Magnetostrictive patch sensor system for battery-less real-time measurement of torsional vibrations of rotating shafts

• Published in: Journal of sound and vibration Vol. 414; pp. 245 - 258
• Main Authors: Lee, Jun Kyu, Seung, Hong Min, Park, Chung Il, Lee, Joo Kyung, Lim, Do Hyeong, Kim, Yoon Young
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 03.02.2018; Elsevier Science Ltd
• Subjects: Batteries; Bonding strength; Deformation; Liquefied petroleum gas; Magnetostriction; Magnetostrictive patch sensors; Magnets; Measurement; Noncontact vibration sensors; Real time; Rotating shafts; Rotating ship shafts; Rotation; Strain gauge; Strain gauges; Strain hardening; Studies; Telemetry; Time measurement; Torsion; Torsional vibration; Vibration measurement; Vibration monitoring; Magnetostrictive patch sensors; Torsional vibration; Noncontact vibration sensors; Rotating ship shafts; Strain gauge
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1016/j.jsv.2017.11.023

Real-time uninterrupted measurement for torsional vibrations of rotating shafts is crucial for permanent health monitoring. So far, strain gauge systems with telemetry units have been used for real-time monitoring. However, they have a critical disadvantage in that shaft operations must be stopped intermittently to replace telemetry unit batteries. To find an alternative method to carry out battery-less real-time measurement for torsional vibrations of rotating shafts, a magnetostrictive patch sensor system was proposed in the present study. Since the proposed sensor does not use any powered telemetry system, no battery is needed and thus there is no need to stop rotating shafts for battery replacement. The proposed sensor consists of magnetostrictive patches and small magnets tightly bonded onto a shaft. A solenoid coil is placed around the shaft to convert magnetostrictive patch deformation by shaft torsional vibration into electric voltage output. For sensor design and characterization, investigations were performed in a laboratory on relatively small-sized stationary solid shaft. A magnetostrictive patch sensor system was then designed and installed on a large rotating propulsion shaft of an LPG carrier ship in operation. Vibration signals were measured using the proposed sensor system and compared to those measured with a telemetry unit-equipped strain gauge system. •A magnetostrictive torsional vibration sensor (MTVS) is proposed for shafts.•The MTVS can measure torsional vibrations of rotating shafts without power supply.•Torsional vibration is successfully measured in an LPG carrier ship by the MTVS.•Its frequency spectrum is found to match well with that by a strain gauge.