| For the vehicle R.&D.demands of speeding-up freight rails and rapid and/or high-speed passenger rails,the main contradictions should be held closely between the two important non-linearities of wheel-rail contact and bogie suspension,and to construct the late-mode software analysis and synthesis platform for both Dynamical Design Methodologies(DDM)of bogies and rigid-flex coupling simulations of full vehicles,by which some breakthroughs and innovations can be achieved,i.e.the design theoretical methodologies and the software analysis knowhows.To overcome the boundedness and one-sidedness of quasi-state design methodologies,the research themes in the paper were described definitely,i.e.the speeding-up bogie DDM and corresponding technical supports of software platform,and the two main research problems were then proposed explicitly,that is,the limited speed and construction speed can be promoted rationally and scientifically.In Chapter one,the concrete cases of rapid freight bogie and technical difficulties of wear and abrasion reduction were discussed firstly for speeding up freight rails;combined with the running and maintenance practices of rapid and/or high-speed passenger rails and relevant technical problems,the two non-linearities effects of wheel-rail contact and bogie suspension were furthermore expounded profoundly,both of which are correlated with each other,and the strong non-linear system can therefore be formed consequently;finally,from the Winckens' stability analysis viewpoint for worn wheel-rail relation,the(non-)linear theory of Kalker's wheel-rail contact and its technical intensions were explained adequately.I.e.only if the actual wheel-rail contact is approaching to the near linear relation in track windows,the wheel-rail surface wear work consists only of longitudinal and lateral components,and the wheel normal tread wear is then formed.Otherwise if deviated from to the near linear relation,e.g.the local close-conformed contacts and small hunting oscillations,and the negative fluctuant effects to wheel-rail wear and abrasion are then needed to be considered due to the wheel spin singularities and corresponding spin couples.According to the Lagrangian mechanics and three basic equations,the following two scientific problems were summarized briefly in Chapter two with consideration of relevant engineering demands,i.e.i)in the track window,the(non-)linearity dialectical relations of wheel-rail contact should be held closely,and the two instabilities of carbody and bogies can be then transacted correctly,in order to maintain hard the wheel tread normal wear;ii)in broadening velocity window,the correct recognition of bogie suspension non-linearities should be understood gradually so as to avoid as possible the correlation excitations to be formed between light-weight carbody and running gear.The late-mode software analysis and synthesis platform was therefore built specially,by which the two innovations and breakthroughs can be gained as follows:i)the system design of bogie parameter configuration can be guided by the root-locus graphs,e.g.analysis method of full vehicle stability property and evolution pattern,to instruct correctly the safety design of high-speed bogies;ii)by applying the rigid-flex coupling simulation techniques of full-assembled vehicles,the local high-stresses and their influential extents to structural fatigue damage can be determined accurately with the complex constraints and their inner force precision analyses.Combined with some typical cases studies,the stability property and evolution pattern of half-/full-vehicles indicate that the wheelset self-instability and the rotational resistance moment effectiveness are the two important technical problems to wear and abrasion of high-speed wheel-rail contact.Especially for the prototype design of ICE3 serial bogies,the primary hunting phenomenon exist and its negative effects to the wear and abrasion of wheel-rail contact can not be neglected at all.Notwithstanding,the ETR serial bogies and their improved designs can be taken as one of typical cases of comprehensive performance designs.Considering the mechanical features and non-linear evolutions of bogies suspensions,the general interfaces of flex-body to MBS were proposed further,including the transactions of five-level important technical relations,by which the concrete case study was presented for the lateral coupling vibration explanation of full-assembled aluminium carbody.For the adequate demonstrations and validations on the feasibility and correctness of the late-mode software analysis and synthesis platform,the following application research achievements of five engineering cases were presented in Chapter 3-7,the simulation models of which have be examined sufficiently through the measuring data from approval tests,tracking line tests and dynamical testrigs:(1)ICE3 improved design based on anti-yaw parallel connections.Mixed together with the technical features of Japanese Shinkansen and European rails,the novel theory of anti-yaw wide-band absorption was therefore proposed to instruct correctly the safety design of high-speed bogies.I.e.for the anti-yaw parallel connections with the deferent working principles of mono-and dual-circulations,the dynamical testrig shows that the dynamical features have the similarity to the lead-lag correction.By applying this similarity,the solution of ICE3 improved design was formulated,including the parameter optimal configuration of anti-yaw dampers and the optimization design of partial bogie parameters.The assessment analyses of safety and comprehensive performances based on non-linear simulations indicate that i)the primary hunting phenomenon disappears completely by applying the ICE3 improved design solution,?eN=0.10,Vlim?480 km/h;ii)and the prototype design defaults in ICE3 serial bogies are overcome throughly,and the three important negative effects are avoided or relieved as possible,i.e.the conditionality to wheel-rail matching,the sensitivity to wear and abrasion of wheel-rail contact and the lateral vibration coupling mechanism;iii)the ICE3 improved design can modify and enhance the adaptability,friendliness and stability robustness to railway lines and service technical conditions.(2)Studies on vibration reduction solutions of high-speed pantograph based on dual-coupling of Wheel-Rail and Pantograph-Catenary.The wears and/or abrasions of both wheel-rail and pantograph-catenary are originally not correlated with each other.But if the harmful tread wear occurs on some wheels,the dynamical interactions of wheel-rail contact will become one of main associated factors to form the dual-coupling of wheel-rail and pantograph-catenary,and which cause the problems of high-cycle fatigue on high-speed pantograph.Considering the influential factors to high-cycle fatigue,the relevant analyses of some typical cases can prove sufficiently the dual-coupling simulation model correctness of wheel-rail and pantograph-catenary,and the basic principle of high-speed pantograph light-weight design was proposed as follows,i.e.the frequency of lower-order mode>12 Hz.Combined with the R.&D.demands of 400 KMH High-Speed Rolling Stock,the structure design of next-generation high-speed pantograph was presented through the contrast analyses of five original and improved designs,which is an innovative achievement of integrated system techniques,i.e.the high-cycle fatigue is transformed into the static strength problem.(3)Contrast investigations of rigid-flex coupling vibration simulation and testrig of.160 KMH rapid covered cars.For the technical prototype of a rapid freight bogie,in which arm-axlebox is used instead,the R.&D.solution of 160 KMH rapid covered cars was approved through the expert demonstration,which satisfies the technical condition of minimum axle load>(7-8)t in tare.According to the two-stage suspension particularity of the rapid freight bogie,i.e.K2>>Ki,the simple airsprings are necessary to replace the tare rubbers in secondary suspension,so as to avoid the vertical correlative excitations between bogies and ca.24 m long floor frame.Correspondingly,the roof original design should also be improved,which consists of stable triangle beams in series,and its fundamental frequency can be increased through the inner tension force by applying the support posts of both end walls.Similar to the Y37,the side-bearing friction instability also exists on the elastic-supported bolsters.If the following matching wheel-rail condition is still required,like?eN=0.10,?eMAX=0.35,the anti-yaw dampers are then necessary to be added.Otherwise,according to the small-creepage solution to wear and abrasion of high-speed rails,the practices of rapid freight rails can actively share of some technical achievements coming from the applications of passenger rapid rails,i.e.?eN=(0.03-0.06),maximum value recommended 0.15 or little more than 0.15,without anti-yaw damper configuration.(4)Analyses for system inner force and reliability of two-vehicle trainset for piggyback transportation.With dynamical simulation instead of manual calculation,the system inner force analyses for rolling on/off operations show that the slipway,consisted of movable and stationary parts with the three suppotting points of rails and platform,is a typical mechanical problem of static indetermination.Considering the hight error of platform,ca.±5 mm,if the wrong manual operations occur,the slipway will be tilt,and the shock forces of lateral swing bumpstop cause the structural instability of both-side upright columns with lift cylinders to be transformed into vibration fatigue problem,e.g.the local higher stress presented on the arc partial of outer-side stiffened plate on top upright columns,the maximum value of which is reached to ca.320 MPa.The collaborative innovations from the hydraulic professional efforts are therefore needed so as to avoid as possible the manual operation error by applying the one-touch operation.(5)Non-linear influences of freight bogies and technical strategy.By applying the rigid-flex coupling simulation techniques,the analyses for two typical engineering cases of container flat car and piggyback wagons indicate that the laden clamping stagnation is one of main contributing factors to form the correlative excitations between the light-weight carbody and running gear.Under the negative effects of laden clamping stagnation,the typical mechanical problems can be transformed into the failures of vibration crack or structural fatigue,e.g.the inclined rod structural instability of middle lateral trestle and the lateral structural instability of middle side-walls.For the rational exploration of the technical potentials for light-weight carbody designs,the technical solution to laden clamping stagnation should be formulated necessarily.I.e.by applying the novel techniques of compound wedge,the typical structural configuration is selected properly and the top angle is increased suitably so as to remove or decrease the strong non-linear effects of bolster suspension with fry friction damping. |
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