Computer Simulation And Experimental Study On The Lateral Crashworthiness Of Passenger Car

The eleventh five-year plans of China auto industry has now promoted that"safety, environmental protection, energy saving"will be the most important three aspects in the future of China's auto industry developing, safety has been a"green barrier"for exporting the Chinese brand vehicles to Western market. The United State, European Union and Japan have implemented long-term plan for"Zero Fatalities", their level of vehicle's safety is higher than china. The automobile industry generally divides vehicle safety systems into two types– active safety and passive safety. Active safety describes any technology applied to avoid accidents and minimize the danger in driving by automatic electronic control devices that let the driver is in almost complete control of the vehicle. Passive safety features help occupants and pedestrian stay alive and reduce injury in the event of an accident by vehicle's structural integrity and restrain systems. The frontal crash study of vehicle has been a sophisticate level, comparing with the lateral crashworthiness. The national automobile safety standard--"Vehicle Passenger Side Impact protection"was officially promulgated on July 1, 2006 in China. The new standard, compulsory for all new M1 class vehicles, stipulates that existing car models in production must be modified in accordance with the new national standard within 36 months. China's new national standard promoted higher passenger safety levels for new passenger car developing in the country. Large numbers of domestic universities and automobile manufacturers have invested more money to focus on automobile research to side impact collisions, which was in the first step only.This paper has focused our research on the safety of side impact collisions by developing an entirely new car body project, including lateral crashworthiness, fast fine simulation, high strength steel (HSS) correlates directly with the car body crashworthiness. It carries out an all-new proprietary designing process control that covers all period from conceptual design, structural design to real car test. The new B class car was widely known by his safety after launched to the market, customers call it"city tank". The main content and innovation are as follows: First, it introduces the applications about the Finite Element Method and Multi-body Dynamic Systems and integrates them together in car lateral crashworthiness analysis., which includes nonlinear dynamic finite element method, finite element discretization of the collision space, the selection and algorithm of shell element in collision model, time-step algorithm, contact-collision algorithm, the choice of material model , multi-dynamic principle.Second, it builds a system to control the whole process of car lateral crashworthiness from conceptual design, computer simulation to real car test. According as the numbers of analysis, definitions and optimized parameters, it is the first time to build the Multi-body model in side impact, fill in the blank of pre-structural design and settle a basis of in the further car lateral crashworthiness research.Third, it builds a completed model of car crash test, applying HYPER-WORKS, VPG and LS-DYNA to simulate more than 500 thousands units by IBM workstation with 32 CPU. The efficiency is the highest in China.Through calculation, we gain the graph of deformation and stress with time variation, final deformation shape of car, energy curve varied with time, the invasive value of different part, all of which provide great reference to the structure design of car. Forth, it is the first time research on the positive effects of HSS in lateral crashworthiness integrated the metallographic field, design of car structure and computer simulation as whole. It analyzes the influence of high-strength steel distribution, different structure parameters and high-strength steel of different grade on the deformation and energy absorption characteristics. The integration of structure and process is achieved. The anti-collision performance is raised meanwhile the lightweighting begins to come true.Fifth, it is the first time to apply deformation theory to the car side impact analysis, improves the precision of computer simulation about car body structural character analysis by punching stretch of car side body and reflecting the results directly into simulating model of car crash which had established before. Sixth, According the ECE regulations, the computer simulation results mirrored closely those actual tests. It achieves a closed-loop control through different period, such as conceptual design, computer simulation, and experiment validation. It lowers the risk of development and increases the efficiency of research.The paper effectively addresses the car lateral crashworthiness from simulation analysis, process control and experimental validation, and creates a standard process from it. It is significance to the independent-develop of car safety research. And meanwhile it can support national car exporting to the oversea. All the academic analysis including conceptual design, simulation analysis, and effect of HSS etc. involved in this paper is accordant well with the results of those of actual tests. It will move the research of car lateral crashworthiness forward in FAW.