The Roll Over Protective Structure (ROPS) is a key safety feature in agricultural and forestry tractors in order to minimize risks to the driver in case of rollover during normal use. The Organization for Economic Co-operation and Development (OECD) in an effort to improve operator's safety in Agricultural and Forestry Tractors has set up harmonized testing procedures for ROPS systems. The current OECD Codes for tractors relate to several features of performance. OECD Code 7 is related to the strength of ROPS fitted on narrow-track tractors. On the one hand, Code 7 foresees a sequence of loadings that the protection system has to withstand until the prescribed energy or force is satisfied. In addition to successfully resist the loading sequence, the ROPS has to guarantee a clearance zone during the complete loading sequence. Nowadays tractor manufacturers often adopt numerical simulations for ROPS designing so as to foresee in advance the strength behaviour of the protective structure with respect to the standardized ROPS tests requirements. As a matter of fact, ROPS simulations turned out to be very useful to understand the behaviour of the protection system subjected to complex loading and get valuable insights into performance. A new approach in ROPS test standardization is evaluating the potentiality of virtual tests as a complement of the official actual tests in defined ROPS testing conditions. A numerical simulation with LS-DYNA® were carried out to virtually assess the performance of a ROPS system designed by the BCS manufacturer for a narrow-track tractor. Then the ROPS was officially tested according to the OECD Code 7 loading sequence. A comparison between the results of virtual and actual tests was performed. The main goal of the simulations was to virtually test the tractor according to the Code 7 prior to official test approval and, if necessary, introduce structural changes in order to successfully pass the ROPS strength tests. The use of numerical simulation accompanied by a robust methodology could ensure a high reliability of the virtual prediction with respect to the normalized tests.
Virtual test as a complement tool of the actual ROPS testing on agricultural tractors
Franceschetti Bruno
;Capacci Enrico;Rondelli Valda;
2017
Abstract
The Roll Over Protective Structure (ROPS) is a key safety feature in agricultural and forestry tractors in order to minimize risks to the driver in case of rollover during normal use. The Organization for Economic Co-operation and Development (OECD) in an effort to improve operator's safety in Agricultural and Forestry Tractors has set up harmonized testing procedures for ROPS systems. The current OECD Codes for tractors relate to several features of performance. OECD Code 7 is related to the strength of ROPS fitted on narrow-track tractors. On the one hand, Code 7 foresees a sequence of loadings that the protection system has to withstand until the prescribed energy or force is satisfied. In addition to successfully resist the loading sequence, the ROPS has to guarantee a clearance zone during the complete loading sequence. Nowadays tractor manufacturers often adopt numerical simulations for ROPS designing so as to foresee in advance the strength behaviour of the protective structure with respect to the standardized ROPS tests requirements. As a matter of fact, ROPS simulations turned out to be very useful to understand the behaviour of the protection system subjected to complex loading and get valuable insights into performance. A new approach in ROPS test standardization is evaluating the potentiality of virtual tests as a complement of the official actual tests in defined ROPS testing conditions. A numerical simulation with LS-DYNA® were carried out to virtually assess the performance of a ROPS system designed by the BCS manufacturer for a narrow-track tractor. Then the ROPS was officially tested according to the OECD Code 7 loading sequence. A comparison between the results of virtual and actual tests was performed. The main goal of the simulations was to virtually test the tractor according to the Code 7 prior to official test approval and, if necessary, introduce structural changes in order to successfully pass the ROPS strength tests. The use of numerical simulation accompanied by a robust methodology could ensure a high reliability of the virtual prediction with respect to the normalized tests.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
