Computational and Experimental Analysis of Head Injury Criteria (HIC) in Frontal Collision of Car with Pedestrian

Road accident between pedestrian and motor vehicle causes severe injuries and even death of pedestrian. The accident statistics show that the possibility of injury to pedestrian is higher in case of collision with car on busy roads. In car and pedestrian collisions, the pedestrian’s head hits with car bonnet and suffer from multiple injuries such as skull fractures and brain injury. The role of car bonnet structural strength plays an important role in pedestrian head injury level. To provide enough structural strength the high bonnet thickness is provided with under bonnet stiffeners, however thick bonnet and stiffeners reduces deformation of the bonnet during collision and increases injury level to pedestrian. Hence optimum bonnet thickness, least number and geometry of stiffeners and enough structural strength is important for bonnet to reduce injury level. The aim of this study is to analyse the effect of car bonnet thickness, number and arrangement of under bonnet stiffeners on head injury levels with the help of head injury criteria (HIC). Head Injury Criteria (HIC) is a measure of the likelihood of head injury arising from an impact during a car crash. It indicatesthe level of injury caused during a particular crash. A typical modern car bonnet is selected for investigation with variety of bonnet material thickness and different configurations of under bonnet stiffeners and head injury criteria (HIC) is computed with the help of computer modelling. Further, head linear velocity, acceleration and head injury risk are predicted for probability of skull fracture. The geometry of bonnet is optimized with the help of optimization technique and optimized bonnet geometry is validated experimentally by designing a bonnet test facility and head form imparter.