Response of human body to tractor vibrations and its minimisation by provision of relaxation suspensions to both wheels and seat at the plane of centre of gravity

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Department of Mechanical Engineering-Engineering Mechanics


In this study, the occupant and the tractor were modelled together in the form of a lumpedmass system interconnected by springs and dashpots and the tractor was provided with relaxation suspensions to the front and rear wheels and seat (at the plane of centre of gravity of the tractor). The response of the composite model to vertical vibrations was found by computer simulation. The parameters of the relaxation suspensions was determined such that the body segment response to vertical vibration were minimised in the 0·5 to 11 Hz frequency range. It was found that the relaxation suspensions provided (with suitable parameter values) reduced the maximum (i) vertical body segment response by 90%, (ii), chassis pitch by 75%, (iii) relative displacement between body parts to a value of 0·7 mm and (iv) accelerations of body parts to levels below the 2·2 h 'exposure limit' tolerance curve, proposed by ISO, thereby considerably improving riding comfort.

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© 1980 IFMBE. Publisher’s version of record: https://doi.org/10.1007/BF02443126

Publication Title

Medical & Biological Engineering & Computing