Research On Car Frontal Impact Simulation And Crashworthiness Analysis

With the rapid development of our economy, vehicle is becoming more and more popular as a modern means of transportation. On the one hand, the rapid growth of vehicle quantity brings great convenience to people's life and production, but at the same time the casualty rates from traffic accident continue to ascend. So the vehicle's praiseworthiness must be researched at the development stage to improve the performance of vehicle's passive safety and decrease the casualty. At present, the world's major automobile manufacturers have develop a strict collision safety regulation, automotive production and development requirements must pass a stringent standards.The thesis elaborates the development of vehicle collision safety regulation,the research status, contents, methods and development trend of the crash simulation at home and abroad. The thesis detailedly introduces the numeric calculation theory in collision process—explicit dynamic non-linear finite element basic theory. It includes finite element control equation, FE discretion equation,shell elements algorithms, time integration and time step algorithms, hourglass control, contact-impact algorithms etc.In accordance with frontal impact simulation between car and rigid wall, the thesis builds FE models for the whole car and rigid wall, including geometry model simplified reasonably,improving and importing CAD data, cleanuping geometric body model, meshing and checking grid quality, choosing cell types of every part, defining contact types and weld types, simulating rigidwall,setting attribute of nonlinear material, setting initial condition and boundary condition and so on.According to regulations of the C-NCAP and American FMVSS208 for frontal impact, the thesis simulates the impact process for full frontal impact,40% offset frontal impact, car-ploe impact, car-car impact applying nonlinear finite element theory and using HyperMesh, LS-DYNA software. On the base of the results,analyses the deformation, acceleration, energy and section force for body model, summarizes the impact rule in impact process.Through comparison with related literatures, in the thesis the simplification model is fundamental accurate, its result of analysis is also fundamental accurate, conforming to basic regulation of numerical simulation of impact. The work has referential value for impact security simulation research, body structure design, safety performance analysis and traffic accident treatment. At the end of the thesis, achievement and shortage in the thesis is put forward.