Response analysis of a nonlinear magnetoelectric energy harvester under harmonic excitation

Magnetostrictive (MS) piezoelectric composites provide interesting possibilities to harvest energy from low amplitude and low frequency vibrations with a relative high energy outcome. In this paper a magnetoelectric (ME) vibration energy harvester has been designed, which consists of two ME transducers a magnetic circuit and a magnetic spring. The ME transducers consist of three layered Terfenol-D and Lead Zirconate Titanate (PZT) laminated composites. The outcoming energy is collected directly from the piezo layer to avoid electrical losses. In the system under consideration, the magnetic forces between the ME transducers and the magnetic circuit introduce additional stiffness on the magnetic spring. The one degree of freedom system is analysed analytically and the corresponding governing equation is solved with the Lindstedt-Poincaré method. The effects of the structure parameters, such as the nonlinear magnetic forces and the magnetic field distribution, are analysed based on finite element analysis for optimization of electric output performances. Investigations demonstrate that 1.56 mW output power across 8 MΩ load resistance can be harvested for an excitation amplitude of 1 mm at 21.84 Hz.