Influence of tyres characteristics and travelling speed on ride vibrations of a modern medium powered tractor Part II, Evaluation of the health risk

In this paper, according to ISO 2631/1, 1997, the influence of the mechanical vibrations on human health is evaluated and assessed with four methods: the health guidance caution zones (HGCZ), the estimated vibration dose value (eVDV), the fourth power vibration dose value (VDV), a combination of various methods presented in literature. The normative refers to the HGCZ, which involves the average RMS vibration emission level and its exposure time during a given working day. Values of crest factor for the operator seat showed that Z-axis was the more solicited, even if all the crest factor values are below 9. Results of mechanical vibration in respect of comfort and health, according with the method of the HGCZ, showed that only case B, at higher forward speed, does not exceed the lower boundary of the zone. According to the fourth power vibration dose method and ratios for comparison of basic and additional methods of evaluation, the results showed that only case A, at lower forward speed, does not exceeded 1.25.