ANALYSIS OF THE INFLUENCE OF LOAD ON THE TURNING PERFORMANCE OF SMALL TRUCKS CONSIDERING TIRE ELASTIC PROPERTIES USING NUMERICAL SIMULATION METHOD

The maneuverability and safety of small trucks operating under the specific traffic conditions in Vietnam heavily rely on their turning performance. This research aims to develop and apply a singletrack planar dynamic model to quantitatively investigate the influence of cargo load (Q) on the turning characteristics of a small truck. The research methodology includes: (1) Developing and establishing a system of differential equations for motion that incorporates the tire’s elastic properties through loaddependent cornering stiffness coefficients (k1, k2); (2) Using the Runge-Kutta 4 numerical method and the Matlab-Simulink software to solve the system of equations. Four load scenarios (Q=0, 1000, 1500, 2000 kg) were surveyed at a velocity V=20 km/h and a maximum steering angle βmax=27.5o. The simulation results show that as the load increases from 0 kg to 2000 kg: the front axle slip angle δ1) significantly increases from 4.80 to 14.50, while the steady-state turning radius (Rcon) only slightly decreases from 6.7759 m to 6.25 m. This outcome confirms that the load increases tire deformation (slip angle) but fundamentally does not significantly alter the maneuverability (turning radius) under conditions where the vehicle has not yet experienced lateral skidding. This research provides a scientific basis for the safe and efficient operation and utilization of small trucks.