The Research Of Ideal Curved Surface Configuration Of Straddle Monorail Vehicle

Through the investigation of actual operation of Chongqing monorail line 3,it can be seen that there is a serious uneven wear of tires when the straddle monorail vehicle travels about 70,000 kilometers later.Due to the uneven wear of tire,the adhesion ability between wheels and track beam at contact surface is abruptly reduced,which makes the driving efficiency of the vehicle drop and increases energy consumption.at the same time,resulting in adverse effects of low braking efficiency.To a certain extent,it reduce the vehicle running stability and energy saving.In order to solve this problem,the concept of "ideal walking surface" is proposed with reference to the optimization of tread shape of railway vehicles and automobile wheel alignment.It is intended to balance the additional lateral force through the adjustment of the track surface shape to achieve wheel-rail coordination and reduce the uneven wear of tire.Using BP neural network and the genetic algorithm,the "ideal traveling surface" of the curved track beam is constructed based on the reduction of the uneven wear of tire.The technique of quadric spline interpolation is used to fit cross-section curve function of the track beam,which make the ideal walking surface tangible.In this paper,not only carry out the dynamic performance analysis of monorail vehicle under the curved surface,but also lay a theoretical basis for innovative design of track beam.The main research contents are as follows:(1)Based on the analysis of the wheel and track force caused by the tire wear,it is found that the combined effect of slip angle and roll angle is the main disadvantage of tire uneven wear and define the way to drop uneven wear is to reduce the lateral force.According to the theory of multi – body system dynamics,the simulation model of single monorail“Track-Tyre-Vehicle”is established in MD ADAMS software.(2)The BP neural network and the genetic algorithm are used to adjust the shape of the ideal of track beam which can realize the wheel and track beam coordination.And then by means of quadratic spline interpolation,the shape of "ideal walking surface" is tangled,and obtain the cross section of the track beam is concave curve equation,which can reduce the tire wear.(3)In order to realize the feasibility of PC track beam and the industrialization of manufacturing,the cross section curve of ideal curved surface track is fitted intoconcave elliptic curve,circular curve and trigonometric curve respectively.From the perspective of wheel and rail force,in this paper analyses the degree of uneven wear of tire under three kinds of surfaces.By comparing evaluation factor index of tire to obtain the circular curve of the track beam can greatly reduce lateral force.(4)Under the good condition of wheel-rail contact relationship,the key guarantee for the normal operation is the monorail vehicle dynamic performance.A series of simulation analysis of the monorail vehicle dynamics under the ideal running surface is carried out,which involved four aspects that wheel-rail action force,the operation safety performance,comfort of the curve and curve through performance.