An Optimization Of Vehicle Frontal Structure Design For Pedestrian

From the 60 decade of the last century, some developed countries have started to pay attention to pedestrian hazards, and begin a pedestrian protecting safety research. Due to the complex road traffic condition in our country, pedestrian injuries are more frequently. "people's Republic of China road traffic accident statistics annual report ( 2007)" shows 21000 people dead because of traffic accident , 25.85% of total traffic deaths which comes out top in the world. IHRA research shows, head injury takes 31.4% account of human injury in total area. Along with the constant attention to pedestrian safety, the GB / T24550-2009 car pedestrian collision protection of national standards has been implemented in July 1, 2010. Then some automakers also began to conduct the head crash test research. In order to relieve road traffic accident injury to the pedestrian head impact, these researches are particularly important.Based on key issues and research methods about the pedestrian protection in the world, pedestrian protection regulations and comprehensive evaluation rules as well as the analysis, according to the C-NCAP pedestrian protection evaluation rules requirements, on the basis of the children's head crash test, finite element analysis model is established. And then the structure is improved and analyzed, the experiment is also verified. The results show that the improved vehicle front structure can effectively reduce head injury value.Combined with the design examples, this paper introduces the method of model establishment and pedestrian protection finite element mesh generation, boundary condition processing principles, and establishes the pedestrian protection analysis model. Then mark the collision region on the outer CAS of models to determine the head impact area. And next, static analysis for modeling is made in the children head impact area and adult head impact area. Then pedestrian protection design principles are proposed. Based on the analysis of the layout in the engine room, risk areas on the radiator upper support and batteries are found.This article makes crash finite element analysis on the engine cover system for child head on the different regional point of impact head injury values and crushing space. Then obtain hood stiffness distribution trend to provide a reference for further analysis. On this basis, the child head crash finite element analysis can be made on the vehicle to assess the C-NCAP pedestrian head impact scoring in the dangerous area and have the improvement direction.Finally, through the above analysis, the engine hood lock fixing board structure is optimized and the deformable bracket is used on the radiator beam. The finite element analysis shows that a part of collision energy is absorbed and the head HIC is fall down by using the optimized structure. Three collision tests in different points verify the rationality of optimization scheme and the validity of finite element analysis model. Finally the optimal scheme of head crashes meets the requirements of pedestrian protection in C-NCAP.