Research On The Mechanical Analysis And Key Technology Of Modern Tramcar Track Structure

Modern trams have become an important way to solve the problems of traffic congestion in medium and small cities, which won the favor of the world. Though its technology and operational characteristics are similar to the metro and light rail, it has unique characteristics. Currently, the design of domestic modern tram track structure refers to foreign applications or other domestic urban rail transportation, which is lack of pertinency, and needs to be studied systematically. The purpose of this paper is to discuss the key technology of design for modern tram track system. The main contents of this thesis are summarized as follows:(1) Establish static and dynamic calculating model of modern tramsA sophisticated modern tram wheel-rail contact model is established with ANSYS, while detailed ballasted track space model (mixed, non-mixed) and ballastless track space model with ABAQUS. A concept of solid elements is adopted during modeling, which can accurately simulate mechanical properties of the track system.A tram-track coupling dynamics model is also established with SIMPACK. In this model, the whole vehicle model contains detailed swing bolster, side frame, etc. This model can efficaciously reflect the performance of the vehicle, providing an effective way to analyze the modern tram track dynamics.(2) Research on the selection of modern tram rails and track geometry from the perspective of static and dynamicA comparison is made with60kg/m rail and59R2trough-typed rail from the perspective of static and dynamic, and two types of reasonable track rail cant are discussed separately. In addition, from the perspective of dynamics, the issue of70%low-floor tram in gauge widening curve area is studied. Analysis shows that:1)60kg/m rail is better than59R2groove track in mechanical properties;2) it is proposed that rail cant1:20be adopted for both two types of rail;3) For70%low-floor tram lines, curve area with radius less than150m needs to be widened.(3) Make a study on modern tram ballasted track structure designing methods and the reasonable value of key parametersAccording to the actual operation of modern tram ballasted track structure, a designing method is presented, and the reasonable value of key parameters is discussed. The recommendations are as follows:control the elastic modulus of the track bed within 90～140MPa; take the track bed thickness at300mm, up to350mm; track bed shoulder be no less than250mm; choose track bed slope as1:1.75; sleeper spacing be more appropriate at around0.65m.(4) Make a study on modern tram ballastless track structure designing methods and the reasonable value of key parametersAccording to the actual operations of modern tram ballastless track structure, the mechanical state of the track structure under different loads for the right of way for mixed and non-mixed is analyzed. Based on this, a method of non-ballasted track structure of different right of the way is proposed and the reasonable value of key parameters of the non-ballasted track structure of the non-exclusive right of way is also researched. Through the analysis, it is proposed that fastener stiffness be within the range of30～50kN/mm; mattress width be set to2.4～2.8m; track bed board thickness be0.28m at most; track bed board concrete strength using C35～C50is more appropriate.