Numerical Magneto-Mechanics of Embedded Magnetostrictive Composite Sensors Available to Purchase

Numerical models are generated for magneto-mechanical analysis of Terfenol-D embedded in a carbon fiber laminate with delaminations. The modeling is broken down into three stages; each having studies to observe the affect of the controlling parameters on the magnetic signature. The first stage, which is presented in this paper, involves modeling the magnetostrictive layer and excitation coil. This stage contains three preliminary studies to observe the affect of the controlling parameters on the magnetic flux density. The modeling geometry and the magneto-mechanical properties of the magnetostrictive particle (MSP) layer, Terfenol-D, were also defined. Study I consisted of models with 1, 15, 30, and 100 subdomains in the Terfenol-D layer to simulate particulate actuation. The results revealed that subdomain refinement has a significant affect, altering the magnetic flux density by at least one order of magnitude. Furthermore, the study revealed that the magnitude of the magnetic flux density converged at 15, 30, and 100 divisions. Study II was conducted to investigate the affect of the alternating current frequency on the magnetic flux density magnitude. The frequency was varied from 100 Hz to 3000 Hz on all the models. The results from the frequency variation study revealed that flux density of the Terfenol-D modeled with the 15, 30, and 100 divisions was not significantly affected by the change in frequency from 100–3000 Hz. Study III uses Ampere’s Law and a magnetostriction equation for the magnetic flux density to analytically validate the numerical results from the flux density plot. The initial results reveal that the numerical results follow the correct trend, but the magnitudes are being validated. A preliminary model for the second stage, which consists of modeling the Terfenol-D layer embedded in a carbon fiber laminate, is shown. Experimental samples were also made to validate the numerical results in the future. These samples are made of unidirectional prepreg carbon fiber embedded with Terfnol-D. They have varying internal delaminations, ply orientations, and number of plies. The results presented in this work are preliminary, and will be used as a foundation for continuing this research.