Analysis of magnetopiezoelastic energy harvesters under random excitations: an equivalent linearization approach

Abstract

This paper develops an equivalent linear model for piezomagnetoelastic energy harvesters under broadband random ambient excitations. Piezomagnetoelastic harvesters are used for powering low power electronic sensor systems. Nonlinear behaviour arising due to the vibration in a magnetic field makes piezomagnetoelastic energy harvesters different from the more classical piezoelastic energy harvesters. First numerical simulation of the nonlinear model is presented and then an equivalent linearization based analytical approach is developed for the analysis of harvested power. A cosed-form approximate expression for the ensemble average of the harvested power is derived. The equivalent model is seen to capture the details of the nonlinear model and also provides more details to the behaviour of the harvester to random excitation. Our results show that it is possible to optimally design the system such that the mean harvested power is maximized for a given strength of the input broadband random ambient excitation.