Abstract

The coupling between the self-generated magnetic and acoustic behavior of magnetostrictive materials under load is explored. Results from fatigue loading of magnetostrictive ferromagnetic materials suggests that the acoustic response is sensitive to internal stress rates. Acoustic wave propagation can travel in the material with less damping than the magnetic behavior that created it. This suggests an ability to measure this behavior remotely. The hypothesis is that this noise is related to piezomagnetic behavior and the discontinuous nature of local changes in magnetic permeability. Various materials were tested in compression and tension. Non-magnetostrictive specimens do not exhibit this behavior. Specimens with smaller magnetostriction exhibit the behavior with less intensity. A reduction of this behavior does occur as the loading frequency is increased. Understanding the sources of this noise could yield a unique method for characterizing the early damage state of ferromagnetic materials and become the basis for smart sensor materials for characterizing structures.

How to Cite:

Horne, M., Amos, P. & Madaras, E., (2019) “Acoustic response of dynamic piezomagnetic behavior”, Review of Progress in Quantitative Nondestructive Evaluation .