| With the accelerating of urbanization process,urban rail transit has become the main direction of transportation development in large cities in China because of its characteristics of large passenger capacity,safety and reliability.Good comfort is the basic requirement of passengers when taking urban rail vehicles.On the premise of ensuring efficient operation,improving comfort is of great significance to improve the transit service quality of urban rail vehicles.From the aspect of vibration comfort,the longitudinal impulse generated by line factors,traction and braking during the operation of urban rail trains makes passengers feel frustrated during daily commuting,which affects the riding experience.At the same time,in order to meet the requirements of lightweight,the car body structure usually uses new materials such as aluminum alloy,which reduces the stiffness of the car body structure so that the multi-body dynamic model can not reflect the real vibration of the vehicle.Therefore,it is necessary to explore the influence of longitudinal impulse on the riding comfort of urban rail vehicles on the basis of considering the elastic characteristics of car body.In this paper,through the modal analysis and substructure analysis of the finite element model of the car body of a type B metro motor car,the relevant documents required to generate the elastic car body are obtained.Based on the relevant parameters of the metro motor car and trailer under full load condition,the multi rigid body train dynamic model and the rigid-flexible coupling train dynamic model considering car-body elasticity of the single vehicle are established in multibody system dynamic simulation software,SIMPACK.Taking GB / T 5599-2019 as the evaluation standard of riding comfort,the influence of the elastic characteristics of the car body of motor car on the riding comfort is explored by analyzing and comparing the calculated results of the comfort values of three measuring points on the floor of the elastic car body and the rigid car body which are located on different sides of the center of front and rear bogies and under the inner seat in the middle of car body under the idling condition of straight line with different running speeds,The results show that considering the elasticity of the car body makes the comfort value of the measuring points at different speeds increases by 17.9% to 327.6%,and the calculation results of the comfort value of the middle measuring point on the floor of the elastic car body are affected by the elastic characteristics of the car body,which show the trend of increasing first and then decreasing with the increase of speed.On this basis,the influence of longitudinal impulse on the riding comfort of elastic urban rail vehicle is explored by setting the idling conditions of different lines and the traction or braking conditions under different lines.The results show that the longitudinal impulse generated under the influence of traction force,braking force and additional resistance from the line increases the comfort value of elastic urban rail vehicle by 11.9% to 146.2% at most.At the same time,because of the elastic characteristics of car body,the influence of longitudinal impulse on the comfort of the front and rear measuring points is increased and the middle measuring point on the floor of the elastic car body has a negative growth change when traction and braking on the straight line.From the analysis of the comfort values,it can be seen that the influence of longitudinal impulse on the riding comfort of urban rail vehicle should not be ignored,and it is necessary to consider the elastic characteristics of car body when exploring the influence of longitudinal impulse on the riding comfort of urban rail vehicle.The analysis results have certain significance and reference value for improving the comfort of urban rail vehicles. |
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