Research Of Dynamic Characteristics Of CRTSâ…  Ballastless Track On Bridge

With the rapid development of high-speed railway industry in the world, ballastless track has been promoted greatly as a new type of structure. Compared with the traditional ballasted track structure, ballastless track has several advantage such as better structural stability, better structural durability, better track regularity,better stiffness uniformity,less maintenance and relative mature of technology.Nowadays,China is committed to developing high-speed rail and pay attention to the construction and operation of high-speed heavy railway and passenger line. The traditional ballasted track has been unable to meet people’s demand for high-speed,so in-depth study of the structural properties of the ballastless track track come to be very necessary.In this paper, ABAQUS finite element analysis software will be used to establish the vehicle-CRTSâ… slab ballastless track-bridge model,and dynamic performance of this system will be evaluated with related indicators, the specific contents are as follows:1.An Introduction of ballastless track structure and wheel/rail dynamics at home and abroad has been made as the background of this paper.2. An Introduction of vehicle-track-bridge has been made to provide a theoretical basis for establishing the finite element model later.3. ABAQUS/Expilcit has been used to establish vehicle-track-bridge space model to go on the dynamics simulation analysis with the dynamic performance evaluation. By analysising this model we know, the suspension system in the vehicle model plays an obvious damping effect to reduce the acceleration from wheel to bogie and body;so is the fastener,that acceleration reduces a lot from steel rail to track plate to avoid violent vibration of the track plate; CA mortar layer has small elastic modulus so that acceleration reduces much less from track plate to base plate.It is propitious to disperse the vibration and deformation and transfer it to the substructure. From the viewpoint of dynamic performance evaluation of vehicle and bridge, maximum vertical and lateral acceleration of the vehicle body is 0.074 g and 0.089 g,and it is less than vertical and lateral acceleration riding index 0.13 g and 0.10g; maximum vertical and lateral acceleration of the bridge is 0.166 g and 0.111 g, and it is less than vertical and lateral acceleration limit value 0.50 g and 0.14 g. Bridge deflection and lateral amplitude is 0.893 mm and 0.395 mm,and it is less than the limit value 21.3mm and 1.939 mm.4. Analysis the influence of fastener stiffness and damping, track plate and base plate elastic modulus to dynamic characteristics of the track structure,and offer the recommendations of reasonable value to the parameters: fastener stiffness is 70kN/mm~90 kN/mm; fastener damping is 50 kN ï¹' s/m~70k N ï¹' s/m; track plate elastic modulus is 30000MPa~40000 MPa; base plate elastic modulus is 25000MPa~30000MPa.