• Title/Summary/Keyword: piezoceramic

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Hybrid Vibration Control of Smart Laminated Composite Beams using Piezoelectric and Viscoelastic Material (압전재료와 점탄성 재료를 이용한 지능 복합적층보의 하이 브리드 진동제어)

  • Kang, Young-Kyu
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.10
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    • pp.148-153
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    • 2001
  • Active control of flexural vibrations of smart laminated composite beams has been carried out using piezoceramic sensor/actuator and viscoelastic material. The beams with passive constrained layer damping hale been analyzed by formulating the equations of motion through the use of extended Hamilton's principle. The dynamic characteristics such as damping ratio and modal damping of the beam are calculated for various fiber orientations by means of iterative complex eigensolution method. This paper addresses a design strategy of laminated composite under flexural vibrations to design structure with maximum possible damping capacity.

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Vibration Reduction of Optical Storage Disk Drive Using Piezoelectric Shunt (압전 션트회로를 이용한 광저장 디스크 드라이브의 진동 저감)

  • 박종성;임수철;최승복;김재환;박영필
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.381-386
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    • 2002
  • This paper presents a piezoelectric shunt methodology to reduce unwanted vibration of optical disk drive(O.D.D.). After briefly investigating a second-order mechanical vibration absorber model, the O.D.D. structure is incorporated with the piezoelectric shunt circuit. In order to evaluate feasibility of multi-mode passive damping of the structure, admittance measurement of piezoceramic is undertaken. The parameters are optimally tuned by admittance measurement results on the basis of the circuit model and displacement transmissibility is evaluated. To verify validity of admittance measurement result, experiment is performed and vibration reduction is achieved at two different modes.

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Multiple-Mode Vibration Control Using Piezoelectric Shunted Actuator (압전 분기회로를 이용한 다중모드제어)

  • 박철휴
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.202-207
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    • 2002
  • This paper deals with a novel shunted actuator, which has a capability to suppress multi-mode vibration amplitudes by using a pair of piezoceramic patches. In order to describe the characteristic behaviors of shunted dampers connected with a series and a parallel resistor-negative capacitive branch circuit, the stiffness ratio and loss factor with respect to the non-dimensional frequency are considered. To obtain a guideline model of a piezo/beam system connected with a series and a parallel resistor-negative capacitor branch circuit, the governing equations of motion is derived through Hamiltons principle and a piezo sensor equation as well as a shunt damping matrix is developed. The theoretical analysis shows that the shunted actuator developed in this study can significantly reduce multiple-mode vibration amplitudes simultaneously over the whole structural frequency range.

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Vibration Suppression of Smart Structures Using PPF and SRF Control Techniques (PPF와 SRF 제어기법을 사용한 지능구조물의 능동진동제어)

  • 라완규;곽문규;윤광준
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.04a
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    • pp.400-406
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    • 1997
  • This paper is concerned with the active vibration control of grid structure by means of piezoceramic actuators and sensors. The control technique used in this paper is based on the positive position feedback(PPF) and the strain rate feedback(SRF) control, which have been successfully used for the vibration control of beam structures. A new control methodology is developed using the PPF and SRF controller of single-input single-output method. The PPF controller is used for the suppression of first bending mode and SRF controller is used for the suppression of higher vibration modes of grid structure. Electric circuits for the realization of control schemes are explained in detail. The control techniques prove its effectiveness by experiments.

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Experiment of a Simple Feed-forward Active Control Method for the Shock Response of a Flexible Beam and Performance Analysis (유연빔의 충격응답에 대한 단순 피드포워드 능동제어 실험 및 성능분석)

  • Pyo, Sang-Ho;Shin, Ki-Hong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.634-639
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    • 2006
  • Active control method is applied to a flexible beam excited by a shock impulse in order to reduce the residual vibrations after the shock event. It is assumed that the shock input can be measured and is always occurred on the same point of the beam. If the system is well identified and the corresponding inverse system is designed reliably, it has shown that a very simple feed-forward active control method may be applied to suppress the residual vibrations without using error sensors and adaptive algorithm. Both numerical simulations and experimental results show a promising possibility of applying to a practical problem. Also, the performance of the method is examined by considering various practical aspects : shock duration, shock magnitude, and control point.

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Active Control of Multi-Mode Forced Vibration Using PZT (PZT를 이용한 다중 모드 강제 진동의 능동 제어)

  • 한상보;윤신일
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.04a
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    • pp.407-412
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    • 1997
  • There has been a recent surge of research interest on the smart structure. This paper presents active vibration control scheme of multi-mode forced vibration using piezoceramic sensors/actuators. The control scheme adopted is the Positive Position Feedback control. Among various vibration control techniques, PPF control technique makes use of generalized displacement measurements to accomplish vibration suppression. Two independent controllers are implemented to control the first and the second modes of the beam under external excitation. Experimental results for various damping ratio and feedback gains of the PPF controllers are compared with respect to the control efficiency. The results indicate that steady state vibration under wideband excitation can be controlled effectively when multiple sets of PZT sensors/actuators were used with PPF control technique.

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Development of Curved Shape Piezoelectric Unimorph Using Pre-stressed Substrate (초기응력을 가진 기저구조물을 이용한 곡면형 압전 유니모프 개발)

  • Kang, Lae-Hyong;Lee, Jong-Won;Han, Jae-Hung;Chung, Sang-Joon;Ko, Han-Young
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.1
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    • pp.94-100
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    • 2009
  • This paper proposes a novel curved shape piezoelectric unimorph using a new fabrication method. Instead of using thermal coefficient mismatch, which has been used for conventional processes for curved shape unimorphs, we used pre-stressed substrates and the room temperature adhesion process. A difference of the mechanical strains between the substrate and the piezoelectric layer makes the final manufactured unimorph get curved. Several performance tests of the proposed unimorph actuators were accomplished and the test results showed the proposed unimorph actuator got comparable actuation capability compared with conventional curved shape actuators.

Pulse-echo Response of Piezoceramic-Polymer 1-3 Type Composite Transducers (압전 세라믹-고분자 1-3형 복합 압전체 트랜스듀서의 펄스에코 특성)

  • Choi, H.I.;Park, J.H.;Lee, S.H.;SaGong, G.
    • Proceedings of the KIEE Conference
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    • 1994.07b
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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.

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Piezoelectric and Acoustic Properties of PZI-Polymer 1 -3-0 Type Composite (PZT-고분자 1-3-0형 복합압전체의 압전 및 음향특성)

  • 양윤석;유영준;최헌일;손무헌;사공건
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.317-320
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    • 1999
  • In this study, the piezoelectric ceramics PZT powder was synthesized by Wet-Dry combination method. And the flexible 1-3-0 type composites were fabricated with piezoceramic PZT and Eccogel polymer matrix embedded 3rd phase. Dielectric constant of 1-3-0 type composites was lower than that of single phase PZT ceramics. Thickness mode coupling factor k/sub t/ which was comparable with single phase PZT ceramics and mechanical quality factor Qm were about 0.65 and 6, respectively. These composites are considered as a good candidates for broad-band type transducer applications. The acoustic impedance of 1-3-0 type composites was lower than that of single phase PZT ceramics. Therefore, these composites would be better used for hydrophone applications.

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Sensor placement strategy for high quality sensing in machine health monitoring

  • Gao, Robert X.;Wang, Changting;Sheng, Shuangwen
    • Smart Structures and Systems
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    • v.1 no.2
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    • pp.121-140
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    • 2005
  • This paper presents a systematic investigation of the effect of sensor location on the data quality and subsequently, on the effectiveness of machine health monitoring. Based on an analysis of the signal propagation process from the defect location to the sensor, numerical simulations using finite element modeling were conducted on a bearing test bed to determine the signal strength at several representative sensor locations. The results showed that placing sensors closely to the machine component being monitored is critical to achieving high signal-to-noise ratio, thus improving the data quality. Using millimeter-sized piezoceramic plates, the obtained results were evaluated experimentally. A comparison with a set of commercial vibration sensors verified the developed structural dynamics-based sensor placement strategy. It further demonstrated that the proposed shock wave-based sensing technique provided an effective alternative to vibration measurement, while requiring less space for sensor installation.