Research Of Pedestrian Head Injury In Traffic Accident And Pedestrian Protection Equipment

The production and sale of vehicles has increased year by year since the last decade, and the holdings of vehicles have reached a big number. In one word, the prosperity of automobile industry contributes much for social economy, and also people's work and life; in another word, it also causes traffic jam, what's more, it may lead to many more traffic accidents. Pedestrian are more easily injured, so we must pay more attention to protect them. The injuries of head are very serious, since most of deaths are caused by them.This study bases on the structure of head and common head injuries. After studying the investigation and research on pedestrian protection, Multi-body Dynamics, this paper builds a pedestrian model based on Chinese national standard standing for the average adult male. This paper also builds a model of middle-class car and a small car for car-pedestrian accident. PMHS (Post Mortem Human Subjects) testing result, a test of real vehicle-standing pedestrian dummy impact, a simulation result of MADYMO (Mathematical Dynamic Model) are used to validate that the car-pedestrian impact model is correct.After ensuring that the built model is valid, this paper uses this model to calculate the effect of the height of bumper, the stiffness of bumper, the length of bumper, the height of engine hood, the angle of engine hood, the stiffness of engine hood, vehicle windshield stiffness, vehicle windshield stiffness on the acceleration of pedestrian head. From the simulation result, we can get a conclusion that car frontal structure has a great influence on pedestrian head injury. The simulation result shows that increasing bumper height, decreasing bumper stiffness and length, increasing engine hood height and angle, decreasing engine hood stiffness, decreasing vehicle windshield angle and stiffness can contribute to decrease the acceleration of pedestrian head, so that they can ease pedestrian head injury.This paper also introduces a new kind of engine hood deployment device. This device involves a spring-damp system when another has no spring-damp system. The simulation result shows that both of them can ease pedestrian head injury. The system with spring-damp system can make pedestrian head acceleration smaller than the one without the spring-damp system. When sensor detects that the crash between the vehicle and pedestrian can't be avoided, the spring-damp system will begin to work. The spring can ease the crash between pedestrian head and engine hood. The damping system can consume kinetic energy of pedestrian head and engine hood, so that it can make the acceleration of pedestrian head much smaller. The simulation result proves that this system can definitely release pedestrian head injury.