Simultaneous broadband vibration isolation and energy harvesting at low frequencies with quasi-zero stiffness and nonlinear monostability

Vibration, as one of the most ubiquitous phenomena, would be a sustainable energy harvesting source to power wireless sensor nodes. However, vibration may be undesirable with detrimental effects such as damage to buildings, discomfort to passengers, etc. So far, the simultaneous broadband energy harvesting and vibration isolation at low frequencies between 0 and 15 Hz is still an open issue. Motivated by this, we propose a novel device with a quasi-zero-stiffness (QZS) support through cam–roller–spring mechanism (CRSM) and multiple nonlinear monostable piezoelectric energy harvesters. A semi-analytical electromechanical model considering AC/DC circuits is developed and validated. Simulation results show that when the high-energy branches of the proposed device with six nonlinear monostable harvesters are triggered, the peak power and energy harvesting frequency bandwidths are respectively increased by up to 69.29% and 1.22 times compared with those of its counterpart with linear harvesters. Furthermore, these are achieved at frequencies lower than 15 Hz without the sacrifice of low force transmissibility and isolation frequencies. Parametric studies indicate that except for the harvester damping, no matter how other parameters change, the superiority of the proposed device exists compared with its linear counterpart. It can be potentially used in building a smart floor tile with dual functions of energy harvesting to power wireless sensor nodes for footfall tracking or light-emitting diodes, and vibration isolation to enhance pedestrian comfort and safety.