An improved mathematical model for vehicle crashagainst highway guardrails

Abstract

Highway guardrail is a kind of important road traffic safety facility. When a vehicle is travelling on a highway, it can lose control because of accident. The guardrail can prevent the vehicle from rushing directly out of the road, so as to reduce the injury to the driver in the vehicle. Therefore, the guiding performance, anti-collision performance and buffer performance of the guardrail are important indexes to reflect the highway guardrail safety in the traffic accidents between vehicle and guardrail. The process of collisions between vehicles and guardrails is a complex motion, affected by multiple factors such as the movement patterns and types of vehicles, the types of guardrail, the bending stiffness of the beams, the speed of collision, the angle of collision, etc. The accuracy of energy estimation when vehicle collides with guardrail is the foundation of highway guardrail design, installation and improvement. Many experts and scholars at home and abroad have done a lot of theoretical research and experimental verifications on the safety performance of highway guardrail, and analyzed the anti-collision ability and energy absorption effect of highway guardrail. Single degree of freedom model is the most widely used mathematical model of vehicle collision in highway guardrail. The traditional model is more suitable for calculating the maximum impact force of small vehicles, but it is not accurate for large vehicles. However, due to the unreasonableness of the model in the theoretical derivation process, there is a large error in the mathematical model, especially in estimating the accuracy of the energy value of the large vehicle collision guardrail. Practice shows that the current guardrail cannot withstand the impact of large vehicles. Once large vehicles collide with the corrugated beam guardrail, the guardrail will collapse in most cases, and the vehicle will rush out of the road directly, so it is very difficult to exert the protective function of the guardrail. The anti-collision performance of guardrail is poor, which is related to the existing calculation model, which results in insufficient strength in the design of guardrail.

Keywords

• roadway engineering
• mechanical model
• roadway guardrail
• lateral rotation
• vehicle crash