Prediction of whole body vibration through a multibody model of a tractor seat

The vibrations transmitted to the driver induce permanent and temporary damage to the body. The agricultural tractors are characterized by a vibration level that can be higher than the exposition level fixed by the 2002/44/EC, in some conditions. The vibrations on tractors have a high intensity and a low frequency with the consequence of difficulties in the project of suspension systems able to reduce the intensity of the level. The numerous innovative suspension systems studied in the recent years, as the active and semi-active seats, did not introduce significant improvements. In the present paper a multibody model of a seat suspension system to an agricultural tractor with a 170 kW power, has been defined with the goal to predict the seat acceleration and evaluate the reduction of the vibration level transmitted to the driver.