Evaluation of the dynamic characteristics and damping of a vehicle’s suspension using the free-fall method

This paper proposes a diagnostic method and a mathematical framework for evaluating the operational processes and damping properties of a vehicle suspension based on the experimental free-fall method. To ensure the reproducibility of the tests, a special mobile device (trolley) was designed and manufactured. The structural analysis of the trolley under static loading was performed using the finite element method in SolidWorks Simulation. Experimental studies were carried out on free-fall tests from a height of 12 cm for two vehicle configurations: the base ZAZ-1102 ‘Tavria’ with an internal combustion engine (ICE) and its modified version with an electric drive (EV). Based on the experimental diagrams, logarithmic damping decrements and viscous resistance coefficients were determined, and differential equations for damped oscillations were derived. The method made it possible to quickly identify a qualitative deficiency in the rear-right shock absorber, evidenced by a markedly slower amplitude decay (5 vs. 3 oscillations) relative to the rear-left side.