The Numerical Simulation Of Preflex And Cooling Process Of U75V 100-meter High-speed Heavy Rail Before Straightening

With the rapid development of our national economy, the railway is regarded as the artery of the national economy, the "bottleneck" limit function is become increasingly obvious, railway must carry out span type develops to break the "bottleneck" limit of railway transportation as soon as possible. The manufacturing of heavy rail using in high speed railway is the basic guarantee of the national economic construction and social sustainable development. the analysis of the rail deformation after rolling during cooling process has great significance on improving rail product precision and high-speed trains running smoothness.This paper using large-scale finite element analysis software ANSYS establishs preflex and cooling process numerical simulation model of U75V heavy rail, mainly numerical simulate the straight rail cooling process, the straight rail cooling process in different initial conditions and the rail cooling process in different preflex rules respectively, and deeply analysis temperature field distribution rule,bending deformation rule,residual stress distribution rule and section size changing rule under different environment conditions and different preflex conditions.Through the analysis of the results, several outcomes can be learned, the temperature difference of rail section achieve maximum when rail has been completed phase transition, which avhieve minimum in final cooling time. Heavy rail natural cooling sumulation experience bent to rail base—bend to rail head—bend to rail base—bend to rail head reciprocating bending process, which is complicated in the phase transition stage, and the whole rail bend to head in final cooling time, Preflex rail also experience changing the same as the natural cooling process, and the whole rail in final cooling time close to flat. The initial temperature increase along with the residual stress in the center of rail base in the final cooling time increaseing. The changing rate in each part of rail section size is more than 1.3% after cooling. This paper can provide the theory basis and the advisory opinion on the formulation of cooling technological parameters and preflex regulations of the rail.