Study On Dynamic Characteristics And Evaluation Method Of High-speed Turnout In High-speed Railway

High-speed railway transportation is playing a more and more important role in China’s transportation system.As an important fixed equipment of high-speed railway,the turnout is also the top priority of the maintenance of equipment management units.Due to the complexity of the structure and wheel-rail relationship of the expressway turnout,the damage caused by the high-speed train impact mainly focuses on the following aspects: the over-size of the track geometry,the reduced value of the sharp rail and the core rail exceeding the standard,the excessive clearance of the joint of power and power,the side wear of the sharp rail and the loosening and fracture of the connecting parts.Problems such as track geometry size,clearance,rail surface damage,connecting parts and signs of expressway turnout can be found and dealt with by traditional maintenance quality assessment or manual static inspection,but it is difficult to check and evaluate the performance of the turnout in passing state.Based on the data of track geometry and axle box acceleration,the dynamic characteristics of the train can be analyzed,and the comprehensive performance of the passing state can be evaluated scientifically.Then,using the evaluation results to scientifically and reasonably prepare annual and monthly maintenance plans to realize the combination of comprehensive maintenance and single disease control,which is conducive to the normal maintenance and balanced improvement of turnout equipment quality,and has a very important significance for the control of the optimal goal of cost.Short-wave and medium-long wave diseases in the turnout area are the key factors affecting the safety,stability and stability of trains,and the dynamic response data such as axle box acceleration,carriage body lateral acceleration,carriage body vertical acceleration and frame transverse movement are the core of the key factors.Through the time-frequency analysis of the dynamic data collected from the comprehensive inspection train,the correlation between the axle box acceleration,the lateral acceleration of the car body,the vertical acceleration of the car body and the transverse movement of the frame and the static disease of the expressway switch is explored respectively.Through a large number of data analysis and field review,it is found that turnout joints,rail abrasions and wave abrasions are the key factors affecting axle box acceleration.High and low irregularities have a great influence on the vertical acceleration of the car body,and rail irregularities are the core factors affecting the lateral acceleration of the car body and the transverse movement of the frame.Through to train a bifurcation of the short-time Fourier transform and the dynamic response data processing,the axle box vertical vibration acceleration,the lateral and vertical acceleration of the body of the time-frequency distribution,obtained the frequency of axle box acceleration and the corresponding switch shortwave diseases,to verify the use of rail impact index(TII)to evaluate the feasibility of the short-wave disease,The main frequencies of lateral acceleration and vertical acceleration and the corresponding medium and long wave diseases of different wavelengths were obtained,and the feasibility of using weighted composite index(WCI)to evaluate medium and long wave diseases was verified.On the basis of the comprehensive analysis,the comprehensive performance evaluation of turnout state including short-wave and medium-long wave diseases is carried out by the analytic hierarchy process.Finally,the switch unit management and maintenance task formulation are optimized by using the results of the switch state comprehensive performance evaluation.Proposed by judging the orbit of short-wave disease impact index(TII)and evaluation of long wave disease weighted composite index(WCI)by switch state comprehensive index(TPCI),and to judge the through the state of the switch.The practicability of this method is verified by the static disease and rechecking of No.18 turnout.In this paper,the research achievements of maintenance and cost control of the high-speed rail has strong guiding significance,and also provide scientific data support for the dynamic unit management of turnouts and the formulation of annual production plans,monthly maintenance tasks and weekly maintenance priorities.In addition,the results have strong reference significance to the comprehensive evaluation of the passing state performance of ballast turnout.