• 한국소음진동공학회논문집
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• 제13권3호
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• pp.155-163
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• 2003

This paper presents the characteristics of the radial nitration of cylindrical piezoelectric transducers. The differential equations of piezoelectric radial motion have been derived in terms of the radial displacement and electric potential, which are functions of the radial and axial coordinates. Applying mechanical and electrical boundary conditions has yielded the characteristic equation of radial vibration. Numerical results of the natural frequencies have been compared with the experimental observations reported earlier for the transducers of several sizes, and have shown a good agreement for the fundamental mode. The paper discusses the dependence of the natural frequencies on the radius and thickness of the piezoelectric cylinders and the difference between Piezoelectric and elastic resonances.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.1202-1209
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• 2002

This paper presents the characteristics of the radial vibration of cylindrical piezoelectric transducers. The differential equations of piezoelectric radial motion have been derived in terms of the radial displacement and electric potential, which are functions of the radial and axial coordinates. Applying mechanical and electrical boundary conditions has yielded the characteristic equation of radial vibration. Numerical results of the natural frequencies have been compared with the experimental observations reported earlier for the transducers of several sizes, and have shown a good agreement for the fundamental mode. The paper discusses the dependence of the natural frequencies on the radius and thickness of the piezoelectric cylinders and the difference between Piezoelectric and elastic resonances

• 한국소음진동공학회논문집
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• 제26권7호
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• pp.881-887
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• 2016

In this study, the vibration-based tactile actuator for smart wear applications is presented by using piezoelectric ceramic transducers. The compact wireless actuation system is constructed with a high voltage piezoelectric amplifier, a microcontroller, wireless communication module, and rechargeable lithium-polymer battery. For the wireless communication between a hardware and an operator, the bluetooth-based wireless communication system is prepared and the user interface is provided via smart phone applications. From a series of experimental user studies, it is demonstrated that the proposed vibro-tactile actuator based on piezoelectric ceramic transducers can be effectively applied to smart wear applications.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1280-1285
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• 2000

The paper deals with a theoretical study on the vibrational characteristics of piezoelectric torsional transducers. The differential equations of piezoelectric torsional motion have been derived in terms of the circumferential displacement and the electric potential. Applying mechanical and electrical boundary conditions has yielded the characteristic equations of natural vibration in several transducer types. Numerical results have clarified the effect of the piezoelectric phenomenon on the mechanical resonance and the effect of the elastic block of a Langevin-type transducer on the natural frequency.

• 소음진동
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• 제10권6호
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• pp.955-962
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• 2000

The paper deals with a theoretical study on the vibrational characteristics of piezoelectric torsional transducers. The differential equations of piezoelectric torsional motion have been derived in terms of the circumferential displacement and the electric potential. Applying mechanical and electrical boundary conditions has yielded the characteristic equations of natural vibration in several transducer types. Numerical results have clarified the effect of the piezoelectric phenomenon on the mechanical resonance and the effect of the elastic block of a Langevin-type transducer on the natural frequency.

• Smart Structures and Systems
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• 제11권2호
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• pp.185-197
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• 2013

We developed a simultaneous strain measurement and damage detection technique using a pair of surface-mounted piezoelectric transducers and a fiber connecting them. This is a novel sensor configuration of the fiber acoustic wave (FAW) piezoelectric transducer. In this study, lead-zirconate-titanate (PZT) transducers are installed conventionally on a plate's surface, which is a technique used in many structural health monitoring studies. However, our PZTs are also connected with an optical fiber. A FAW and Lamb wave are simultaneously guided in the optical fiber and the structure, respectively. The dependency of the time-of-flight of the FAW on the applied strain is quantified for strain sensing. In our experimental results, the FAW exhibited excellent linear behavior and no hysteresis with respect to the change in strain. On the other hand, the well-known damage detection function of the surface-mounted PZT transducers was still available by monitoring the waveform change in the conventional Lamb wave ultrasonic path.

• 비파괴검사학회지
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• 제21권4호
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• pp.434-438
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• 2001

봉에서 전파하는 비틀림파를 발생시키는 압전 비틀림 파동 변환기를 제작하였다. 비틀림 파동을 발생시키는 원리는 원주방향으로 분극된 압전 원판에 인가된 두께 방향 전압에 의해 나타나는 원주방향 전단운동이다. 압전 비틀림 원판을 제작한 후, 공진 주파수를 낮추기 위하여 랑주방(Langevin)형 비틀림 변환기를 제작하였다. 제작된 변환기들의 공진 주파수를 측정한 결과, 해석에 의해 예상된 특성과 잘 일치하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1403-1405
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• 1994

In this study, the piezoelectric transducers with 1-3 connectivity have maded. A piezoelectric ceramic PZT prepared by Wet-Dry Combination method is used as a filler in Eccogel polymer matrix. The pulse-echo response for 1-3 type composite transducers were carried out in water. It was observed that the transmitting and receiving sensitivity of 1-3 type composite transducers were improved in comparison with that or solid PZT transducer. The reason is for that 1-3 composites have a hish piezoelectric voltage coefficients, The period of pulse-echo response for the transducer is in a good agreement with the resonant frequency of self-maded composite transducer.

• 비파괴검사학회지
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• 제32권5호
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• pp.585-596
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• 2012

PVDF와 P(VDF-TrFE)로 대별되는 압전고분자는 종래의 대표적인 압전재료인 PZT에 비해 전기음향변환효율이 떨어지며 내부손실이 큰 단점은 있으나, 음향임피던스가 물 또는 생체와 비슷하고 수신효율이 우수하며 광대역 특성을 나타내는 등의 장점을 가진 재료이다. 또한 다른 압전재료에 비해 얇은 막으로의 제작이 쉽고, 그 막은 유연하므로 복잡한 곡면을 갖는 고주파 초음파 트랜스듀서 재료로 유용하다. 그러한 특성은 생의학적 응용에 적합한바, 다양한 형태의 초음파 트랜스듀서가 연구 개발되어져 왔다. 본 논문에서는 먼저, 압전고분자막을 이용하여 초음파 트랜스듀서를 설계 제작하는데 있어서 고려해야할 몇 가지 주요사항을 기술하고, KLM 모델을 사용한 해석을 통하여 그 고려사항들이 트랜스듀서의 동작에 미치는 영향을 파악하였다. 다음으로, 의학적 또는 생물학적 응용을 목적으로 초음파 영상을 얻고 있는 몇몇 주요 응용분야에서 사용되는 압전고분자 트랜스듀서의 구조와 그것을 이용하여 얻은 영상의 특징에 대하여 간략히 해설하였다.

• Smart Structures and Systems
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• 제15권4호
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• pp.1063-1083
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• 2015

The main purpose of this research is to utilize simple mathematical models to depict the vibration behavior and the resulted sound field of a piezoelectric disk for ultrasonic transducers. Instead of using 1-D vibration model, coupled effect between the thickness and the radial motions was considered to be close to the real vibration behavior. Moreover, Huygens-Fresnel principle was used in both incident and reflected waves to analyze the sound field under obstacles in finite distance. Results of the tested piezoelectric disk show that, discrepancies between the simulation and experiment are 2.5% for resonant frequency and 12% for resulted sound field. Therefore, the proposed method can be used to reduce the complexity in modeling vibration problems, and increase the reliability on analyzing piezoeletric transducers in the design stage.