On the Effect of Hardening/Softening Structural Non-linearities on an Array of Aerodynamically Coupled Piezoelectric Harvesters

In this work, we study the non-linear dynamic response of two vertically-arranged aero-piezoelastic harvesters. The numerical framework consists of the following: i) an aerodynamic model based on the unsteady vortex-lattice method; ii) a three degree-of-freedom lumped-parameter model for each harvester; iii) an inter-model connection to exchange information between models at each time step; and iv) a numerical scheme based on Hamming’s fourth-order predictor–corrector method to integrate all the governing equations. Particularly, the effect of nonlinear hardening/softening springs on the harvested output power is investigated. Among the results obtained, an interesting finding is that hardening springs yield larger LCO amplitudes and higher harvested power than softening springs.