Experimental Inter-Modal Targeted Energy Transfer in a cantilever beam undergoing Vibro-impacts

Abstract

This work experimentally demonstrates inter-modal targeted energy transfer (IMTET) in a cantilever beam system with vibro-impacts. IMTET is known to achieve non-resonant rapid energy transfer from low-to-high frequency structural modes in mechanical systems. While previous works have computationally demonstrated the efficacy of IMTET, the theory and methodology supporting IMTET still lacks experimental verification. To address this task, an experiment is constructed whereby a steel beam is clamped at one end and excited at the other, and steel tips with clearances anchored to a host fixture serve as vibro-impacts (VIs) which induce non-resonant energy redistribution within the modal space of the beam. The system is modeled as an Euler–Bernoulli cantilever beam which is discretized by the finite element method, and the VI forces are simulated by a single-sided dissipative Hertzian contact model. The time-responses, modal dissipation ratios, and characteristic decay times measured in the experiment are compared to the computational models to confirm the validity of the theoretical predictions. It is found for both the experiment and computational model that the VIs transfer energy from low frequency structural modes to high frequency ones which, in turn, results in a substantial reduction in the characteristic decay time and thus confirms the efficacy of IMTET in practice. The diverse potential applications of IMTET in engineering practice are then emphasized.