Studies And Applications Of Some Key Technics In Railway/Maglev Trainset Virtual Prototype

Virtual Prototype (VP) technology is a new design method for all complex products. In this paper, the definition and implied meaning of Virtual Prototype is firstly given, and then, the research situation and future development about Virtual Prototype technology are summarized. According to the technological complexity of rail-wheel/MagLev trainset, which is very typical products in railway vehicle industry, it is proved that shortening the design period and decreasing as large as possible the venture of physical product are total feasible and urgently needed while based on the Virtual Prototype technology.In this paper, it is theoretically addressed that performance simulation is able to create more additive value than CAD technology. As performance simulation is the key technology of Virtual Prototype, so the main research direction in this paper is therefore constructed following it.While using the Virtual Prototype technology, how to keep the high fidelity of performance simulation is key issue, and it has being pointed out how to create good simulation model is the most key issue also. In order to avoid such a wrong incline excessively depending on commercial simulation software, the many-year experiences coming from dealing with the real engineering problems are summarized, and the four principles, which could be used to create the simulation models, are established as well. The four principles are: (1) Energy Equivalent Exchange Principle; (2) Qualitative Mechanics Principle; (3) Keeping Main Contradiction Principle; (4) Feedback Principle. At same time, some useful technology for creating models and how to avoid and find some mistakes in models are suggested as well. Based on these principles and useful technology, three FEA models of newest and most complex products among all railway vehicle factories in China are created. And they are: (1) high-speed train with 210Km/h constructed with hollow-shape aluminum beams; (2) stainless steel city-car constructed with stainless steel and using spot-welding technology; (3) mid-/low-speed EMS MagLev trainset constructed with hollow-shape aluminum beams and composite material named as cellular layers structures. In these three engineering applications, according to the structure feature, the master-slave displacement constrain modeling technology is employed to define the special node which is able to keep two nodes always have same displacements such as spot nodes and rivets. Since the size of each cell is too small to create its finite element model, so keeping its main features, a new special method is employed which is named big-cell method. Comparing the results between the finite element analysis results of virtual prototypes and the measured results of corresponding physical prototypes, it is clear that the above modeling principles and technology are very useful and practical. The more details within comparisons are given in the paper in addition.In the dynamical simulation aspect, in order to obtain more information, rigid-flex hybrid modeling technology is developed. Both arithmetic and interface technologies of rigid-flex hybrid modeling are discussed. Taking the disc-brake paradigm of rail-wheel trainset as an example, the whole rigid-flex hybrid modeling technological flow chart is established.Taking into account that the coupling features of multiple-domain in rail-wheel/MagLev train set, the co-simulation and integration among many different software environments are investigated. Taking buckling-mechanism analysis of solid/liquid coupling in water-tank as an example, it is shown that co-simulation and integration are important technology underperformance simulation environment. Based on PDM technical management mode, collaborative management frame is presented in this paper for managing so many midway data files.Because the active control is another key technology and it could be used to increase the running speed when train is still running on the existing-grade railway, and also because the mid-/low-speed EMS (Electro-Magnetic Suspension) MagLev trainset comes into the city railway transportations, which has the extreme economical and ecological advantages, so at the end of this paper, the research about active control technology is focus on such three difficult problems: (1) output errors caused by the integral step harmonization; (2) the high-frequency error produced when the controller code-model being imported into ADAMS environment; (3) initial velocity non-sensitivity in linearising the dynamical model. After solving such problems, various engineering applications are given to verify these solving strategys. As a trial technical exposition, the three parameters in PID control are optimized through the genetic arithmetic and the control system stability is also improved.On mid-/low-speed EMS MagLev trainset, the single-bogie MagLev vehicle dynamical model is constructed including the electro-magnetic levitation control, and successfully solved the mechanical coupling problem solved through the anti-roll beams finally.In the last chapter, three innovations are given as follows:(1) In the field of creating simulation models of complex products, in order to overcome the difficulties such as how to create the model of the spot welds and rivet-jointed structures, based on the master-slave displacement constrain relationship, node-transferred force modeling technology is employed; in order to overcome the difficulties such as how to avoid large scale of elements, based on the static and dynamic energy equivalent exchange principle, the large-cell modeling is employed. And the comparisons between simulation results and the tested results prove the new technology mentioned above is very useful in engineering applications.(2) In the field of increasing the fidelity of performance simulation, four practical modeling principles are proposed: (1) Energy Equivalent Exchange Principle; (2) Qualitative Mechanics Principle; (3) Keeping Main Contradiction Principle; (4) Feedback Principle. These modeling principles have presented their engineering values.(3) In the field of active control, a strategy named as 'seamless solution' is presented based on model immigration, and three very difficult problems have been solved : (1) output errors caused by the integral step harmonization; (2) the high-frequency error produced when the controller code-model being imported into ADAMS environment; (3) initial velocity non-sensitivity in linearising the dynamical model. The consistence between the dynamical control system simulation and the expected theoretical values shows the effectivity of model immigration.