Study On Dynamic Coefficient Of Metro And Ptimization Of Track Parameters

As an underground transportation system in urban rail transit,the subway which is quick convenient,and eco-friendly has greatly eased ground traffic congestion.A car,as one of the most frequently used the subway models,is based on its track structure characteristics and reasonable selection of track structure characteristics,which is not only improve the dynamic performance of the subway,improve the vehicle's operating stability,but also extend the operation life of the subway components.Based on the vehicle-track coupling dynamics,this paper builds a 3D model of the vehicle-track of the subway A by means of the dynamic simulation software UM(Universal Mechanism).Under different operating speeds,fastener stiffness,and track bed rigidity,Dynamics index such as the body wheel pair acceleration,wheel-rail vertical force,rail vertical acceleration,track bed vertical acceleration,wheel weight reduction,load factor and derailment coefficient are analyzed.Research indicates that:(1)The wheel-rail vertical force calculated by the American fifth-level spectrum as the irregular excitation simulation accords with the normal distribution,while the second wheel-rail lateral force doesn't,and the overall distribution of the density curve is similar to the normal distribution.(2)When the driving speed increases,the average value of wheel-rail vertical force does not change;when the standard deviation and coefficient of variation get larger,the average value of lateral force becomes larger,and both of the standard deviation and coefficient of variation get larger.(3)When the driving speed is constant,the energy transfers which between the wheelset and the rail,and in the midst of the rail and the track bed are obviously higher than that in the high-frequency region.(4)Under the condition of analyzing the vertical force distribution of the wheel-rail,this paper proposes that the vertical dynamic coefficient would be set as 1.13 and the lateral force dynamic coefficient would be set as 0.039 when the design speed is 100km/h.(5)Through the sensitivity coefficient analysis,when the stiffness ratio changed,the stiffness of the fastener is not supposed to take less than 30 kN / mm.At the same time,the analysis shows that the optimal vertical stiffness of the fastener is 50 kN / mm,and the optimal vertical stiffness of the track bed is 180 kN./mm and 200 kN/mm.