Experimental detection of mechanical deformations exploiting electromechanical effects

• Published in: Journal of thermal stresses Vol. 47; no. 11; pp. 1425 - 1449
• Main Authors: Csernak, Gabor, Miklos, Akos, Magyar, Balint, Henap, Gabor, Virosztek, Attila, Wohlfart, Richard, Stepan, Gabor
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 01-11-2024; Taylor & Francis Ltd
• Subjects: Copper wire; Deformation effects; Deformation-induced voltage; Electric potential; electro-mechanical coupling; Electromagnetic fields; flexoelectricity; Magnetic properties; Magnetoelastic effect; magnetoelasticity; Measurement methods; sensor-free detection of vibrations; Shock waves; thermo-mechanical coupling; Voltage
• ISSN: 0149-5739; 1521-074X
• DOI: 10.1080/01495739.2024.2400195

The present paper discusses experimental results concerning the deformation-induced generation of electric potential difference in steel specimens. According to our observations, voltages in the order of 10 microVolts can be measured between points on the surfaces of steel bodies during mechanical deformation. Three different experimental set-ups were used to determine the properties of the phenomenon, carefully excluding the influence of possible external electromagnetic fields. In order to exclude thermoelectric effects, a special steel specimen was fabricated. Further experimental campaigns were conducted with long, thin metallic rods in two different set-ups: the generation of voltage was measured during the traveling of longitudinal shock waves and during bending vibrations of the specimens. The results indicate that the variation of the magnetization of the material - the magnetoelastic effect - plays an important role in the phenomenon, but thermoelectricity also contributes to the measurable voltage signals. The electromechanical effect identified in the present paper may have several applications in measurement technology. The most relevant advantage of the applied measurement methods is that these are essentially sensor-free, since the mechanical vibrations can be detected by simply soldering, welding, or pressing copper wires to the examined steel specimen.