Speaker
Description
Measuring changes in physical quantities without direct contact is still challenging in sensor applications. Especially in the case of structural member monitoring, it is quite difficult to substitute conventional electrical strain gauges with contactless technology.
A promising solution can be found in magnetically bistable glass-coated microwires. The small dimensions of microwires make it possible to attach them to different kinds of materials or even embed them in nonmetallic materials. The presented experimental approach of contactless monitoring is composed of two basic elements. The first element is the bistable glass-coated microwire, which can be considered as the passive part. The second part, also known as the active segment, is made of two coils – an excitation coil and a sensing coil. While the excitation coil generates an AC magnetic field necessary for the microwire's magnetic reversal process (excitation of the microwire), the sensing coil is used to capture the signal from the microwire. Since the microwire is sensitive to the applied mechanical stress, it can be used for contactless deformation monitoring [1].
Moreover, the magnetically bistable character of the glass-coated microwire allows the separation of the influence of additional parasitic external magnetic field from the deflection measurement. Because of that, the presented approach is suitable for contactless deformation monitoring of metallic materials with a ferromagnetic nature and in conditions with additional external magnetic field influence [2].
Acknowledgements
This work was supported by the Slovak projects APVV-15-0777, APVV-16-0079, Slovak VEGA grant No. 1/0129/20 and VEGA 1/0180/23.
References
[1] M. Al Ali, P. Platko, V. Bajzecerova, S. Kmet, L. Galdun, A. Spegarova, R. Varga, “Monitoring the strain of beech plywood using a bistable magnetic microwire,” Sens. Actuators A: Phys. 326, 112726, 2021. doi: 10.1016/j.sna.2021.112726.
[2] M. Al Ali, P. Platko, V. Bajzecerova, S. Kusnir, S. Kmet, S. Nalevanko, A. Spegarova, L. Galdun, R. Varga, “Application of bistable glass-coated microwire for monitoring and measuring the deformations of metal structural members,” Measurement 208, 112458, 2023. doi: 10.1016/j.measurement.2023.112458.
