| In recent years, coach rollover accidents occur frequently, people pay more attention to coach rollover crash safety and body structure strength, in order to regulate the depth study of coach rollover theory, home and abroad have issued various safety regulations about the coach structure and test, the ECE R66regulations and FMVSS regulations get approval to all over the world. Our country also introduced GB/T17578-1998based on ECE R66regulations, and argument the structure of the coach strictly in accordance with the security laws and regulations.The paper to a certain type of coach as the research object, according to the requirements of the ECE R66regulations, using Hypermesh to modeling finite element of coach, using explicit dynamic analysis software LS-DYNA to simulate and calculate the process of rollover crash.According to the analysis of the simulation results, we could put forward a series of structure improvement measures, and each measures were simulated. At the same time, we verify the rationality of the improvement measures and improve the coach skeleton structure, and simulate the model again, verify that the above measures can meet the coach rollover crash safety requirements by compare both results. This paper mainly including such work as follows:(1) Refer to the material of rollover. Through the analysis of a large number of domestic traffic accident characteristics, we could propose the necessity and urgency of coach rollover study, and introduce the contents and methods about the coach rollover at the same time.(2) Introduce the simulation theory of coach rollover. The coach rollover involves a large number of test requirements, we will give a detailed introduction on deformation process、control equation and the mechanics model、unit integral and hourglass control、 time integral and step length control and so on.(3) Modeling and rollover crash simulation analysis. Modeling coach frame、platform and living space strictly in accordance with the finite element method; Calculating the coach center of gravity position and theoretical rollover angle; Setting contact-form in the process of crash、load and constraint、time-step and the hourglass、crash acceleration and a series of parameters; Analysis the body deformation、energy transformation、acceleration curve and living space, etc after the simulation. (4) Compare and improve. Verify the rationality of the improvement measures, modify the coach frame structure model appropriately and analysis the simulation comparatively again in order to meet the coach rollover structure safety requirements. |
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