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조승현;한순우;박찬일;김윤영
- 대한기계학회논문집A
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- 제30권3호
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- pp.342-348
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- 2006
A new magnetostrictive patch array transducer for the generation and detection of torsional waves is developed fur the on-line health monitoring of rotating shafts. Even though the torsional wave is useful in nondestructive evaluation due to its non-dispersive property, a transducer generating torsional waves in rotating shafts has not been developed so far. In this research, a torsional wave transducer using the magnetostrictive effect is newly developed. By bonding an away of magnetostrictive rectangular patches on the outer surface of the shaft at an oblique angle of $45^{\circ}$ and encircling the array by a solenoid coil, we have successfully generated and measured torsional waves by the developed transducer. Several experiments were carried out to check the transducer performance.
https://doi.org/10.3795/KSME-A.2006.30.3.342 인용 PDF KSCI

김윤영;조승현;이주승;선경호
- 한국소음진동공학회:학술대회논문집
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- 한국소음진동공학회 2004년도 추계학술대회논문집
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- pp.423-427
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- 2004
In this work, we propose a new ultrasonic damage inspection method in plate structures. The proposed method employs an OPMT (Orientation-adjustable Patch-type Magnetostrictive Transducer) in order to make the ultrasonic waves focused on the specific target point. For experiments, virtual grid points were set up at every 50 mm in an aluminum plate and two OPMTs were used for inspection. If there exists a crack in a plate, the reflected Lamb wave from the crack is measured in addition to the direct waves from the transmitting transducer to the receiving transducer.
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이주승;조승현;선경호;김윤영
- 한국소음진동공학회:학술대회논문집
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- 한국소음진동공학회 2004년도 춘계학술대회논문집
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- pp.153-158
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- 2004
The coupling phenomenon between stress and magnetic induction, known as magnetostriction, has been successfully applied to generate and measure elastic waves. Most applications of this phenomenon thus far, however, are rather limited to cylindrical ferromagnetic waveguides. The main objective of this work is to develop a new patch-type, orientation-adjustable magnetostrictive transducer that is applicable for non-cylindrical, non-ferromagnetic waveguides. The existing patch-type transducer consisting of a ferromagnetic patch and a racetrack coil is useful to generate elastic waves only in one specific direction once the patch is bonded to a test specimen. However, the proposed transducer can transmit and receive elastic waves in any direction only with one patch at a given location. The proposed magnetostrictive transducer consists of a circular nickel patch, a figure-of-eight coil, and a couple of bias permanent magnets. Because of the unique configuration of the transducer, the propagating direction of the generated waves can be freely controlled since the set of bias magnets and the coil is not bonded to the magnetostrictive patch. In this work, the characteristics of the proposed transducer were investigated experimentally.
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승홍민;김윤영
- 한국소음진동공학회:학술대회논문집
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- 한국소음진동공학회 2014년도 추계학술대회 논문집
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- pp.548-549
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- 2014
Omni-directional shear-horizontal magnetostrictive patch transducers have a disadvantage that magnetic flux leakage into the plate when it is installed on a ferromagnetic plate. The leakage produces poor transduction efficiency and unwanted wave mode excitation which should be avoided in guided wave inspections of large plate-like structures. In order to resolve these problems, we newly developed a method to reduce the leakage into the plate. In the method, the patch and the magnet are vertically lifted off and their optimal positions are determined by numerical simulations. Also, the verification of the developed method is successfully verified by experiments.
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