Health risk related to whole-body vibration in agricultural tractor: ballast and displacement speed
Mechanical vibration can lead to health problems in workers during the performance of their professional activities. The objective of this study was to evaluate the vibration incident on the whole body of the agricultural tractor operator in a standard track of vibration tests under different ballast conditions and displacement speeds. A 4x2 AFWD agricultural tractor with 92 kW engine power was tested in four ballast conditions: total ballast (70 kN); solid ballast only (54 kN); liquid ballast only (54 kN); and without any ballast (48 kN), at four working speeds: 1.19 m s-1; 1.47 m s-1; 1.75 m s-1 and 2.08 m s-1. The values regarding axle accelerations, the sum of axes for mean accelerations, and the vibration dose value were evaluated by analysis of variance and separation of means (Tukey, p<0.05), in addition to principal components analysis (PCA). Speed was the most influential factor in the vibration generated. The lowest values of mean acceleration and vibration dose value were found in the combination of the lowest speeds with the highest weight of the tractor, while the highest values occurred in the combination of higher speeds with lower weight and liquid ballast. The accelerations obtained on the y axis were more determinant in data behavior than those found in the x and z axes.