Crash Simulation Of Vehicle-guardrails And Optimization Of The Rail Post

With the development of economy,cars have become an important tool for people to travel.The popularity of cars has brought great convenience to people,but on the other hand,it has also caused more and more traffic accidents.The guardrail is an important part of the traffic safety facilities.It can effectively protect people,s lives.Therefore,it is necessary to study the crashworthiness of guardrail.Computer simulation plays a very important role in solving the collision safety problem of vehicles and guardrails on highway.The object of this paper is to simulate the crash between car and guardrail,so take a car as an example,the finite element model of the guardrail is established according to the requirements of the details in the design of road traffic safety facilities,and the finite element model of the collision safety system of vehicle guardrail is established according to the evaluation specification for highway safety barrier.Secondly,the finite element simulation analysis is carried out on the collision system and the existing guardrails are analyzed in the running track of the vehicle,the acceleration of the vehicle center of mass,the maximum deformation of the guardrail and the energy absorption of the various parts of the guardrail.It is found that snagging effect of the rail post to vehicles in the process makes the acceleration of the center mass exceed the national limit 20 g,which makes the safety of the occupants in the vehicle seriously threatened.In view of the theoretical analysis of this phenomenon,the causes of the snagging effect are found out,and two methods of improving the rail post are proposed,which are the N-shape rail post and the foam rail post.Then,two new rail posts are proved to have obvious effect on improving the safety performance in the collision between cars and guardrails through simulation.At last,the influence of the thickness of the W-beam rail panel,the spacing of the post,the thickness of the post and the structure of the post on the collision system between the car and the guardrail was studied by the orthogonal test.The better combination of parameters is selected and it is verified that the combination can effectively avoid or reduce the snagging problem.Compared with the original guardrail,the crash safety performance of the combination has been greatly improved.