| Steel spring floating slab track because of its excellent vibration damping effect is widely used in rail engineering,under the repeated action of train load,steel spring isolator may fail the situation,adverse effects on the infrastructure,serious will endanger driving safety,so it is meaningful to study the impact of floating slab track steel spring failure on the dynamic response of the rail system.In this thesis,taking the prefabricated steel spring floating slab track as the research object,ABAQUS software and SIMPACK software are used for joint simulation,a three-dimensional finite element model of vehicle-floating slab track coupling is established,the modal analysis of the floating slab track is carried out,the influence of parameter changes on the natural frequency of the floating slab track structure is analyzed,and the influence of steel spring failure on the vibration characteristics of the rail under different working conditions is discussed in detail.The main research contents of the thesis are as follows:ABAQUS finite element software is used to establish the finite element model of prefabricated floating slab track,and the modal analysis of the floating slab track structure is carried out,the natural frequency and mode shape of the structural system are given,and the influence of ballast parameters on the natural frequency of floating slab track is analyzed in detail.The results show that the change of fastener stiffness has little influence on the natural frequency of floating slab track.The natural frequency of slab track increases with the increase of steel spring rate,and decreases with the increase of thickness,density and length of floating slab.Based on ABAQUS-SIMPACK joint simulation,the simplified finite element model of floating slab track is imported into SIMPACK software through substructure analysis,and the rigid-flex coupling method is used to establish a coupling relationship between the train model and the floating slab track in the form of multiple rigid bodies,and the American six-level power spectrum excitation is applied to the track model to obtain the vehicle-floating slab track coupling dynamic model,and each spring breaking condition is established.Study on the influence of failure of different number of steel springs on the dynamic response of railroad system.The results show that the vertical acceleration of bogies,vertical acceleration of rails,vertical acceleration of floating slabs,vertical displacement of rail and vertical displacement of floating slabs increase with the increase of the number of steel spring failures,and when the number of steel spring failures reaches 4,the vertical displacement of the rail reaches 4.03 mm,exceeding the specification limit;when the number of steel spring failures reaches 5,the vertical displacement of the floating slab reaches 3.12 mm,exceeding the specification limit.Therefore,when the number of steel springs fails is large,it should be repaired or replaced in time.Study on the influence of steel spring failure at different positions on the dynamic response of rail system.The results show that when the number of broken springs does not exceed 3,for the vertical acceleration of bogies,vertical acceleration of rails,vertical acceleration of floating slabs,vertical displacement of rail and vertical displacement of floating slabs,the position of broken springs has a greater influence on the end of the slab than in the slab.When the number of broken springs exceeds 3,the more concentrated the distribution of failed steel springs,the greater the influence on the vertical acceleration of the bogie,the vertical acceleration of the floating slab and the vertical displacement of the floating slab.For the vertical acceleration and vertical displacement of the rail,the influence of the steel spring on the track side is greater when it fails completely.When it is serious,the steel spring should be monitored in time and the failed steel spring should be repaired. |
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