Hgv collisions with steel road safety barriers: combined influence of position of center of mass and tire pavement friction

Abstract Vehicles colliding with highway safety features do not always produce the same effects. Each impacting vehicle will have a different outcome, depending greatly not only on its mass, velocity and impact angle, but also on the position of its center of mass and on the tire-pavement friction. This study analyzes in what way barrier and impacting vehicle behavior is affected by changes in the position of the center of mass and in the tire-pavement side friction, in order to identify the most dangerous loading systems. Towards this aim numerous simulations of a collision of a truck against a steel road safety barrier were carried out through non-linear dynamic finite element analysis. The results obtained demonstrate that the position of the center of mass is of greater consequence in collisions where impact energy is close to maximum barrier containment capacity and in friction-favoring conditions. The center of mass longitudinal position has a large impact on the risk of the vehicle passing over the barrier or rolling over. If it is in the back, the most common loading system, the risk of passing over the barrier is rather limited compared to rollover risk. As the position of the center of mass is pushed forward, on one hand rollover risk is reduced but, on the other hand, the risk of passing over the barrier increases. If the height of the center of mass increases, rollover risk is higher, but without significantly influencing displacement and the risk of passing over the barrier.