Christian Preti

Three-axial evaluation of whole-body vibration in agricultural telehandlers: The effects of an active cab-suspension system

ABSTRACT Agricultural and earth-moving machinery operators are particularly exposed to whole-body vibration (WBV), which has severe effects on health and affects comfort and performance. Few studies have investigated vibrational safety and comfort issues in telescopic handlers. These vehicles are widespread in many off-road applications—such as construction, agriculture, and mining—used to handle loads and to lift persons and equipment. This study investigated the effects of an active hydro-pneumatic cab-suspension system fitted to a telehandler on a drivers vibration exposure along the x-, y-, and z-axes, through both objective and subjective assessments. Sixteen healthy professional telehandler drivers took part in the study. Objective measurements were acquired at the operators seat, and subjective ratings were taken while participants drove the telehandler with either a deactivated or activated suspension system at 12 kph on an ISO 5008 smooth track. The results showed that the activation of the cab-suspension system reduced the root-mean-square acceleration along the x- and z-axes (p =.038 and p =.000, respectively). Moreover, the frequency analysis showed a reduction in the acceleration along the z-axis in the range of 2–25 Hz (p <.05 for all comparisons); in particular, the acceleration was reduced by 50% in the higher frequency range (4–20 Hz). A reduction in the vibration intensity was perceived by the participants along the y- and z-axes (p =.009 and p =.003, respectively). Implications for the future development of suspension systems are discussed.

Noise emissions in wood chipping yards: Options compared

Industrial comminution is becoming increasingly popular, as the result of a growing demand for wood biomass. Such task is performed with either chippers or grinders, which are large, powerful machines, capable of generating much noise. In turn, high noise levels may have negative impacts on the health and comfort of workers, and of the people living in the surroundings of a wood fuel yard. This study gauged the difference between the two main technology options (i.e. chippers and grinders) in order to offer additional decision elements to wood yard planners. The chipper on test generated more noise than the grinder, due to its better ability to process wood and to transmit more energy into it. Since the chipper was equipped with less working tools and turned slower than the grinder, it generated its noise peaks at lower frequency bands. The grinder on test was more suitable for use in wood yards located near settled areas, and was an obvious choice whenever dealing with a diversified and occasionally contaminated raw material stream.

Hand-held olive beaters: Analysis of the upper limb disorders and hand-arm vibration risks

Hand-held Olive Beaters: Analysis of the Upper Limb Disorders and Hand-arm Vibration Risks Angela Calvo, Elio Romano, Giampaolo Schillaci, Christian Preti, Roberto Deboli a DISAFA (Department of Agricultural, Forest and Food Sciences and Technologies), Largo P.Braccini 2, 10095 Grugliasco, Turin, Italy b CREA-ING. Unità di Ricerca per l’Ingegneria Agraria, Via Milano 43, 24047 Treviglio, Bergamo, Italy] c Di3A (Dipartimento di Agricoltura, Alimentazione e Ambiente Sezione Meccanica e Meccanizzazione) Università degli Studi di Catania, Via Santa Sofia 100, 95123 Catania. d IMAMOTER Institute for Agricultural and Earth-moving Machines of C.N.R (Italian National Research Council), Strada delle Cacce 73, 10135 Turin, Italy giampaolo.schillaci@unict.it