Parametric numerical study on a novel energy harvester using iron-gallium alloy and strain response

Abstract

With the aim of contributing to efficient structural health monitoring approaches, this study proposes a micro energy-harvesting strain gauge, utilizing iron-gallium alloy, capable of generating electrical energy from dynamic strain responses. The iron-gallium alloy is a ductile magnetostrictive material with a high piezomagnetic constant, good machinability, and a large inverse magnetostrictive effect by which magnetization can be varied by mechanical stress. The device has a simple structure: a combination of a flat plate of iron-gallium alloy and a stainless steel frame, the former attached to the latter. A variation in stress applied at the alloy plate yields a time variation of the flux generating a voltage on the wound coils. The strain data is also measured at the same time. To achieve high efficiency in both power generation and deformation measurement, effective design for the novel device is required. Therefore, prototype finite element models were constructed based on the number of commercial designs available on the market. Then, parametric studies were carried out by changing the shapes, heights, and widths of the devices in order to examine their possible effects on the deformation behavior of the proposed structure. Finally, design procedures for the proposed device were recommended based on these numerical studies.