A Study On Dynamics Performance Of The Vehicle With Coupled Wheelset

Since railway is plunged into business, the wheelsets with two wheels fixed to two ends of one axle are commonly adopted in rail vehicle. The advantage of conventional fixed wheelsets is that they have self-steering capability produced by lognitudinal creep moments, however hunting unstability possibly occur when the speed of vehicle becomes higher, so independently rotating wheels are attached importance to increasingly. Independently rotating wheels don't engender lognitudinal creep forces, so hunting won't occur and the stability of vehicle system is very good. But independently rotating wheels lose self-steering capability of lognitudinal creep moments, so its restoration capability and curving performance becomes worse. Thereupon, the idea of coupled wheelsets is brought forward that the left and right wheels of wheelsets are coupled properly to produce a few lognitudinal creep forces. In this way, coupled wheelsets have both self-steering capability and higher critical speed. Some researches about coupled wheelsets have been carried through abroad, however research about coupled wheelsets is basically a blank in homeland. In order to fill up the research blank and speedup the progress of heightening train's speed, in-depth research about coupled wheelsets is very necessary. In this paper, based on the study about coupled wheelsets abroad, author have brought forward a kind of new coupled wheelsets-magneto-rheological coupled wheelsets(MRCW).In this paper, the structure scheme of magneto-rheological coupled wheelsets is designed and its work principle is analyzed. Afterwards, a 38 d.o.f. nonlinear dynamics model of vehicle system with magneto-rheological coupled wheelsets is established and the relevant computer simulation program is written.According to the computation result of dynamics simulation software, the response and stability on the tangent track and curve performance of the vehicle with magneto-rheological coupled wheelsets are analyzed comprehensively and the laws of coupled coefficient to dynamic performance of vehicle are found.In this paper, optimization of coupled coefficient for the leading wheelsets and trailing wheelsets of bogie is researched with genetic algorithms and the optimal matching law of coupled coefficient for leading and trailing wheelsets has been found when a vehicle negotiates all kinds of radii curve.In this paper, the dynamics problem of train with magneto-rheological coupled wheelsets are also researched and put forward a new method of computing train dynamics-cycle variable method. In succession, a train dynamics model based on cycle variable method is established and the relevant computer simulation software on train dynamics is drawn up. By comparing dynamics performance of the train with traditional fixed wheelsets, independently rotating wheels and magneto-rheological coupled wheelsets, it is approved that magneto-rheological coupled wheelsets are superior to the others.The merit of magneto-rheological coupled wheelsets is that the coupled coefficient of MRCW neatly could be changed under the control systems so that vehicle dynamics performance could keep best ever and again. However, the exertion of its superiority needs the support of relevant test, control techniques. It just right provided impelling theoretical basis for the development of control system that the research on dynamics performance of magneto-rheological coupled wheelsets in this paper.