• Journal of Magnetics
• /
• 제13권1호
• /
• pp.34-36
• /
• 2008

For the measurement of the magnetic field distribution with high spatial resolution and high accuracy, the magnetic field sensing probe must be non-magnetic, but the MFM probe and sub-millimeter-meter size Hall probe use a ferromagnetic tip and block, respectively, to increase the sensitivity. To overcome this drawback, we developed a micro-size search coil magnetometer which consists of a single turn search coil, Terfenol-D actuator, scanning system, and control software. To reduce the noise generated by the stray ac magnetic field of the actuator driving coil, we employed an even function $\lambda$-H magnetostriction curve and lock-in technique. Using the developed magnetometer, we were able to measure the magnetic field distribution with a magnetic field resolution of 1 mT and spatial resolution of $0.1mm{\times}0.2mm$ at a coil vibration frequency of 1.8 kHz.

• 한국정밀공학회지
• /
• 제21권5호
• /
• pp.174-181
• /
• 2004

This paper presents the development of a magnetostrictive microactuator. The structural and functional requirements are as follows: it must be a millimeter structure and must achieve controllable displacement with nanometer resolution. Finite Element Analysis(FEA) is used to determine the structure with the most uniform and highest magnetic flux density along the Terfenol-D rod. The microactuator prototype 1 is designed and made based on the FEA. It is observed that the microactuator show some level of hysteresis and that it produces 25 newton in force and 3 ${\mu}{\textrm}{m}$ in displacement with 1.5 amperes of current, and resolution of 250 nm per 0.1 amperes. To improve the performance of the microactuator prototype 1, microactuator prototype 2 is made again with a permanent magnet (PM). It is observed that the microactuator prototype 2 gene.ates 3.3 ${\mu}{\textrm}{m}$ in displacement with 0.9 amperes of current. It means that the microactuator prototype 2 performs better than the microactuator prototype 1.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2000년도 추계학술대회논문집
• /
• pp.249-255
• /
• 2000

The design and test of an magnetostrictive linear motor(MLM) that operates based on self-moving cell concept is presented. The moving cell is composed of Terfenol-D linear actuator and a ring structure, and a cell train is constructed by connecting two cells in series. Since this motor uses the stroke of Terfenol-D actuators and friction force of the cells, it can essentially produce long stroke and large force. The overall performance of the MLM was measured in terms of speed and force. The pushing force is directly related with the friction force. This work is a proof-of-concept stage and investigation is necessary for realistic application.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2001년도 추계연구발표회 논문개요집
• /
• pp.112-113
• /
• 2001

• Journal of Magnetics
• /
• 제20권4호
• /
• pp.347-352
• /
• 2015

The magnetoelectric (ME) characteristics for Terfenol-D/PZT laminate composite dependence on bias magnetic field is investigated. At low frequency, ME response is determined by the piezomagnetic coefficient $d_{33,m}$ and the elastic compliance $s_{33}^H$ of magnetostrictive material, $d_{33,m}$ and $s_{33}^H$ for Terfenol-D are inherently nonlinear and dependent on $H_{dc}$, leading to the influence of $H_{dc}$ on low-frequency ME voltage coefficient. At resonance, the mechanical quality factor $Q_m$ dependences on $H_{dc}$ results in the differences between the low-frequency and resonant ME voltage coefficient with $H_{dc}$. In terms of ${\Delta}E$ effect, the resonant frequency shift is derived with respect to the bias magnetic field. Considering the nonlinear effect of magnetostrictive material and $Q_m$ dependence on $H_{dc}$c, it predicts the low-frequency and resonant ME voltage coefficients as a function of the dc bias magnetic field. A good agreement between the theoretical results and experimental data is obtained and it is found that ME characteristics dependence on $H_{dc}$ are mainly influenced by the nonlinear effect of magnetostrictive material.

• 비파괴검사학회지
• /
• 제35권3호
• /
• pp.215-220
• /
• 2015

최근 널리 사용되는 모든 비파괴검사 기술 중 적외선열화상 카메라는 점차 적용 범위를 확대하고 있다. 초음파적외선 열화상은 절대온도 0 K 이상의 모든 물체가 방출하는 적외선 에너지를 검출하여 검사자가 볼 수 있는 화상으로 이미지를 만들어 검사하는 기술에 초음파를 접목하여 결함 부위만을 검출하는 방법으로 비접촉으로 넓은 범위를 빠른 시간에 검사할 수 있는 장점이 있는 기술이다. 본 연구에서는 고유주파수를 변화할 수 있는 터패놀-D 소재의 가변초음파 가진검사 방법을 이용하여 결함 검출의 적용가능성을 연구하였다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2012년도 춘계학술대회 논문집
• /
• pp.1069-1070
• /
• 2012

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2013년도 춘계학술대회 논문집
• /
• pp.1187-1188
• /
• 2013

• 한국자기학회지
• /
• 제4권4호
• /
• pp.303-306
• /
• 1994

본 논문에서는 초자왜소자 $Terfenol-D(Tb_{0.3}Dy_{0.7}Fe_{1.9~1.95})$의 인가자장에 따른 자왜의 변화를 측정하였고, 잔류 자왜 및 초자왜소자의 온도 상승에 의한 열팽창 변형의 영향을 조사 하였다. 또한 초자왜소자에 3.5~14 MPa의 압축 응력을 인가하면서 자왜의 변화를 조사하였다. 그 결과는 인 가 압축 응력이 7 MPa인 경우 1500 Oe의 자장에서의 자왜는 1000 ppm이었으나 압축 응력을 가하지 않은 경 우는 400 ppm이었다. 또한 인가 압축 응력이 커짐에 따라서 자왜가 포화되는 자장의 크기도 커졌다. 잔류 변형과 히스테리시스가 관측되었으며, 따라서 액츄에이터로 이용할 때는 이를 보상하는 기구가 필요하며 또 한 열팽창에 의한 변형도 액츄에이터 응용시에는 고려하여야 한다.

• 한국정밀공학회지
• /
• 제15권11호
• /
• pp.58-66
• /
• 1998

A low power consuming laser scanning vibrometer is studied for its development. For its optical system, a laser interferometer is constructed to use the Doppler effect. In order to reduce the driving power of the scanning system, a small displacement of the scanning system is produced, which is achieved by using a magnetostrictive actuator. A sufficient rotating angle of the scanning system is obtained by using an amplified displacement from the resonant phenomena of a second order mechanical system composed of a mass and spring. The control of the magnetostrictive actuator using a Terfenol-D is performed without using a feedback system to help reduce the power consumption. The vibration analysis is made for the sinusoidal scanning input to have the space domain information from the time domain of the velocity of a vibration object. As a partial work of development of a tow power consuming laser scanning vibrometer, in this work, a scanning system which has the above features is developed and experimentally investigated. For the purpose of the optical system calibration, the vibration measurement for one axis is presented and the future works are discussed.