Study On Joint Forces' Sensitive Parameters Of 100%Low-floor Trains

As an important part of urban rail transmits,100%low floor tram is in the ascendant.Multi-articulated 100%low floor tram becomes the main form of it because of its low cost,easy to group and modular design.The connections between different modules are accomplished by articulated devices.Structural design of articulated devices and parameter selection has important impacts on the vehicle service quality and safety.Therefore it is of engineering guidance significance to study on the influence factors of the distribution of the joint force.The first chapter introduces the research significances,research status at home and abroad and main research contents of this paper.The second chapter introduces the technical route and finite element model and mathematical model of the study objects.The third chapter mainly discusses how the centroid positions of each module influence the distribution of the joint force.Results shows that the centroid positions of each module has significant influence on the joint force distribution,while under different grouping form and load cases,those position parameters have different influence rule on the joint force distribution.Each force changes monotonously with the change of centroid position parameters and satisfies the equilibrium conditions.The forth chapter mainly discusses the influences of joint stiffness on the distribution of joint forces.Results are as follows:(1)Under different load cases and group forms,the influence on the distribution of the joint force varies due to the stiffness change of one direction;For the three module group,the change of the stiffness has nothing to do with the joint force if the direction of the stiffness isn't parallel to the joint force;Compare to the upper longitudinal joint force,the lower longitudinal joint force is more sensitive to longitudinal stiffness;(2)For the five module group,the existence of upper open joint makes the longitudinal force mainly taken by the lower joints.So in spite of the stiffness change under all load cases,the joint forces keep unchanged.(3)The group form of seven module group is similar to the five module group.so the joint force change under the same rule;(4)Regardless of group difference,when the lower joint stiffness of is larger than 1E4N/mm,the joint forces keep unchanged when the stiffness continue to increase;(5)Regardless of group difference,changing vertical stiffness of lower joint has nothing to do with the vertical force of lower joints;Finally this paper develops a program for calculating the interface position load of 100%low-floor light rail vehicle by using VB software.This program can calculate the inter-forces of three,five and seven group.