Author : Abhishek G. Chavan

An impact attenuator is a structure used to “Decelerate impacting vehicles gradually to a stop” By gradually decelerating the racecar; the frame and driver are protected from significant deformation and injury. The bulk of impact energy is transferred into the deformation of the impact attenuator structure. Attenuators can be placed on vehicles or on road barriers to absorb large impacts to protect frames and people. FSAE specifies that each car in operation must have an attenuator that meets specifications and testing criteria Impact Attenuator when mounted on the Front Bulkhead, would give an average vehicle deceleration of less than 20g while hitting a non-yielding surface. The data requires the vehicle is traveling at 7 m/s during the impact with a total mass of 300 kg. The peak deceleration during the impact must be under 40g. Material testing of honeycomb, polyethylene foam and polyurethane foam is carried out. In that polyurethane foam is giving better energy absorption. By using polyurethane foam design and fabrication of impact attenuator is carried out. Drop testing result give deceleration of 13.37 g and simulation result on LS-DYNA give deceleration of 15 g. So it is safe to use polyurethane foam as an impact attenuator

Keywords: Impact Attenuator, Polyurethane Foam, Stopping distance, Deceleration, Material Testing, Ls-Dyna, Simulation