A Simulation Study On Car-Highway W-beam Guardrail Impact

In recent years, with the total number of motor vehicles and highway mileage expanse continuously in our country, traffic accidents that happen on the highway are increasing year by year. Among them nearly 1/3 accidents are due to the impact between vehicles and guardrails, and bring a large number of losses to human s life and property. The study on vehicle-guardrail impact is still at the starting stage at present in our country, so the research work that carries on in this aspect has a very realistic and great meaning.From views of vehicle and barrier, car crash with highway barrier was studied systematically in this paper by using computer simulation. Firstly, background of highway development and data collecting and statistics analysis of highway accidents at home and abroad were carried out. Researches of vehicle-barrier crash accidents on highway were compared between in and outside China, and several significant conclusions were acquired. The category, design and guidelines of highway barriers were then described.Based on dynamics simulation software MADYMO, a multi-body car and finite element W-beam guardrail impact model has been established. By studying the dynamic response of vehicle and guardrail in collision, this paper announced the inherent relation between the damage of the persons and relevant factors of traffic accident, such as the impact angle, impact speed and so on.After analyzing the external factors, this paper went on to study the inherent relation between the guardrail s protective performance and its internal factors, such as the guardrail s design parameters m,h₁ and r_i. The results were analyzed from the time history of energy absorbed by the guardrail and acceleration on the car s mass center. From the results we can see, the active barrier can absorb much more impact energy than the other two, and the three corresponding design of the active barrier are optimal. And the active barrier has a lowest acceleration in the X direction, but a highest one in the Y direction, and too little difference in Z direction to be considered, the design parameters m, h₁ and r₁ have come to the similar conclusions.Finally, on the basis of summarizing dynamics of car and protection behavior of guardrail in car-highway barrier crash, many problems solutions confronted in the current research were presented, and the prospect objectives of further work were also given.