Evaluation of solid attachment effects on static stability and operator head injury criterion (HIC) in agricultural all-terrain vehicles (ATVs) using finite element modeling (FEM)

All-terrain vehicles (ATVs) are widely used in agricultural operations, yet rollover incidents remain a major cause of severe injury and fatality among farm workers. The addition of attachments alters the vehicle’s center of gravity (CG) and may significantly affect stability and injury risk. This study developed and validated a multi-body finite element (FE) model of an ATV equipped with front and rear rack attachments, a tandem-axle trailer, and a 50th-percentile rider dummy to evaluate static rollover stability under varying operational conditions, enabling the assessment of configurations such as ATV-trailer systems that are costly and difficult to test experimentally. The model incorporated CG measurements obtained from tilt-table and corner-weight testing. Static stability was quantified using the tilt table ratio (TTR) under forward pitch, rearward pitch, and lateral roll conditions. Head injury risk was assessed using the 15 ms head injury criterion (HIC 15 ) during simulated rollover events. The FE model predictions of TTR showed good agreement with experimental results (average percentage error generally < 10 %). Attachment configuration significantly affected stability across all rollover modes, with rear and combined rack loads producing the largest reductions in TTR. Lower tire inflation pressure reduced forward pitch stability and interacted with attachment configuration in lateral and rearward rollovers. Forward pitch rollovers generally produced the highest HIC 15 values, reaching 1095 for the ATV equipped with both front and rear racks. The relative severity of rearward pitch and lateral rollovers varied with attachment configuration. Nevertheless, nearly all predicted HIC 15 values remained below the accepted injury threshold of 700.