Design and Development of Magnetostrictive Actuators and Sensors for Structural Health Monitoring

Abstract

Carbon Fibre Reinforced Polymer composite (CFRP) is widely used in the aerospace industry, but is prone to delamination, which is a major causes of failure. Structural Health Monitoring (SHM) systems need to be developed to determine the damage occurring within it. Our motivation is to design cost-effective new sensors and a data acquisition system for magnetostrictive structural health monitoring of aerospace composites using a simple RLC circuit. The developed system is tested on magnetostrictive FeSiB and CoSiB actuator ribbons using a bending rig. Our results show detectable sensitivity of inductors as low as 0.6 μH for a bending rig radii between 600 to 300 mm (equivalent to 0.8 to 1.7 mStrain), which show a strain sensitivity resolution of 0.01 μStrain (surface area: ~36 mm2). This value is at the detectability limit of our fabricated system. The best resolution (1.86 μStrain) was obtained from a 70-turn copper (~64 μH) wire inductor (surface area: ~400 mm2) that was paired with a FeSiB actuator.

New Type of Linear Magnetostrictive Motor Designed for Outer Space Applications, from Concept to End-Product

“…The mechanical bias is produced by the pre-tensioning spring (5), with five turns and an elastic constant of 5000 N/m. The ring (6), made of a material with low magnetic remanence, grips the active GMM core (1) so that the lower magnet ( 4) is in its immediate vicinity. The ring ( 6) is split (a gap of 0.8 mm) to not short-circuit the coil, as is the rod (13), which aims to fix the components of (A).…”

“…For instance, [5] reported on an ultrasonic GMA using a compound of rare earth elements, including Terfenol-D, which was fabricated and tested. In [6], an efficient damage-detection system for structural health monitoring in composites, with potential applications in the aerospace industry to detect and monitor cracks in critical aerospace components, is presented. Huang et al proposed a model of a GMA for which the principal parts consist of a cylindrical Terfenol-D rod, an activation coil, an enclosing permanent magnet, a pre-stressed bolt, and a spring washer.…”

Spin Orientation and Magnetostriction of Tb1−xDyxFe2 from First Principles

“…Equations (11) and (12) show how the anisotropy and magnetoelastic constants can be obtained from the CF coefficients B lm and their strain derivatives dB lm /dε X . These are the quantities that we calculate from first principles within the yttrium-analog method [25].…”

“…While remarkable for its magnetostriction, Terfenol-D does suffer from two drawbacks: it is brittle [10] and, due to its reliance on the critical heavy rare earths (REs) Tb and Dy, it is expensive [11]. Intense research has been aimed at finding new materials with reduced or zero RE content and better mechanical properties, with the notable successes of Fe-Ga and Fe-Al (Galfenol and Alfenol) [12,13].…”

Simple Device to Measure Pressure Using the Stress Impedance Effect of Amorphous Soft Magnetic Thin Film

“…In the case of a thin-film device, typically a sandwich of a non-magnetic highly conductive layer between soft ferromagnetic layers, e.g., FeSiB/Cu/FeSiB or CoSiB/Cu/CoSiB, with a total thickness in the range of several µm is used [22,23]. As for applications other than as a strain gauge, the possibility of using it as a force sensor, for structural health monitoring, or a pressure sensor has been mentioned [24,25]. Nevertheless, no actual pressure measuring device, using this effect, has been presented yet.…”