Analysis Of The Longitudinal Force Of Single Seamless Turnout Of Slab Track On Bridge

Seamless switch is a key technology of Cross-CWR that can significantly increase the function of switch operation and maintain smooth and comfort operation of the train in high speed. Therefore, it is a switch domestic and international issues of concern to study the design method of seamless switch. It has important practical significance to improve the design theory and method of seamless switch on slab track and bridge, which make theory calculation and analysis of this structure and study the effect of the value of various parameters to structure design.In this paper, the three-dimensional solid model is established by using ANSYS finite element software, rail use beam element to simulate, rail board use solid element to simulate, fasteners, spacing iron, limit and block units use spring element to simulate, bridge board use solid element to simulate, elastic support use solid element to simulate.With the help of finite element model, following studies are done in this paper:(1) With the role of temperature force, this paper analyzes the force and deformation of bridge and seamless switch and obtains the general law of force and deformation of seamless switch on bridge;(2)With the calculation, this thesis analyzes the main factors to effect the force and deformation of single seamless switch on bridge:changes in rail temperature range, resistance of fastener, stiffness of convex setting block, stiffness of support and span of bridge, and obtains the law of force and deformation of single seamless switch on bridge with the effects of these factors;(3)The thesis select the braking force for load conditions, calculate the force and deformation of the structure with the different loading condition, and obtains the law of force and deformation of switch and bridge with the different loading condition, which helps to obtain the reasonable suggestions for optimizing the structure.Through calculation, changes in rail temperature range greater impact on the force of the structure, but it generally do not cause structural damage. The stiffness of fastener of basic rail has great effect in the structural force and has little effect in the displacement of tip rail and heart rail. The stiffness of fastener of rail in switch zone has great little in the structural force. Resistance of fastener of rail in switch zone will cause the smaller displacement of tip rail and heart rail but will increase the interactive force of beam and rail, so with meeting the conditions required by for switch, resistance of fastener may be as small as possible in order to reduce the interactive force of beam and rail. The increase of stiffness of convex setting block is benefit of keeping stable structure but will increase the interactive force of beam and rail, so various factors should be considered to determine its value.The stiffness of support has little effect in the structural force of switch. Span of bridge has great effect in the structural force and displacement. Big span of bridge is bad for the structural force and stability.Under the action of the braking force, the force from four load conditions have pair symmetry. It is small that the displacement of tip rail and heart rail be caused by the braking force and will not exceed the restraint. The maximum stress from the braking force occurred at the interface between the bridge and roadbed. The interface between the bridge and roadbed may set transition section in order to enhance the life of rail.These results from this paper is a guiding significance for theory study and construction and design of seamless switch on bridge.