Effect of off-centred loading on roll stability of multi-trailer trucks

The effect of partial loading on the wheel tip-up and rollover stability of 28-ft A-double tractor-trailers is studied using TruckSim (R). The model parameters are determined based on measurements and test data, and the model is validated using track data. Four loading conditions are considered: empty, side-loaded, front-loaded, and fully-loaded. The simulation results of a 150-ft J-turn manoeuvre indicate that front- and side-loading of the rear trailer leads to the largest load transfer ratio (LTR) and tip-up, compared with loaded and unloaded conditions. Beyond the trailers' dynamics, unloaded and side-loaded conditions result in lower dolly tip-up speeds, compared with the other load conditions. The side-loaded condition yields the lowest critical rollover speed (CRS). The fully loaded trailer is more prone to rollover than the front-loaded and unloaded cases. The study also suggests that for loaded and partially-loaded cases the static stability factor (SSF) can provide a good first-order estimate of CRS.