Study On The Influence Of Torsional Characteristics Of Air Spring On Vehicle Dynamic

Compared with the trunk railway,the line of urban rail transit vehicle has many characteristics,such as curve section,small curve radius,short transition curve and so on,and the line condition is relatively poor;While the train speed is not high,but the short distance between stations,frequent start and stop;traffic density;Large capacity,light weight of the vehicle requirements;empty load difference.As an air spring system of suspension system,it has excellent vertical and horizontal stiffness characteristics,be able to adapt to metro operation requirements.Therefore,the two series of urban rail vehicles are widely used air springs.Many scholars at home and abroad have carried out a deep analysis and research on the vertical and horizontal characteristics of air spring,but they have not been related to the torsional characteristics of air spring and its influence on the dynamic performance of the vehicle.Based on that,in this paper,taking the air spring of a subway vehicle as the research object,the three direction model of air spring with vertical,horizontal and torsional stiffness is established,the two direction model of air spring with vertical and horizontal stiffness also is established.The influence of torsional characteristics of air spring on vehicle dynamic performance is analyzed,In order to provide some reference for the research of metro vehicle running safety and curve passing.Firstly,considering the fluid solid coupling,the arrangement of the cord layer,the characteristics of the hyperelastic material and the contact relationship,air spring model based on finite element software ABAQUS is established with dynamic display analysis.the calculation of torsion stiffness of air spring is compared with the test value,the maximum error is kept within 5%,therefore,the finite element model of air spring can simulate the actual working conditions.Based on this model,the relationship between torsional stiffness and internal pressure or torsion angle is studied,the calculated torsional stiffness and the rubber internal pressure is increased linearly,and the relationship between the torsion angle is quadratic function.Therefore,we can get the curve of air spring torsional characteristics,At the same time,the transverse characteristic curve of air spring is obtained,in order to study the influence of air spring three direction model on vehicle dynamic performance.Secondly,the dynamic model of metro vehicle is established by using multi-body dynamics software SIMPACK.Reference to the relevant literature,and considering the torsion characteristic curve of air spring using finite element analysis method of fitting out,based on AMESim,the three direction and the two direction aerodynamic model of air spring for metro vehicle are established,which can be used to analyze the influence of the torsional property of the air spring on the dynamic performance of the vehicle.Finally,the joint simulation interface between AMESim and SIMPACK is built,the dynamic performance of metro vehicle is calculated by the joint simulation,the three direction model and the two direction model are compared and analyzed.The results show that the three direction model can better simulate the actual working conditions.