Ultrasonic guided wave sensing performance of a magnetostrictive transducer using Galfenol flakes-polymer composite patches

作者：Yoo Byungseok^*; Na Suok Min; Flatau Alison B; Pines Darryll J

来源：Journal of Applied Physics, 2015, 117(17): 17A916.

DOI：10.1063/1.4916811

In this paper, we investigate ultrasonic guided wave (GW) sensing performance of a magnetostrictive composite patch sensor (MCPS) in use of a structural health monitoring system for metallic plates. A composite patch of the MCPS consisted of magnetostrictive powders and binding epoxy, where flake-and granular-type Galfenol and spherical nickel particles were considered to examine the effect of particle shape on sensing capability and directional sensitivity. Galfenol flakes with the surface parallel to the (200) crystallographic planes exhibit good field sensitivities in magnetic and magnetostrictive properties when an in-plane field is applied. Shape anisotropy disappears for the conventional spherical shape, accompanying with a large magnetizing field and poor field sensitivity. The 60-kHz GW was successfully captured by the three different MCPSs. Among them, the MCPS with the Galfenol flakes showed the best sensing performance because of their excellent field sensitivities in magnetization and magnetostriction. In addition, the composite patch was configured into a uniaxial comb shape to promote the magnetic shape anisotropy feature of the magnetostrictive patch by itself. Due to the unique configuration of the Galfenol composite patch, the equivalent MCPS presented outstanding directional sensitivity for the GWs propagating along the orientation of the comb fingers.

• 出版日期2015-5-7