Simulation Study for Overturning and Rollover Characteristics of a Tractor with an Implement on a Hard Surface

The effects of the slope of the ground and the obstacle conditions on the lateral overturning/backward rollover of a tractor with an implement were analyzed through dynamic simulation. The tractor and implement’s 3D simulation model was constructed. As for simulation conditions, four heights and three shapes were set for obstacles, and eight slopes were set for the ground to be traveled by the implemented tractor. Under each condition, the critical speed at which the tractor begins to overturn and roll over was derived, and factors that caused the overturn and rollover were analyzed. As a result of instability types, backward rollover happens when the ground slope is low and lateral overturning happens at a specific slope or higher regardless of the obstacle conditions. In the case of the tractor and implement under study, the tendency changed at a slope of 25°. As the obstacle height increased, overturning and rollover safety decreased. In the case of the obstacle shape, safety was lowest for the rectangular obstacle and highest for the right-side triangular obstacle. The driving safety of the tractor with the implement was lower than that of the tractor with no implement. This appears to be mainly due to the change in the position of the center of gravity caused by the attached implement. The critical speed of the tractor with the implement was 3.26 times lower than that of the tractor with no implement on average. It is judged that the safety of the implemented tractor can be identified by using this study.