Characterisation of mechanical energy absorbers developed to complement of roll-over protection structures in agricultural vehicles

Roll-over protection structures (ROPS) and the use of safety belt is a successful combination in agricultural vehicles. If during an accident, a vehicle overturns, a ROPS is designed to deform plastically, absorbing potential energy of the vehicle, while not infringing the safety volume around the driver. The addition of mechanical energy absorbers (MEA) to a ROPS might enhance this behaviour, improving the safety provided. A disc-shaped mechanical energy absorber, designed for this purpose, is analysed and some geometrical and manufacturing features that influence their behaviour are described. Tensile tests of 6 different variants of this absorber have been carried out. The obtained loadedisplacement curves have been linearized to facilitate the calculation of quantitative parameters that can be used to characterise and compare the behaviour of the tested elements. The relation between some geometrical and manufacturing features of the absorbers and the calculated parameters is discussed. The results show that the proposed mechanical energy absorbers present enough geometrical and manufacturing adjustable variables to cover a wide range of applications.