A Study On Dynamics Of Ballastless Turnout On Bridge Of High-speed Railway By Co-Simulation Of Rigid-Flexible Coupling System

High-speed railway in our country has come out with the feature of large scale application of ballastless track and bridges in order to insure high regularity. With the development of high-speed railway, turnouts have been set on bridges. The vibration caused by structural irregularity of ballastless turnout on bridge, combined with vibration of bridge, make the dynamic features complex. Stiffness irregularity is existed in transition of ballastless turnout and normal ballastless track on bridge, thus the running safety and comfort and service life of turnout are affected negatively.In this paper, in order to study dynamic behavior of ballastless turnout on bridge and transition of turnout and normal track, a rigid-flexible coupling system model of vehicle, turnout and bridge is established by co-simulation of SIMPACK and ABAQUS, based on the multi-body dynamic theory and vehicle track coupling dynamic theory. The model is certified available comparing to past research work. A new effective simulation method is offered for dynamic analysis of vehicle-turnout-bridge system.Dynamic behavior of ballastless turnout on bridge under the condition of high-speed vehicle passing through turnout are studied from the views of wheel rail interaction force, running safety and comfort, dynamic behavior of turnout, and dynamic behavior of bridge by using the rigid-flexible coupling vehicle-turnout-bridge model. When vehicle passing through switch rail and cross rail, impacts occurred between vehicle and turnout. Interaction forces and vibration of turnout are magnified. Running safety and comfort, and deformation of structures are satisfied with the standards.According to the rigid-flexible coupling model, a modified model for dynamic analysis of transition is established. The dynamic behavior of transition of turnout and normal track on bridge of high-speed railway is analyzed with the modified model. The influence law of running direction, relative position of turnout and bridge, stiffness difference, and running velocity are analyzed. The transition method is designed and analyzed, and available design of gradational transition is suggested. The gradation length is suggested to use the length of element track slab for construction convenience.