Improving energy harvesting from impulsive excitations by a nonlinear tunable bistable energy harvester

Abstract

This paper proposes a novel prototype of tunable bistable energy harvester (TBEH) coupled to a grounded and weakly damped linear primary structure. Based on buckling beam theory and generalized Hamiltonian principle, the equivalent mathematical model of the proposed TBEH system is presented and numerically simulated. A thorough sensitivity analysis concerning the buckled factor, the mass ratio, magnitude of impulse and the impulse period is studied to provide design insights for dynamic optimization of the TBEH system excited by varying impulsive excitations. The influences of a single impulse and repeated impulses on the vibration suppression and energy harvesting performance of TBEH system are investigated, respectively. Furthermore, the dynamics of the primary structure and TBEH and percentage of transient total energy in the TBEH are presented. The results show that maximizing measures of vibration energy absorption and harvesting can be optimized by tuning the sensitive parameters of the TBEH system. Compared with the pure cubic case, the tunable buckled TBEH shows remarkable advances in broadband vibration absorption and fast energy transfer. Finally, the confirmatory prototype experiment is conducted to validate the theoretical results. The measured experimental results are in good agreements with the theoretical analysis. The proposed TBEH with excellent energy capture and conversion is a potential alternative for powering miniature wireless sensor networks.