Nonlinear energy pumping under transient forcing with strongly nonlinear coupling: Theoretical and experimental results

This paper aims to experimentally verify the theoretical effects of energy pumping especially with external excitation. Energy pumping is irreversible transfer of energy from a linear or linearized structure to a nonlinear energy sink (NES) with relatively small mass. This NES can be used as a nonlinear absorber. This phenomenon is analyzed for different kinds of excitation. In suitable range of amplitudes of the external forcing, the damped system exhibits quasiperiodic vibrational regime rather than periodic responses reported in earlier publications. This regime can be explained by using nonlinear normal mode theory. Mechanical experiments confirm the theoretical results by using a small building model. In particular, the case of earthquake excitations is investigated.