Rollover protective structures (ROPS) that absorb energy during vehicle rollovers
play a crucial role in providing integrated passive safety for operators
restrained by seat belts. These protective structures, integrated into the
vehicle frame, are designed to absorb high-impact energy and deform in a
controlled manner without intruding into the occupant’s safe zone. This research
focuses on the detailed analytical design procedure and performance evaluation
criteria of the two-post open ROPS used on motor graders against lateral loads.
An experimental test on a standard tubular square hollow section (SHS) column
subjected to lateral load has demonstrated a significant correlation between the
post-yield behavior of plastic hinge development and energy absorption, compared
with results from various formulations adopted in finite element analysis (FEA).
To reduce design iteration time and the cost of physical destructive testing,
the complete equipment experimental setup is virtually simulated, building upon
a thorough understanding of plastic hinge formation on columns under large
deflections. This simulation provides comprehensive insights into the structural
elasto-plastic response and employs the nonlinear implicit and explicit schemes
of FEA to accurately predict energy absorption and force vs deflection behavior.
The study follows the guidance outlined in ISO 3471: 2008 standard
specifications, validating key structural performance parameters through virtual
CAE simulation to ensure alignment with the standard’s force and energy
requirements.
The research emphasizes the control of merging empirical and analytical methods
with advanced CAE tools, allowing engineers to design and evaluate ROPS with
superior energy absorption and minimal deflection. By adopting this holistic
approach, designers can significantly enhance ROPS structural integrity,
ensuring improved safety and protection for operators in the demanding
conditions of off-highway vehicles.
