Analysis of the behaviour of biker protection devices for roadside barriers

Existing roadside barriers generally pose a risk for motorcyclist impacts against them; therefore several devices exist and are intended to mitigate the effects of such impacts. The purpose of the study is to investigate the influence of some impact parameters on device behaviour. A numerical crash scenario, according to UNE135900:2008, was built and the effects of three different biker protection devices were simulated. Numerical models were set up and validated against real test data. A simulation campaign was performed investigating the influence of approach angle and speed. Results showed that injury indexes registered by the dummy during the impact rise as approach angle or speed rises. A regression analysis was carried out and the relationship between impact severity, represented by injury indexes, and both the investigated impact parameters proved to be quadratic. An explicative theory is proposed, pointing at that part of kinetic energy that is associated with the component of approach speed orthogonal to the barrier as the most influent parameter on the device performance.