• 제목/요약/키워드: magnetostrictive

검색결과 257건 처리시간 0.041초

자기 변형 작동기를 이용한 진동 절연 시스템 (The vibration isolating system using a magnetostrictive actuator)

  • 정학근;박기환
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.276-279
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    • 1997
  • When a magnetostrictive material is exposed to a magnetic field, its geometry changes due to a magnetostrictive effect. The magnetostriction is analogous to the piezoeletricity. The displacement of the magnetostrictive material is proportional to the applied current while that of the piezoelectric material is proportional to the voltage. A magnetostrictive material generates large displacement and higher compressive force compared with a piezoeletric material. These advantages provide a good performance of a vibration isolation of a platform. In this work, it is applied to a driving actuator for vibration isolation of a platform. The properties of a magnetostrictive material are investigated in terms of hysteresis and displacement vs. applied current for a various preload. Modeling of the displacement of the vibration isolating actuator is performed as it behaves as a flow source. A sliding mode controller is designed to demonstrate the ability of the magnetostrictive actuator to reduce the vibration at the platform. The effectiveness of the proposed scheme is demonstrated through experimental works. The experimental results of the vibration of the platform axe presented in terms of time response and frequency response.

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Effects of Elastic Energy of Thin Films on Bending of a Cantilevered Magnetostrictive Film- Substrate System

  • Si, Ho-Mun;Chongdu Cho;Kim, Chang-Boo
    • Journal of Mechanical Science and Technology
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    • 제18권4호
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    • pp.622-629
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    • 2004
  • In this paper, effects of elastic energy of magnetostrictive film on the deflection of a cantilevered film-substrate system are investigated. The total energy including the elastic energy of magnetostrictive film is formulated. And it is minimized to give the curvatures and the position of neutral axis of the cantilevered system. To discuss the effects of the elastic energy of film in a measured system, three magnetostrictive unimorph cantilevers and a bimorph cantilever reported elsewhere are reviewed. It is shown that the assumption, since the thickness of film is much smaller than that of substrate the film elastic energy is negligible, can cause considerable error in evaluating magnetostrictive coefficients. Not the ratio of thicknesses but elastic energies between film and substrate is also shown to play important role in making decision whether the assumption is valid or not.

자왜 재료의 탄성파 속도에 관한 연구 (A Study on the Elastic Wave Velocity of Magnetostrictive Materials)

  • 강국진;노용래
    • 한국음향학회지
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    • 제20권4호
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    • pp.54-61
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    • 2001
  • 자왜 재료는 비선형 자기-탄성 특성을 갖는다고 알려져 있다. 그러나 비선형 특성을 표현하는 자왜 재료의 비선형 구조 방정식을 4차 텐서를 이용하여 유도하였고, 준선형 (quasi-linear)화시킨 압자구조방정식을 이용하여 자왜 재료 내의 파동 방정식을 유도하였다. 유도된 식을 바탕으로 자왜 재료에서 평면파가 자계 방향을 따라 전파될 때의 탄성파 속도를 구하였다. 나아가 자왜 재료 중에서 가장 널리 사용되고 있는 Terfenol-D의 탄성파 속도를 측정하여 본 연구에서 유도한 자왜 재료 비선형 구조 방정식의 타당성을 검증하였다.

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압축 공기 냉각을 이용한 자기 변형 구동기의 열해석에 관한 연구 (A Study on Thermal Analysis for Magnetostrictive Actuator Using Compressed Air Cooling)

  • 곽용길;;황진동;김선호;안중환
    • 한국생산제조학회지
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    • 제18권4호
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    • pp.388-394
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    • 2009
  • Precision positioning system with magnetostrictive actuator(MA) has widely used in manufacturing devices to control the positioning accuracy to meet the high load and stroke requirements. It has many advantage in comparison with piezoelectic actuator; high force, high strain, high efficient etc. But, the performance of Terfenol-D, the commercially available magnetostrictive material, is highly dependent on the prestress, magnetic field intensity and temperature. Therefore, thermal strain of magnetostrictive material obstructs precision position control of magnetostrictive actuator, magnetostrictive actuator is need of cooling system. In this paper, cooling system using compressed cold air is developed and proper temperature and velocity of compressed cold air is studied by thermal analysis according to applied current.

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자왜 Tonpilz 변환기의 음향특성 해석 프로그램 개발 (Program Development for the Underwater-Acoustic Characteristic Analysis of Magnetostrictive Tonpilz Transducer)

  • E. M. Jung;Kim, Jaehwan
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문초록집
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    • pp.370.2-370
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    • 2002
  • Magnetostrictive materials are used low-frequency sonar transmitter instead of piezoelectric materials. But it is difficult to analyze due to the nonlinearity and hysteresis of magnetostrictive materials. This paper deals with the program development based on finite element method to model the magnetostrictive tonpilz transducers and to analyze their acoustic characteristics. (omitted)

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Effect of Permeability and Piezomagnetic Coefficient on Magnetostrictive/Piezoelectric Laminate Composite

  • Wu, Zhiyi;Wen, Yumei;Li, Ping;Yang, Jin;Dai, Xianzhi
    • Journal of Magnetics
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    • 제16권2호
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    • pp.157-160
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    • 2011
  • The magnetostrictive material is magnetized in magnetic field and produces a nonuniform demagnetizing field inside and outside it. The demagnetization is decided by the permeability of magnetostrictive material and its size. The magnetoelectric performances are determined by the synthesis of the applied and demagnetizing fields. An analytical model is proposed to predict the magnetoelectric voltage coefficient (MEVC) of magnetostrictive/piezoelectric laminate composite using equivalent circuit method, in which the nonuniform demagnetizing field is taken into account. The theoretical and experimental results indicate that the MEVC is positively connected with the permeability and the piezomagnetic coefficient of magnetostrictive material. To obtain the maximum MEVC, both the permeability and the piezomagnetic coefficient of magnetostrictive material should be taken into account in selecting the suitable magnetostrictive material.

자왜 Tonpilz 변환기의 음향특성 해석 프로그램 개발 (Program Development for the Underwater-Acoustic Characteristic Analysis of Magnetostrictive Tonpilz Transducer)

  • 정은미;김재환
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문집
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    • pp.705-710
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    • 2002
  • Magnetostrictive materials are used low frequency sonar transmitter instead of piezoelectric materials. But it is difficult to analyze due to the nonlinearity and hysteresis of magnetostrictive materials. This paper deals with the program development for the finite element modeling of magnetostrictive tonpilz transducers and for analyzing their acoustic characteristics. To take into account the nonlinearity of magnetostrictive materials, the magnetic field calculation is separated form the displacement calculation, and a curve fitting is adopted for the nonlinear behavior of the magnetic and mechanical strain fields. At first, the magnetic field is obtained by using a commercial FEM software and the displacement of the transducer is calculated by plugging the obtained magnetic field into forcing term. To verity the accuracy of the developed program, a comparison is made with a commercial code, ATILA.

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자왜재료를 이용한 선형 작동기의 유한요소 해석 (Finite Element Analysis of Magnetostrictive Linear Actuator)

  • 김윤창;김재환
    • 한국소음진동공학회논문집
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    • 제17권4호
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    • pp.356-362
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    • 2007
  • Magnetostrictive materials have been used for linear actuators due to its large strain, large force output with moderate frequency band in the presence of magnetic field. However their performance analysis is difficult because of nonlinear material behaviors in terms of coupled strain-magnetic field dependence, nonlinear permeability, pre-stress dependence and hysteresis. This paper presents a finite element analysis technique for magnetostrictive linear actuator. To deal with coupled problems and nonlinear behaviors, a simple finite element approach is proposed, which is based on separate magnetic field calculation and displacement simulation. The finite element formulation and an in-house program development are illustrated, and a simulation model is made for a magnetostrictive linear actuator. The fabrication and performance test of the linear actuator are explained, and the performance comparison with simulation result is shown. Since this approach is simple, it can be applied for analyzing magnetostrictive underwater projectors and ultrasonic transducers.

자기변형 트랜스듀서의 위상차를 이용한 평판에서의 Lamb파 집속 기초 실험 (Basic Experiment for Lamb Wave Focusing by Phased Magnetostrictive Transducers in a Plate)

  • 이주경;김회웅;이호철;김윤영
    • 한국소음진동공학회논문집
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    • 제21권3호
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    • pp.227-233
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    • 2011
  • The ultrasonic guided wave phased array using magnetostrictive patch transducers is proposed. The magnetostrictive transducer has received much attention because it is cost-effective and capable to generate ultrasonic waves with a simple configuration. However, it has not been used for ultrasonic guided wave phased array applications until now. In this paper, we propose a magnetostrictive transducer based phased array system consisting of a multi-channel function generator, power amplifiers and Lamb wave magnetostrictive transducers. To check the performance of the ultrasonic guided wave phased array, several Lamb wave focusing experiments were carried out in an aluminum plate. The results demonstrated the capability of the developed array to focus the Lamb waves at specific target points.

압축 공기 냉각을 이용한 자기 변형 액추에이터의 위치 추종 성능 향상 (Improvement of Position Tacking Performance of Magnetostrictive Actuator Using Compressed Air Cooling)

  • 곽용길;황진동;김철민;김선호;안중환
    • 한국공작기계학회논문집
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    • 제16권4호
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    • pp.51-56
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    • 2007
  • Precision positioning system with magnetostrictive actuator(MA) has widely used in manufacturing devices to control the positioning accuracy to meet the high load and stroke requirements. It has many advantage in comparison with piezoelectric actuator; high force, high strain, high efficient etc. But, the performance of Terfenol-D, the commercially available magnetostrictive material, is highly dependent on the prestress, magnetic field intensity and temperature. This paper present an experimental investigation of the temperature effect on displacement characteristics of magnetostrictive actuator. In this paper, compressed cold air is proposed to improve of positioning accuracy of magnetostrictive actuator. The compressed cold air cooling system has good cooling effect Experimental results confirming the effectiveness of the proposed cooling system as high precision positioning system are also has presented in this paper.