The Influence Of The Operating Line Condition On The Dynamic Performance Of The 30t Axle Load Heavy-Haul Train

Heavy-duty railway transportation,due to its high transport capacity,efficiency,low energy consumption,and transportation cost,has been widely recognized by countries around the world.Especially in China,a large continental country with vast territory and uneven distribution of resources,the development of heavy-duty railway transportation is of great significance.However,the contradiction between railway transport volume and transport capacity in China has long been unresolved.To develop the transport capacity of heavy-duty railways,our country has increased the axle load of freight cars to improve the transport capacity of heavy-duty transportation.However,the increase in transport capacity is severely restricted by the bridge,rail,ballast,roadbed,welding joints,and corresponding track diseases,especially for heavy-duty transportation.Therefore,exploring the effect of extreme operating line conditions on vehicle-track dynamic performance,knowing the service characteristics of the line in detail,and providing new analysis methods and theoretical basis for improving the maintenance and repair level of heavy-duty lines,which is important for ensuring the sustained safe and stable operation of heavy-duty railways.This work focuses on the study of the state of heavy-duty railway lines,and the following research work has been carried out:1.Based on the vehicle-track coupled dynamic theory and finite element theory,a three-dimensional coupled dynamic model of heavy-duty train and track is established,which includes multiple subsystems,including heavy-duty locomotive subsystem,heavy-duty cargo vehicle model,wheel-rail interaction model,track subsystem,hook-buffer system connection subsystem,etc.The multi-body dynamics and finite element software are used to establish the coupled interaction model of heavy-duty train and track,and the modeling process and evaluation criteria are elaborated in detail.2.Using the field testing irregularities as the wheel-rail excitation,based on the established model of heavy-duty train-track coupled dynamics,the influence of factors such as curve radius,curve length,and super-elevation on the dynamic response of heavy-duty trains and tracks is studied,and the influence of changes in related parameters on the performance of heavy-duty train operation is further obtained.This provides a theoretical basis for reasonable curve design and also has a certain reference value for the renovation of existing sections.3.Based on field testing,the influence of rail corrugation on the operation performance of heavy-duty locomotives and freight cars on heavy-duty lines is studied.with the length and depth of wave as reference standards,and the safety control limit value of rail corrugation is analyzed and determined,which provides a theoretical reference for the maintenance and repair of heavy-duty rail tracks.4.Two types of rail defects,rail collapse and crack diseases,which pose a threat to railway transport safety,are studied,and their impact on locomotive,freight car,and track dynamic performance is analyzed.The degree of influence of rail collapse and crack on the safety of train operation and the deterioration of the wheel-rail contact relationship is clarified,and a reliable theoretical basis is provided for the maintenance and repair of rails.