Static simulation and analyses of mower's ROPS behavior in a finite element model

Area of Science:

• Agricultural Engineering
• Mechanical Engineering
• Biomechanics

Background:

• Rollover protective structures (ROPS) are critical safety devices for agricultural machinery.
• Understanding ROPS performance under lateral impact is essential for operator safety.
• Previous research often lacks detailed numerical prediction and field validation for lateral rolls.

Purpose of the Study:

• To numerically predict the maximum lateral force on a mower ROPS during a continuous lateral roll.
• To determine the energy absorbed by the ROPS during such an event.
• To validate the finite element (FE) model using field measurements.

Main Methods:

• Developed a finite element (FE) model of the ROPS incorporating elastic and plastic deformation theories.
• Validated the FE model using field measurements from a John Deere F925 mower undergoing lateral rolls on a test slope.
• Simulated lateral force application in the FE model to match field-measured maximum deformation.

Main Results:

• The FE analysis indicated that the ROPS top corners experienced slight plastic deformation.
• Maximum predicted lateral forces were 19650 N (on pad) and 22850 N (on soil).
• Energy absorbed by the ROPS met OECD Code 6 static test requirements when tested on soil (1813 J), but not on a pad (643 J).

Conclusions:

• The FE model accurately predicted ROPS behavior during lateral rolls.
• The ROPS of the John Deere F925 mower, even when deformed, did not intrude into the occupant clearance zone.
• The study provides valuable data for ROPS design and safety validation under lateral rollover scenarios.