Multi‐mode model of a piezomagnetoelastic energy harvester under random excitation

The transformation of ambient vibrational energy into electric energy through the use of piezoelectric energy harvesting devices has been the subject of numerous investigations [1]. A commonly studied energy harvesting device performing especially well under broadband excitation, is the piezomagnetoelastic energy harvester investigated by Erturk et al . [2], which is usually discretised for the fundamental vibration mode resulting in a single‐mode model. This contribution presents the study of a multi‐mode model of the piezomagnetoelastic energy harvester under random excitation. The probabilty density function (PDF) is computed to be the solution of the corresponding Fokker‐Planck equation using a Galerkin type method [3,4]. Based on the PDF, the resulting voltage variance is computed as a measurement for the expected power output as demonstrated in [5]. The results of the multi‐mode model are then compared with the results of the single‐mode model. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)