Whole body vibration in operators using agricultural soil preparation equipment
ABSTRACT: Agricultural tractors have been reported to exert negative effects on operator health. It is well known that when a farm machine is designed it must consider the human factors, to raise the safety levels and work quality. The aim of the present study was to estimate the degree of vibration transmissibility from the agricultural equipment used for the periodic soil preparation process and determine the exposure of the whole body of the operator to the vibration, incident to the agricultural tractor during the operation. A 4x2 TDA tractor was employed, coupled to the periodic soil preparation equipment. Five sets were used (tractor- disk plough, tractor-moldboard plow, tractor-offset disc harrow, tractor-rotary hoe, and tractor-scarifier) and the tractor without the equipment being coupled, at two tractor speeds of displacement (3.5 km.h-1 and 6.1 km.h-1). An index (IAVEA) was developed to assess whether the amplification or attenuation of the vibrations takes place on each orthogonal axis. The data were processed using the Noise Studio® software 6.95. Statistical evaluation was performed using the ASSISTAT version 7.7 beta program. After normality, the data were submitted to the analysis of variance by the F test; when significance was reported, the means were compared using the Tukey test, at 5% significance. The disk plow was the equipment that showed the greatest intensification of the vibrations in all the parameters estimated. All the sets assessed revealed statistically equal or higher values in terms of the tractor without the attached equipment. The IAVEA% was an index that enabled the quantification of the amplification or attenuation caused by the use of the agricultural equipment.