Influence Of Local Temperature Change On Longitudinal Mechanical Characteristics Of Rail In Continuous Welded Rail

The CWR technology is recognized and developed by all countries in the world.However,in the summer hot season,there will be a large temperature force in the continuous welded rails,which will easily lead to the instability of the rails and endanger the safety of driving.When the rails are in a critically swelled state,local cooling is one of the common emergency measures.It can reduce the temperature of the rail by water or liquid carbon dioxide.As a result,the longitudinal force is reduced and the railway is restored to normal.However,at present,there is no deep study on the range and effect of longitudinal force dissipation after local cooling of rails.In addition,after the local cooling of the rails,the temperature of the rails will rise again.Due to the elastic-plastic characteristics of the ballast resistance,the contraction displacement may still exist.As a result,there will be a temperature stress peak in the rail.To solve these problems,the following research has been done.(1)Based on widely collected relevant research data of the local cooling method,this paper makes deep exploration of it from theoretical research and practical application.And then combined with the research status and daily maintenance work,the existing problems of local cooling method are pointed out.(2)The ballasted track is simplified and the calculated mechanical model is obtained.Then,based on the strong modeling capability of ANSYS software,a finite element analysis model for the local temperature variation of the continuously welded rail track is established.At the same time,the parameters in the model are selected,and the rail length,constraints,and load of the calculation model are discussed and analyzed.(3)Through finite element analysis,the influence of the change in local rail's temperature on longitudinal mechanical properties of rail is studied and analyzed.Then the longitudinal force distribution and longitudinal displacement trend after changing the local temperature are mastered.Based on this,analyze the changes in longitudinal mechanical properties under different temperature-variable intervals,temperature range,and longitudinal resistance further,and put forward some corresponding suggestions.