Research On Key Technologies Of Multi-Body Dynamic Parameters' Extraction And Model Conversion Of High-Speed Train

The high-speed train is a typical complex mechanical system. Dynamic analysis and simulation is the key of the development of high-speed train. It affects the vehicle running safety and comfort, and also relates to the improvement of speed. Dynamic model's construction is a key technology for dynamic analysis and simulation of high-speed train system. At present, the main methods to construct dynamic model are through dynamic analysis professional software's design template or through the conversion from geometric model with specialized interfaces or intermediate format, then interactively define the multi-body dynamic parameters, kinematic pair information, force information, etc. These manual interactive methods are time-consuming and error-prone. Combining with the project this paper studies the key technologies of conversion between design geometric model and multi-body dynamic model, and develops related function modules in the CATIA system with CAA secondary development to improve the efficiency of constructing the multi-body dynamic model.The first chapter summarizes the key technologies on the research of the conversion between design geometric model and the dynamic model and reviews the research status from domestic and abroad. The key technologies involve to obtain multi-body dynamic parameters from geometric model, to construct abstract simplified model and to reuse assembly constraints information. For high-speed train, it is also related to the suspension system's definition in the dynamic model. The chapter also discusses the existing problems about the technologies, gives topic source and the research content, and describes the arrangement of the contents of this article.The second chapter is put forward a method to obtain multi-body dynamics parameters based on the attribute adjacency graph, in order to achieve the purpose of dynamic parameters quickly. For the parameters attached to the entity, search the higher similar model with template model to gain the parameters. For the parameters attached to the geometric features, look for the geometrical characteristics of the mark, thus through further calculation to get parameters.The third chapter researches the construction of high-speed train simplified model of abstract entity for the dynamic model. According to the structure make the decomposition of high speed train, to simplify each one of the main structure. Combine the simplified model into assembly model, and map the sizes and poses of design geometric model's main components to the simplified assembly model.The fourth chapter presents the reuse method of mechanical products assembly model's constraints information for the dynamics analysis. Through the analysis of assembly information and the corresponding geometric elements with constraint degrees, according to the mapping relationship of kinematic pair and constraint degree and geometrical element, realize the conversion from assembly constraints to kinematic pair information. For the suspension system, to interactive define the markers and the properties of the springs and dampers.The fifth chapter presents the development and realization of the high-speed train digital simulation platform multi-body dynamics interface's related function modules. Using the CAA secondary development technology in CATIA system to obtain multi-body dynamics parameters, the key geometry sizes and simplify the design geometric model, get the assembly constraints information, convert the assembly constraints to kinematic pair information, define the suspension system information. Through the integrated data above information, the dynamic model of rapid reconstruction can be realized, to provide the foundation for subsequent dynamic simulation analysis.The sixth chapter summarizes achievements of this dissertation, and discusses the area which needs to be improved and further research.