The Formula SAE design requirements state that the impact attenuator when fixed to a 300kg car (including the driver) which when experiences an impact at a velocity of 7 m/s, must be capable of absorbing the energy without exceeding the maximum deceleration of 40g and average deceleration of 20g and it must be able to withstand an off-axis collision as well as a direct collision. This was achieved by increasing the rate of change of area along the length of the impact attenuator, making the shape of the final design a truncated pyramid. The length and mass of the impact attenuator has been designed to be as small as possible in order to reduce the length of the overall car. This design was validated and has been found to meet all the Formula SAE requirements through the physical testing done by Final Year Student Nurul Mohd. Instead of the dynamic test, a steady state crush test on a full scale impact attenuator was used alongside a compression test at different speeds to predict the behaviour of the material at 7 m/s. This test was used as a method to validate the design of this impact attenuator. The design utilises the chosen material to produce a small lightweight solution. The properties of this material made the design and behaviour prediction of the impact attenuator comparatively simple.

A steady state crush test on full scale impact attenuator

Compression test on cube of foam

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