The Research On Influence Of Wheel Load Deviation On The Running Performance Of Three-axle Frame-type Bogie Wagon

With the rapid development of China’s economy and the implementation of a series of policies for optimizing the structure of freight transportation such as "return to rail",railway freight has ushered in unprecedented development opportunities.As an important means to improve the efficiency of railway freight transportation,heavy-haul transportation has become the main development direction of railway freight transportation in the world.Heavy-haul transportation is mainly achieved by multimodal transportation,increasing the axle load of vehicles and increasing the number of axles of the vehicle,but the multimodal transportation and increasing the axle load of vehicles are subject to the limits of the existing line conditions and loading goods,especially some special wagon loaded with large equipment have been difficult to meet the loading requirements only by increasing the axle load.Therefore,the multiaxle bogie can be used to improve the carrying capacity of the bogie,thereby increasing the load of the vehicle.In addition,for multi-axle bogie vehicles,the impact of wheel(axle)load deviation on its running performance is more complicated and has not been studied in detail.Therefore,this paper conducts a study on the effect of wheel load deviation on the running performance of three-axle frame-type bogie wagon.Firstly,the development of railway freight transport in China and the development and research process of heavy-haul freight transport technology at home and abroad are discussed,and then the research status of multi-axle bogie freight vehicles at home and abroad is introduced.Then,the structural characteristics and main technical parameters of the three-axle frame-type bogie wagon are introduced in detail.Based on the multi-rigid-body and rigid-flexible coupling dynamics theory and modeling method of the vehicle system,through reasonable assumptions and simplifications,and using SIMPACK and ANSYS software,the multi-rigid-body vehicle dynamics model and the dynamic model of the three-axle frame-type bogie wagon considering the flexibility of the frame under the empty and loaded vehicle conditions are established.According to the GB/T5599-2019 locomotive and vehicle dynamic performance evaluation standard,different simulation analysis test lines and operating speeds suitable for the three-axle frame-type bogie wagon are set.Secondly,the theory and calculation method of the vehicle hunting stability,lateral stability,comfort and curve passing safety are introduced,and the dynamic performance of multi-rigidbody and rigid-flexible coupling dynamic model under empty and loaded vehicle conditions is calculated by simulation.The calculation results show that the stability,comfort and curve passing safety of the three-axle frame-type bogie wagon under empty and loaded vehicle conditions meet the requirements of GB/T5599-2019;Frame flexibility has little effect on vehicle stability,comfort and curve passing safety;and the performance of loaded vehicles is better than that of empty vehicles.Furthermore,the simplified mechanical model of four-point and eight-point plane support is used to analyze the influence of side-bearing failure on vehicle wheel load distribution,and the influence of side-bearing failure at different positions on vehicle dynamics performance is further studied.The calculation results show that the complete failure of each single side-bearing has a great impact on the running stability of loaded vehicles and the comfort and curve passing safety of empty vehicles.The failure of side-bearings has the most obvious impact on the wheel load reduction rate of the vehicle.The front side-bearings failure of front bogie have a great impact on the vehicle curve passing safety.When the plane degree of the side-bearing support surface is within 0.6mm,the vehicle can safely pass the small radius curve.Finally,according to Railway cargo loading reinforcement rules,the influence of the lateral deviation of vehicle gravity center on the wheel load deviation and the influence of the wheel load deviation caused by the lateral deviation of the freight on the running performance of the vehicle are studied.The research results show that a certain wheel load deviation leads to the decrease of the hunting stability and comfort.It is recommended that the wheel load deviation caused by the deviation of the freight center of gravity of the three-axle frame-type bogie wagon should be controlled within 25% to ensure that the running safety of vehicle.