Research On Disease Diagnosis Of Ballastless Track Based On Vehicle-induced Vibration Responses

The emergence and sustainable development of ballastless track structural diseases will seriously affect the operation safety of high-speed railways,so it is of great engineering significance to carry out rapid detection and research on ballastless track injury diseases.When the track structure is diseased,the physical parameters inside the structure will change,so when the train passes through the diseased section of the road,the vibration response of the body and the parts of the track will also be different from the response when the track is intact,based on this,this paper intends to explore the feasibility of rapid detection of typical damage of ballast-free tracks based on numerical tests based on the analysis of vehicle-induced vibration response signals.The main research content is as follows:(1)Taking the CRTSII type plate ballastless track and the CRH2 harmony EMU as the engineering background,the train-track coupling dynamic model is established based on finite element software,and the vibration response of the body and ballastless track structure during the train operation is obtained through dynamic analysis,and the obtained response is compared with the normative limit and the relevant literature simulation or measured values,which verifies that the established train-track coupling model has a certain rationality.(2)Through numerical simulation of four typical damage types of ballastless track fastener loosening,track plate cracks,CA mortar layer emptying and support layer cracks,the sensitivity of the dynamic response of the track and the part of the car body to the track damage under each damage condition was compared.The results show that the vertical acceleration of the track plate in the track part and the vertical acceleration of the wheelset in the train part are the best test data for the vibration response of the track and the car body,respectively.The sensitivity of the vibration response of the track and wheel pairs to the damage is enhanced with the increase of the speed and the degree of damage,and the closer the position of the track vibration response measurement point to the damage location,the stronger the sensitivity to the damage.(3)In response to the effects of random factors on the sensitivity of vibration response in the car,the diagnosis and identification method of rail injury based on the weighted strategy and wavelet analysis is proposed,and the effectiveness of the four typical track structure damage verification methods is used.The research results show that the use of information weighted by multi sensor can more effectively enhance the strength of the damage signal and the negative impact of noise.Further adopt a wavelet analysis to achieve the identification and positioning of orbit injury under the conditions of a minority measurement point information.