Analysis of Crash Barriers in Terms of Impact Strength

Abstract

Run-off road vehicle crashes are a major cause of loss and causality on roads, with errant vehicle incidents often leading to potentially serious injury or death for both the vehicle user and other road users. A road safety barrier is designed to safely control and redirect errant vehicles, absorbing the energy from the collision event and minimizing injury to vehicle occupants or other road users. This study aimed to show the impact performance of semi-rigid and flexible crash barriers in terms of energy absorption of barrier, ASI value and deflection. Finite Element Software Abaqus was used to develop models of three types of barriers, i.e. w-beam steel crash barrier, modified thrie beam steel crash barrier and cable barrier. The barriers were impacted upon by simplified vehicle model with an impact velocity at an impact angle to carry out the computer simulation using Abaqus. Crash simulation were carried out under different conditions of impact varying the impact velocity as 80 kmph, 60 kmph, 40 kmph and 30 kmph and impact angle as 15º, 20º and 25º. The impactor of 2000 kg and 8000 kg were used. The simulation results of the models showed that the optimal result was registered by the cable barrier, which demonstrated higher crash energy absorption and a lower ASI value than the other barriers did. Overall, it was found that both the barriers, modified thrie beam and cable barrier could be preferred for use over w-beam barrier, also considering the lateral space availability at installation site. The space required for deflection was found to be 1.28 m, 0.83 m and 2.35 m for w-beam, modified thrie beam and cable barrier respectively. The modified thrie beam and cable barrier would be more effective for restraining heavy vehicles as found from the results and their use along the hazardous locations would result in more energy absorption of the crash and less risk of injury to the vehicle occupants lowering the severity of crash and eventually improving the road safety aspect.