• 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.

• 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)

• Structural Engineering and Mechanics
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• 제17권3_4호
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• pp.303-329
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• 2004

Magnetostrictive materials are routinely employed as actuator and sensor elements in a wide variety of noise and vibration control problems. In infrastructural applications, other technologies such as hydraulic actuation, piezoelectric materials and more recently, magnetorheological fluids, are being favored for actuation and sensing purposes. These technologies have reached a degree of technical maturity and in some cases, cost effectiveness, which justify their broad use in infrastructural applications. Advanced civil structures present new challenges in the areas of condition monitoring and repair, reliability, and high-authority actuation which motivate the need to explore new methods and materials recently developed in the areas of materials science and transducer design. This paper provides an overview of a class of materials that because of the large force, displacement, and energy conversion effciency that it can provide is being considered in a growing number of quasistatic and dynamic applications. Since magnetostriction involves a bidirectional energy exchange between magnetic and elastic states, magnetostrictive materials provide mechanisms both for actuation and sensing. This paper provides an overview of materials, methods and applications with the goal to inspire novel solutions based on magnetostrictive materials for the design and control of advanced infrastructural systems.

• 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.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1129-1130
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• 2011

• 한국정밀공학회지
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• 제28권4호
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• pp.398-403
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• 2011

Terfenol-D is one of several magnetostrictive materials with property of converting energy into mechanical motion, and vice versa. Magnetostriction is the property that causes certain ferromagnetic materials to change shape in a magnetic field. Terfenol-D is said to produce giant magnetostriction, strain greater than any other commercially available smart material. In this paper, fundamental characteristics analysis of giant magnetostrictive materials(Terfenol-D) has been investigated. The magnetic field analysis is carried out by using finite element method simulation ANSYS. The results show 223N in force and 9.5T in maximum magnetic flux density and 7.56 $10^6A/m$ in maximum magnetic field intensity 1A current. Through the analysis, basic data of Terfenol-D for the application of mechanical system are obtained.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2002년도 동계연구발표회 논문개요집
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• pp.138-139
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• 2002

Polymer-bonded magnetostrictive composites have some distinct advantages over conventional type materials in being cost effective and suitable for high frequency applications due to high electrical resistivity. Composites of rare earth based alloys were reported to show good magnetostrictive characteristics both in static and dynamic conditions [1]. It was originally thought that the application of the polymer-bonding technique to transition metal alloys is straightforward. (omitted)

• 한국정밀공학회지
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• 제29권11호
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• pp.1214-1220
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• 2012

Vibration assisted cutting (VAC) is one of the promising methods for precision machining, which has been normally equipped with piezoelectric materials. In this paper, a feasibility of applying magnetostrictive materials to VAC as a cutting device instead of piezoelectric materials was studied. For this, the vibrational characteristics of a magnetostrictive material was investigated with respect to a coil design, a preload, and the effects of a biasing and an exciting magnetic fields. The output strain of a magnetostrictive material is restricted due to an increasing inductive impedance as the exciting frequency increases and the heat of coil, etc. Through the experimental results, it was found that the biasing and the exciting magnetic field affected the output performance significantly but not the preload. In conclusion, the magnetostrictive material could be used only in the low frequency range but not a good candidate for high frequency actuating application.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.1066-1068
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• 1993

Magnetostrictive materials are deformed by applying magnetic fields as electrostrictive materials are deformed by applying electric fields. The GMA(Giant Magnetostrictive Alloy: Terfenol-D) shows larger strain and force compared with piezoceramics and SMA. It is expected that the GMA replaces the piezoceramics in various applications. In this paper, the basic properties of GMA and the current trends of its application are introduced.

• 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.