Nonlinear dynamics of vibro-impact systems: Theory and experiments

Dynamics of a vibro-impact ground moling system is considered. Due to its structural complexity the dynamic response of an idealised impact oscillator is investigated in the first instance. The model is comprised of an harmonically excited mass simulating the penetrating part of the mole and a visco-elastic slider, which represents the soil resistance. Comparison between experimental and theoretical results shows that the considered model reflects well the dynamics of the vibro-impact system and also the soil resistance curves. A typical nonlinear dynamic analysis has revealed complex behaviour ranging from periodic to chaotic motion. It was found out that the maximum progression is achieved when system responds periodically with the period of external excitation.