Magnetic amorphous microwires as embedded stress sensors in functional materials
Considerable efforts have been made to develop non-destructive methods for testing internal stress/strain condition of polymer composite materials. A new method of monitoring internal stresses is presented. The method can be referred to as embedded sensing technique, where the sensing element is a glass-coated ferromagnetic microwire with a specific magnetic anisotropy. With a diameter 10-100 microns, the microwire does not affect the structural integrity. When the microwire is remagnetized the sharp voltage is induced which is characterized by high frequency harmonics. The amplitude of these harmonics sensitively depends on various stresses. The experimental results are analyzed using simple magnetostatic models.