• 제목/요약/키워드: Piezoelectric Materials

검색결과 930건 처리시간 0.032초

압전 재료를 이용한 전기 차단기의 능동제진 (Active Damping of an Electric Connector with Piezoelectric Materials)

  • 노용래
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1992년도 추계학술대회논문집; 반도아카데미, 20 Nov. 1992
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    • pp.92-97
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    • 1992
  • Undesired vibratory motion of an electric connector is controlled in an active method with piezoelectric sensors and actuators. A special electric control box is developed which is suitable for the purpose. Experimental results show that the system can effectively reduce amplitude responses connector to external forces.

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Mode III fracture analysis of piezoelectric materials by Trefftz BEM

  • Qin, Qing-Hua
    • Structural Engineering and Mechanics
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    • 제20권2호
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    • pp.225-239
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    • 2005
  • Applications of the Trefftz boundary element method (BEM) to anti-plane electroelastic problems are presented in this paper. Both direct and indirect methods with domain decomposition are discussed in details. Each crack is treated as semi-infinite thin slit defined in a subregion, for which a particular solution of the anti-plane problem, satisfying exactly the crack-face condition, is derived. The stress intensity factors defined at each crack tip can be directly computed from the coefficients of the particular solution. The performance of the proposed formulation is assessed by two examples and comparison is made with results obtained by other approaches. The Trefftz boundary element approach is demonstrated to be suitable for the analysis of the anti-plane problem of piezoelectric materials.

원통 봉을 적용한 압전 캔틸레버의 성능 향상 (Improved Power Output by a Piezoelectric Cantilever after Addition of a Cylindrical Bar)

  • 이영진;김세기;김영득
    • 한국세라믹학회지
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    • 제51권5호
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    • pp.516-521
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    • 2014
  • This paper describes the development of a new piezoelectric unimorph cantilever structure intended to improve electrical output power, compared to a conventional cantilever. The proposed structure employs a cylindrical bar attached to one side of a steel plate, which is a significant factor in forced vibration mode. The feasibility of the proposed methodology was assessed experimentally and theoretically. The influence of three different types of bar material (i.e., stainless steel, silicon rubber, and urethane), and bar position, on the output voltage were examined and compared with those without the bar. The optimal position and material for the bar were identified through experimental and theoretical analyses. It appears that the electrical output power of the proposed cantilever is about 40% higher than that of a conventional unimorph cantilever.

압전필름센서를 이용한 복합재 평판의 저속충격 손상개시 모니터링 (Monitoring of Low-velocity Impact Damage Initiation of Gr/Ep Panel Using Piezoelectric Thin Film sensor)

  • 이관호;박찬익;김인걸;이영신
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2001년도 추계학술발표대회 논문집
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    • pp.174-178
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    • 2001
  • The piezoelectric thin film sensor can be used to interpret variations in structural and material properties, e.g. for structural integrity monitoring and assessment. To illustrate one of this potential benefit, PVDF film sensors are used for monitoring impact damage initiation in Gr/Ep composite panel. Both PVDF film sensors and strain gages are surface mounted to the Gr/Ep specimens. A series of impact test at various impact energy by changing impact mass and height is performed on the instrumented drop weight impact tester. The sensor responses are carefully examined to predict the onset of impact damage such as matrix cracking, delamination, and fiber breakage, etc. Test results show that the particular waveforms of sensor signals implying the damage initiation and development are detected above the damage initiation impact energy. As expected, the PVDF film sensor is found to be more sensitive to impact damage initiation event than the strain gage.

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열-전기-기계 하중을 받는 스마트 복합재 평판의 고차 지그재그 유한요소의 개발 및 성능 평가 (Development and Assessment of Higher Order Zig-zag Theory for smart composite plates under mechanical, thermal, and electric loads)

  • 오진호;조맹효
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2001년도 추계학술발표대회 논문집
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    • pp.191-194
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    • 2001
  • A partially coupled thermo-piezoelectric-mechanical triangular finite element model of composite laminates with surface bonded piezoelectric actuators, subjected to externally applied mechanical load, temperature change load, electric field load is developed. The governing differential equations are obtained by applying the principle of free energy and variational techniques. A higher order zigzag theory displacement field is employed to accurately capture the transverse shear and normal effects in laminated composite plates of arbitrary thickness. Nonconforming shape functions by Specht are employed in the transverse displacement variables. Numerical examples demonstrate the accuracy and efficiency of the proposed triangular plate element.

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탄성체에 접합된 압전 스트립에서의 균열 전파 거동 (Steady State Crack Propagation Behavior in a Piezoelectric Strip Bonded to Elastic Materials)

  • 권순만;최효승;이강용
    • 대한기계학회논문집A
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    • 제26권2호
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    • pp.283-290
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    • 2002
  • In this paper, we consider the dynamic electromechanical behavior of an eccentric Yoffe permeable crack in a piezoelectric ceramic strip sandwiched between two elastic orthotropic materials under the combined anti-plane mechanical shear and in-plane electrical loadings. Fourier transforms are used to reduce the problem to the solution of two pairs of dual integral equations, which are then expressed to a Fredholm integral equation of the second kind. The initial crack propagation orientation for PZT-5H piezoceramics is predicted by maximum energy release rate criterion.

단결정 압전작동기를 사용한 능동 뒷전플랩 블레이드의 진동하중 감소해석 (Vibratory Loads Reduction Analysis of Active Trailing-edge Flap Blades Using Single Crystal Piezoelectric Actuators)

  • 박재상;김태성;신상준
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 추계학술대회논문집
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    • pp.326-331
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    • 2007
  • This paper conducts a vibratory loads reduction analysis of an Advanced Active Trailing-edge Flap (AATF) blade utilizing single crystal piezoelectric actuators. For an AATF blade, a new L-L piezostack actuator using single crystal PMN-PT materials is designed. The AATF blade is designed to have similar characteristics to the Advanced Active Twist Rotor (AATR) blade. The active trailingedge flap is assumed to be 20% of the blade span and 15% of the chord, located at 75% of the blade radius. In order to conduct the vibratory loads reduction analysis of the AATF blade in forward flight, DYMORE, a multi-body dynamics analysis code, is used. The simulation result shows that the hub vibratory loads may be reduced by approximately 89% even with a much lower input-voltage when comparing with the other active rotor systems.

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압전작동기로 구동되는 원통형 Parts Feeder의 모드 해석 (Modal Analysis of Bowl Parts Feeder Activated by Piezoactuators)

  • 최승복;이동호;김재환;정재천
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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    • pp.432-437
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    • 1998
  • This paper presents modal characteristics of bowl parts feeder featuring piezoelectric actuators. As wellknown, the piezoelectric materials develop an electric charge proportional to a mechanical stress and vice versa. This generic phenomenon allows us to use the piezoelectric materials as sensors and actuators. Using the actuating property, we can device effective bowl parts feeder. The parts feeder activated by the piezoceramic actuators provides a large degree of freedom of controlling excitation magnitude and frequency, and thus accurate and fast feeding of various parts. As a first phase to demonstrate these advantages, a finite clement model of the bowl parts feeder is constructed and analyzed using commercial software packages. In addition, the simulated modal characteristics are compared with the measured ones to validate the proposed model.

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