Study On Contact Dynamics Characteristics Of Central Pin In Turning Frame Of The Dynamic Stability Vehicles

Central pin assembly system is connection equipment which is used for connecting frame and turning frame of the dynamic stability vehicles. It bears two main kinds of force:the weight of the vehicle and pulling force. The upside and downside spherical plain bearings are the most important parts in the central pin assembly system. Radial spherical plain bearings are used for standing pulling force and thrust spherical plain bearings for the weight. Thanks to the two bearings, turning and swing of the vehicle frame are realized, which is helpful for the vehicle to travel on all kinds of complex lines. The study on dynamic characteristics and response of the spherical plain bearings improves the theoretical of the central pin assembly system and paves the way for further study on the dynamic stability vehicles.In this paper, combine the finite element software ABAQUS, nonlinearity numerical solution of contact and equivalent stiffness solution for the spherical plain bearings are discussed in depth. First, study focus on two states of the dynamic stability vehicle:stability working (depending on periodical exciting force comes from stability equipment) and speed traveling (considering random vibration of orbit). Contact nonlinearity finite element analysis is applied to the spherical plain bearings by constructing finite element model based on the software. The contact problem of the bearings'inner and outer race is converting to unclassical contact mechanics problems. Nonlinearity contact theory is used as a direct method to analyses dynamic characteristics and response of the central pin assembly system. A second, equivalent stiffness analysis is applied to the spherical plain bearings. Equivalent stiffness finite element dynamics analyses model of two states of the vehicle is constructed. Many spring elements are set between inner race and outer race of the spherical plain bearings according to spring principle. Contact relationship between inner race and outer race is reflected by value of equivalent stiffness and damping. Dynamic response analysis results on the spherical plain bearings are obtained by putting on working load. Equivalent stiffness method, which as a new method is put forward for large-scale system dynamics modeling, realizes contact dynamic characteristics converting of the central pin assembly system.Results show it is feasible that direct access to contact nonlinearity numerical method and equivalent stiffness method are used in dynamic analysis of the central pin assembly system, which is in stability working and speed traveling. Contact nonlinearity numerical method can simulate real working environment. But it's difficult to model and time consuming in compute process. It is not suitable for large-scale system dynamics modeling. While equivalent stiffness method makes modeling more simple and efficient. The output parameters of responses such as displacement, velocity and acceleration are in line with analysis results of contact nonlinearity numerical method. So equivalent stiffness method is more suitable.