Energy harvesting efficiency of a quasi-zero stiffness energy harvester

In this paper, a study on modelling energy harvesting efficiency of a quasi-zero stiffness system is presented. Mechanical characteristics of the system are identified, and the effect of its stiffness and geometry on the function describing energy potential barrier is determined. It has been shown numerically that an increase in equivalent stiffness of the quasi-zero stiffness system limits the potential barrier width. On the other hand, increased the spacing between compensating springs results in increased barrier width. Simulation results of the quasi-zero stiffness system are compared with those obtained for a triple-well system with permanent magnets. Based on mathematical models, multi-color diagrams depicting the largest Lyapunov exponent are plotted. The effect of selected values of external excitation frequency and amplitude on the efficiency of energy harvesting is determined. The rms value of time sequence is taken as a measure of the energy harvesting efficiency. Obtained numerical results are plotted as phase trajectories.