Research For 100% Low Floor Rail Vehicle’s Dynamic Performances

Since the 1980s,low floor light rail vehicle has been booming,it has not only enriched the people’s traveling choices and relieved the traffic pressure,but also made a great contribution to the urban environment. The low floor light rail vehicle is a kind of environmentally friendly transports which uses electric traction. With various forms and beautiful shapes,it has become a bright scenery among the urban landscape. The technology of low floor light rail vehicle is still at the initial stage in our country,and has broad development space and potential market.With the reference to the bogie projects in"Research for a Low Floor Railway Vehicle Bogie Scheme with Small Diameter Wheel"and relevant literature both at home and abroad,a kind of 100% low floor light rail vehicle was established by the multi-body dynamics analysis software SIMPACK,then its dynamic performances were analyzed in detail,the work was done by the following:1.According to the vehicle’s structure,the force analysis of different car bodies in static balance state were carried out, then the static loads of the connection hinges were worked out on the basis of the static equilibrium equations,and the nominal forces of the hinges in the model were almost equal with the theoretical value,so the set of the hinges between car bodies were reasonable.2.The influence of suspension parameters on the vehicle’s stability, ride comfort and curving passing ability were analyzed,including the primary suspension stiffness,secondary suspension stiffness,the damping of the secondary lateral/vertical shock absorber and the damping of the longitudinal shock absorber between car bodies.The results showed that the primary suspension stiffness has great influence on the vehicle’s stability and curve passing ability.The secondary suspension stiffness has great influence on the vehicle’s stability and ride comfort.The damping of the secondary lateral shock absorber has an effective impact on improving the vehicle’s stability,ride comfort and curve passing ability,while the damping of the secondary vertical shock absorber mainly affects the vehicle’s ride comfort. Additionally,the damping of the longitudinal shock absorber between car bodies has little influence on the vehicle’s dynamic performances,while once it is canceled, the vehicle’s lateral ride comfort and curve passing ability at low speed will get worse.3.According to the analysis results,the vehicle’s suspension parameters got optimized,then its dynamic performances were studied again in unloaded and loaded conditions.The results showed that after optimization the vehicle’s critical speed could meet the demands of the top speed 80km/h,and has enough safety margin.After optimization the vehicle’s ride comfort has been improved a lot,especially its lateral ride comfort.After optimization when the vehicle operates at the speed of lOkm/h through 50m radius curve, at the speed of 20km/h through 100m radius curve, at the speed of 40km/h through 200m radius curve, at the speed of 50km/h through 300m radius curve,its dynamic indexes on curve track can meet the relevant standards in GB5595-85 no matter in unloaded condition or loaded condition.