Research on Vehicle Lateral Stability Under Flow Impact During Wading

The growing frequency of extreme rainfall events attributable to global climate change has heightened concerns regarding flood-related hazards to road traffic safety. Under wading conditions, vehicles become susceptible to lateral sliding, flotation, or rollover when exposed to lateral hydrodynamic impacts, jeopardizing both occupant safety and infrastructure integrity. Previous studies have largely focused on longitudinal vehicle instability in wading scenarios, including topics such as incipient motion velocity and critical flotation depth, along with hydrodynamic analyses under head-on or tail-on flow conditions. In contrast, limited attention has been given to the dynamic response of vehicles under lateral inflow conditions, particularly concerning the mechanisms of lateral sliding and multi-degree-of-freedom instability modes. To address this gap, a multi-body dynamic model of a vehicle subjected to lateral inflow is developed in this investigation. This model incorporates transverse hydrodynamic forces, tire–road interaction friction, and vehicle attitude variations. The study examines the functional relationship between critical lateral sliding velocity and water depth, evaluates the influence of vehicle attitude on lateral stability, and proposes hydraulic perception-based criteria for critical sliding velocity and attitude angle. Research elucidate the correlation between the vehicle’s sliding velocity and water depth during wading operations. Furthermore, the effects of lateral offset and yaw angle on vehicle performance under lateral impact conditions are quantified. The findings indicate that increased water depth corresponds to a reduction in the critical lateral sliding velocity. Moreover, the most critical condition for lateral instability arises when the flow impinges perpendicularly on the vehicle's side profile. These outcomes contribute theoretical insights and technical foundations for the design and safety assessment of vehicles operating in flood-prone environments, supporting enhanced robustness against hydrodynamic-induced failures.