Energy harvesting in a nonlinear piezomagnetoelastic beam subjected to random excitation

• Bistable piezomagnetoelastic generator subjected to random excitations is analyzed.
• Performance is enhanced when system oscillates around all stable equilibrium points.
• Numerical and experimental approaches show good qualitative agreement.
• A relationship between the variance of excitation and potential energy is defined.
• A desired region, where the performance of bistable system is enhanced, is defined.

This work addresses the influence of nonlinearities in energy harvesting from a piezomagnetoelastic structure subjected to random vibrations. Nonlinear equations of motion that describe the electromechanical system are given along with theoretical simulations. The numerical analysis presents a comparison between the voltage provided from a linear, nonlinear bistable and nonlinear monostable systems due to random vibration. Experimental performance of the generator exhibits qualitative agreement with the theory, showing an enhancement of piezoelectric power generation in a bistable system when it vibrates around both stable equilibrium points. A relationship between variations in the excitation and a bistable system response is established from numerical simulations, defining a region of enhanced power generation when compared to the linear and nonlinear monostable cases.