, and the modal paramters of the EMU on embient exciation is indentified by PolyMax method. The results show that the dynamic design of the EMU's vehicle meets the related requirtment.The effect of the modal parameters on vertical ride comfort index is anlysised and discussed, that is a good reference for solving practical problems. The results show that the vertical load should be away from 1Hz～2Hz,and the first modal damping ratio should be between 0.08and 0.18.