Study Of Low Floor Light Railway Vehicle Dynamics

Low floor light rail vehicle plays important role in urban mass transit system,filling up the vacancy of one-direction6000-10000people per hour transport capacity.It says ‘encourage development of mass transit system such as light rails\trams etcthat run on elevated or tracks’in the document issued by National Development andInnovation Committee about strengthening urban mass transit layout and constructionmanagement. There is a huge structure difference between current light rail vehiclesin service and traditional four-axles passenger cars, such as, light rail carbody moduleis conneceted by articulations instead of couplers; bogies with two different runninggears that is independent wheel and regular wheel-set are installed on a same trainset.These special structure causes special vibration during light rail vehicles running.Some vibration severely affects ride comfort. With light rail vehicles demandincreased in many big cities, it’s necessary and meaningful to deeply study theabnormal dynamics of this type of vehicle and the solution to it.This article takes100%low floor LRV and70%low floor LRV as examples todescribe vehicle system from different dynamics point of views and for the first timeto completely set up two different types of vehicles lateral and vertical dynamicsmath models. With Simpack software, set up system dynamics MSB modelconsidering nonlinear factors during vehicle vibration. At the same time, withdynamics test analyze the factors affecting vehicle vertical and lateral vibration. Withoptimizing suspension and articulation parameters, improve vehicle vibrationperformance. Also, regarding to vertical and lateral vibration problems forarticulated LRV vehicles, this article generates the analysis procedure based on testresults. The procudure lists parameters of different systems affecting vehicleperformance. it is helpful and guidance for design suspension system in future andalso for resovling existing vehicle vibaration problem.For steel wheels/rail type vehicle, wheel tread profile plays an important role in dynamics performance, especially for70%low floor LRV. wheel tread is designedparticularly when bogies with two different running gears that is independent wheeland regular wheel-set installed on the same vehicle. Based on the optimization andexisting wheel tread design as well as the built up data from tread in service, thisarticle brings up contacting angle method which can be quickly optimized byMATLAB software.This method can reduce maintainmance cost for users bygenerating tread profiling according to track different worn out status in differentphases.