International Journal of Scientific and Research Publications, Volume 3, Issue 3, March 2013 1 ISSN 2250-3153 www.ijsrp.org Cost Effective & Innovative Impact Attenuator for Formula SAE Car with Drop Test Analysis Arpit Singhal, Vignesh S. Subramanium Computational Fluid Dynamics, University of Petroleum and Energy Studies, Dehradun Abstract- The impact attenuator [7] is an energy absorbing device installed forward of the front bulkhead of the car with the function to absorb energy and to protect the driver from a sudden change of momentum experienced during an event of a collision. It achieves that by deforming plastically and absorbing a part of the total energy involved during a collision. Aim of this paper is to provide innovation towards the usual and conventional Honeycomb Structured Attenuators for FSAE cars, and testing its effectiveness with drop weight test analysis providing average deceleration impact of vehicle to be less than 20g, which is required according to FSAE design rules. Index Terms- Cost Effective Innovation, Drop weight Test Analysis, Formula SAE, Impact Attenuator I. INTRODUCTION[4] [5] [6] fter researching over the internet it was found that honeycomb structure was mostly preferred for Impact attenuator, usually an Aluminium Honeycomb was used, with some teams using carbon Fibre Honeycomb. With the resources in hand Honeycomb was just out of league, as a result considering the need of an hour to think innovatively it was decided that empty beer cans, 600ml cold drink plastic bottles, and 330ml coca cola cans could make up a potential impact attenuator. Also the FSAE design rules didn‟t mention of how the impact attenuator should be, it just mentioned it to be constrained within certain dimensions and providing experimental data to provide its effectiveness, so the focus was to design the attenuator in a way to comply with FSAE deceleration and size rules with minimum cost and maximum result. II. DESIGN OF IMPACT ATTENUATOR [1] [2] A shell of sheet metal was designed to accommodate the bottles/cans minding the minimum dimensions as required by the rules. The shell was made in the shape of a frustum of a pyramid with the upper cross-section of 240mm * 150mm and the lower cross section of 320mm * 230mm with the height of the shell as 215mm. With these dimensions the shell was designed using SolidWorks. Figure 1: [1] [2] To accommodate the bottles/cans in the shell was the next step; the bottles and cans were fixed to the shell using plaster of Paris. The maximum diameter and the length of the bottles/cans were: ฀ Beer can: Max Dia meter = 60mm and length = 160mm ฀ 600mL Cold drink Bottle: Max Diameter = 69mm and length = 245mm Orientations of bottles/cans were made in such a way that their axes were parallel to the axis of the frame. The length of the beer can is less than 215mm (length of the shell). Oasis foam (easily available from a florist) of thickness 55mm was added to fill the gap, while the length of 600mL Cold drink bottle is more than the length of the shell so the bottle was cut from its end to the length of the 215mm. Using SolidWorks simulation it was found that each shell could accommodate about 6 bottles or cans. Figure 2: [1][2] After the bottles/cans with the shell are assembled, the lower cross section of the shell (320mm * 230mm) was welded along its edges to the center of a base plate (390mm X 290mm). The base plate made of sheet metal was bolted to the anti-intrusion plate [8] A