| Rail transit has become the main means of public transport in major cities,and more and more cities in China begin to build subway lines.It is particularly important to study the operation safety of subway tunnels under the joint action of vehicles and the operation conditions under various working conditions.In this paper,multi-body dynamics and finite element method are mainly adopted,and software such as SIMPACK and ABAQUS are used to establish the car-wire-tunnel rigid flexible coupling dynamics model,complete the simulation under various operating conditions,and some conclusions are obtained.Main research work:1.In this paper,SIMPACK and ABAQUS software are used for joint simulation to propose the establishment method and steps of car-wire-tunnel rigid and flexible coupling model,which provides a foundation for further research.The dynamic characteristics of the coupling system are analyzed and discussed by using the measured data and field investigation.2.When the subway train runs at a higher and higher speed,the vertical force of the wheel and rail of the vehicle gradually increases,and the force on the fastener also increases at the same time,especially when the train runs at a high speed of 70-80km/h.After 50,000-80,000 km of wear,the run-in between the wheelset tread and the rail is good,and the vertical force and wear of the wheel and rail decrease relative to the new tread.After the subway train runs 140,000 kilometers,the vertical force and abrasion of wheel and rail will increase greatly due to the increasing abrasion of wheel tread.3.Because of the piston effect,the vibration of the tunnel has gone through a process of small-range vibration,larger vibration and the tendency of vibration tends to be stable.The trend of rail vertical acceleration is basically the same as that of tunnel wall vibration,but the vibration amplitude is much larger than that of tunnel wall vibration.Through the analysis of the investigation results,the number of cracks in the lining is absolutely dominant,which shows that it is of more practical significance to study the causes of cracks.The ballast bed near the lower part of the rail has the greatest stress,which needs to be paid attention to and strengthened in the detection and maintenance.4.In a straight track with high interference track spectrum from Germany,running at a constant speed of 80km/h,the derailment coefficient in the middle of the tunnel is large,about 0.028,which is far from the safety limit and can fully meet the operation requirements.The wheel weight loss rate changes greatly with the change of working condition.For vibration statistics at different speeds,axle boxes can be better described by peak-to-peak values,and rail and tunnel can be described by RMS values.It can be seen from the analysis that the dynamic response of the tunnel is not suitable to use peak-to-peak value for evaluation.Peak-to-peak values can be used to evaluate the statistical characteristics of dynamic response of axle box,rail and tunnel with different operating mileage.Through the study of this paper,a certain conclusion is obtained,which is of certain significance to provide theoretical support for maintenance,maintenance and daily detection and monitoring of operating units. |
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