Abstract: According to develop a new flexible guardrail terminal which can meet the new regulations in our country, topology optimization of the end head of a novel flexible guard rail under the condition of bus collision was analyzed by adopting the method that combines the analysis of model simulation of the finite element of the car-barrier,full scale crash test of real vehicle with topology optimization of cellular automaton, which was based on the new evaluation criteria both at home and abroad. Under five different condition,topology optimization of flexible guard rail end head design area was analyzed. Moreover, a new topological configuration of flexible guard rail was obtained. Finally, the simulation software was used to simulate and verify the topology of the end head of the four corner arc. The analysis results indicated that:the end head topology of 0.3 mass fraction was able to avoid the occurrence the trip of car body, too high acceleration and rollover accident which was caused by the too high strength of the end head of the flexible guard rail. The maximum acceleration of the car body X, Y, Z axis were respectively 11.0, 0.38, 4.0g, which were all less than evaluation standard acceleration-20g. It meets the safety requirements of the collision. Therefore, it can ensure the normal protection ability of highway guard rails because it can provide enough binding force for highway fences.

Key words: the new flexible structure guardrail ends, cellular automaton, the verification analysis, vehicle engineering, crash worthiness, topology optimization