Model to Evaluate Exposure Criteria During Roll-over Protective Structures (ROPS) Testing

Abstract

The recently approved ASAE Standard S519 includes an exposure criteria which must be satisfied by the tested roll-over protective structure (ROPS). The exposure criteria describes a failure condition in which the clearance zone is exposed to the ground plane during a tractor overturn. A Fortran program was developed to determine if the clearance zone is exposed to the ground surface as the ROPS is deflected during the static test. The model results are compared to actual ROPS static tests to evaluate its accuracy. ROPS two-post and one-post static tests were both executed. Results from the two-post test showed the clearance zone was exposed to the ground plane at a horizontal ROPS load point deflection of 316 mm. The one-post test was more conservative and revealed exposure at 313-mm deflection. The model predicted the exposure of the clearance zone at a ROPS deflection of 340 mm. This model can assist ROPS testing when evaluating the exposure criteria.