Impact Of Temperature Force On Vehicle-induced Vibration Response Of CWR Track

Due to the restriction of fastener resistance and track bed resistance,CWR can not shrink freely.When the rail temperature changes,a huge temperature force will be generated in the long rail.When the temperature force exceeds the limit value,it will lead to accidents such as railway structure’s bucking,runway and rail breaking,threatening traffic safety.It is key to maintain the stable working state of CWR to monitor the temperature force state of CWR.At present,the used temperature force detection method represented by displacement observation pile method is commonly used in engineering practice,and the temperature force detection method based on vibration response is still in the research stage.But in fact,the vehicle-induced vibration response of track contains more comprehensive temperature force characteristics of CWR,so it is necessary to study the impact of temperature force on vehicle-induced vibration response of CWR.In this thesis,based on the track vibration response data,a variety of data processing methods were used to extract the temperature force characteristic index of CWR,and the impact of temperature force on track vibration acceleration and rail dynamic strain response was studied,and the characteristics were analyzed by random forest.The main research contents are as follows:(1)The finite element model of CWR was established.The wheel-rail force was obtained by UM software and loaded into the model to analyze the vibration acceleration response of the track.The results show that the model can meet the needs of dynamic analysis of ballasted track structure.(2)Based on track vibration acceleration data,the response data were analyzed from the frequency domain,time-frequency domain and vibration transmission characteristics,the impact of temperature force on track vibration acceleration was studied,and the characteristic indexes representing the temperature force of CWR were extracted.(3)Based on the dynamic strain response data of rail under train load,the response data were analyzed and processed from the perspectives of time domain and correlation.The impact of temperature force on the dynamic strain response of rail was studied.The regularity information which can reflect the temperature force was obtained,and the characteristic index was extracted.(4)The random forest algorithm was used to establish the evaluation model of temperature force characteristic index,and the temperature force characteristic index was analyzed to obtain the relative importance of temperature force characteristic index.