| Due to the factors affecting structure accomplish the function of uncertainty and random factors on the impact of engineering structure has become an integral part of the structure design.The material parameters,geometric parameters and structure parameters in the urban rail transport system discreteness are random,and rail transit vehicle and track system response depends on the parameters matching,so the research of orbit parameters influence on dynamic response of transition section is of great significance.This paper established a relatively perfect train-steel spring floating slab transition section model of dynamic analysis,and used the reliability analysis method and he track-steel spring floating slab transition section of dynamic analysis as the foundation.This paper studied the transitional period of rail deflection rate control targets,and analysed the different transition section scheme evaluation.The main research results are as follows:(1)A relatively complete the analysis model of dynamic transition section is established.The actual layout of steel spring and different slab shear hinge settings,such as fine modeling,are taken into account in the model.And the model is verified by spectrum characteristics of steel spring.(2)Through the analysis of slab track on the basis of modal parameters fall,the natural frequencies and corresponding mode shapes of the floating slab track are obtained.This paper analyzes the three aspects of the dynamic response of the vehicle body,the wheel rail force and the track dynamic response of the subway train passing through the transition section of the steel spring floating slab track from the point of view of traffic safety and comfort.The dynamic wheel load reduction rate and the vertical acceleration of the vehicle body are obtained,but also the characteristics of the force spectrum of steel spring and the force characteristics of the fastener in the transition section are obtained.From the damping effect analysis of floating slab track vibration characteristic calculation shows that:The floating slab transition body maximum vertical acceleration 0.051 m/s2 and maximum wheel load reduction rate of 0.0084,can meet the driving comfort and safety requirements;The steel spring connection force first three frequency distribution meet the basic law of = v/La,f1 = 2f0,f2 = 3f0;These meet the requirement of vibration reduction:Z level of vibration damping effect of floating slab track(FST)is 16.1 dB,maximum difference frequency vibration level is 17.4 dB,the minimum difference of 13.2 dB,vibration acceleration vibration differential value of 17.0 dB.(3)Using reliability analysis method and combining the reliability failure probability analysis of track transition section parameter randomness for rail deformation control index,the effects of proposed targeted rail deflection rate maximum recommended limit is 1.17 mm/m.And further check:to recommend the rail deflection rate transition control limit when the stiffness difference and track irregularity unfavorable combination under the comprehensive action of traffic safety indicators meet the standard requirements;according to the recommended value of control index of different design schemes of rail deformation,the transition section was evaluated when the working set for the first three rows of steel the spring fastener spacing arrangement,the first row of steel spring for spring 4 encryption to enhance the rigidity of the two row of the 2 normal steel spring,and the remaining two times with steel spring fastener spacing layout,to meet the rail deflection rate control index. |
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