A rollover protective structure (ROPS) is a highly effective engineering safety control that can avoid or reduce the severity of injuries in the events of tractor overturns. Strength ROPS procedures were introduced in Europe in the 1950s. These tests require a level of energy based on the tractor reference mass and foresee to protect the driver’s clearance zone. The Code 6 of the Organisation for Economic Co-operation and Development (OECD) is a consensus performance standard established for agricultural front ROPS fitted on narrow-track tractors. These tractors ROPS requires more attention because the clearance zone is reduced to preserve the normal operation in orchard and vineyard. Code 6 foresees dynamic and static procedures for the ROPS tests. Dynamic procedure is based on a 2000 kg mass oscillating and impacting the ROPS, instead static procedure foresees a slow rate of load application until the energy level is satisfied. In the current study, according to the OECD Code 6, laboratory dynamic and static tests were carried out on a foldable ROPS fitted in a modern tractor. The work was focused on the evaluation of the ROPS behaviour when stressed dynamically and statically. Dynamic test was carried out on the tractor complete of wheels and attached to the ground, so that the impact energy was absorbed mainly by ROPS and tyres. Otherwise, static test was carried out on the ROPS fitted on the tractor chassis without the contribution of tyres; the tractor axels were fixed on the ground and the whole energy was absorbed by the ROPS. Tests results indicate that the deflection obtained with the dynamic testing procedure is higher than that of the static one. The results seems to suggest that the dynamic testing procedure is more conservative than the static testing procedure. In fact during the dynamic test, ROPS showed a greater deflection and the clearance zone was not preserved. These results could be explained considering that a modern ROPS is designed according to the requirements of the static procedure. However the results suggest the need to extend the comparison between dynamic and static procedures to other types of modern ROPS to verify if differences continue to be observed because this can have effect on the level of safety of the tractor driver.
Bruno Franceschetti, Valda Rondelli, Adriano Guarnieri, Enrico Capacci (2014). DYNAMIC AND STATIC ROPS TESTS ON MODERN TRACTORS. The European Society of Agricultural Engineers (EurAgEng).
DYNAMIC AND STATIC ROPS TESTS ON MODERN TRACTORS
FRANCESCHETTI, BRUNO;RONDELLI, VALDA;GUARNIERI, ADRIANO;CAPACCI, ENRICO
2014
Abstract
A rollover protective structure (ROPS) is a highly effective engineering safety control that can avoid or reduce the severity of injuries in the events of tractor overturns. Strength ROPS procedures were introduced in Europe in the 1950s. These tests require a level of energy based on the tractor reference mass and foresee to protect the driver’s clearance zone. The Code 6 of the Organisation for Economic Co-operation and Development (OECD) is a consensus performance standard established for agricultural front ROPS fitted on narrow-track tractors. These tractors ROPS requires more attention because the clearance zone is reduced to preserve the normal operation in orchard and vineyard. Code 6 foresees dynamic and static procedures for the ROPS tests. Dynamic procedure is based on a 2000 kg mass oscillating and impacting the ROPS, instead static procedure foresees a slow rate of load application until the energy level is satisfied. In the current study, according to the OECD Code 6, laboratory dynamic and static tests were carried out on a foldable ROPS fitted in a modern tractor. The work was focused on the evaluation of the ROPS behaviour when stressed dynamically and statically. Dynamic test was carried out on the tractor complete of wheels and attached to the ground, so that the impact energy was absorbed mainly by ROPS and tyres. Otherwise, static test was carried out on the ROPS fitted on the tractor chassis without the contribution of tyres; the tractor axels were fixed on the ground and the whole energy was absorbed by the ROPS. Tests results indicate that the deflection obtained with the dynamic testing procedure is higher than that of the static one. The results seems to suggest that the dynamic testing procedure is more conservative than the static testing procedure. In fact during the dynamic test, ROPS showed a greater deflection and the clearance zone was not preserved. These results could be explained considering that a modern ROPS is designed according to the requirements of the static procedure. However the results suggest the need to extend the comparison between dynamic and static procedures to other types of modern ROPS to verify if differences continue to be observed because this can have effect on the level of safety of the tractor driver.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
