• Title/Summary/Keyword: Superharmonic Resonance

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Nonlinear Vibrations of Piezoelectric Microactuators in Hard Disk Drives (하드디스크 드라이브용 압전형 마이크로 액추에이터의 비선형 진동 특성)

  • Jeong, Deok-Yeong;Lee, Seung-Yeop;Kim, Cheol-Sun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.12
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    • pp.2002-2008
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    • 2001
  • Nonlinear vibration characteristics of a piezoelectric-type micro actuator used for hard disk drives are experimentally studied. The nonlinear characterisitics include hysteresis, superharmonic resonance, jump phenomenon, and shifting of natural frequencies. The vibration modes and frequencies of the commercial actuator of the Hutchinson's Magnum series are measured using a laser vibrometer. From harmonic excitation to the PZT acturator, we observe interesting hysteresis patterns with 3 times input frequency. It is shown that the micro actuator has the typical 3 times superhamonic resonances coupled to the first torsional and sway modes of the suspension.

Secondary resonances of a microresonator under AC-DC electrostatic and DC piezoelectric actuations

  • Zamanian, M.;Hosseini, S.A.A.
    • Structural Engineering and Mechanics
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    • v.42 no.5
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    • pp.677-699
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    • 2012
  • This article studies the secondary resonances of a clamped-clamped microresonator under combined electrostatic and piezoelectric actuations. The electrostatic actuation is induced by applying the AC-DC voltage between the microbeam and the electrode plate that lies at the opposite side of the microbeam. The piezoelectric actuation is induced by applying the DC voltage between upper and lower sides of piezoelectric layer. It is assumed that the neutral axis of bending is stretched when the microbeam is deflected. The drift effect of piezoelectric layer (the phenomenon where there is a slow increase of the free strain after the application of a DC field) is neglected. The equations of motion are solved by using the multiple scale perturbation method. The system possesses a subharmonic resonance of order one-half and a superharmonic resonance of order two. It is shown that using the DC piezoelectric actuation, the sensitivity of AC-DC electrostatically actuated microresonator under subharmonic and superharmonic resonances may be tuned. In addition, it is shown that the tuning domain of the microbeam under combined electrostatic and piezoelectric actuations at subharmonic and superharmonic conditions is larger than the tuning domain of microbeam under only the electrostatic actuation.

Nonlinear Vibration Characteristics of Piezoelectric Microactuators in Hard Disk Drive Drives (HDD용 압전형 마이크로 액츄에이터의 비선형 진동특성)

  • Chong, Duk-Young;Lee, Seung-Yop;Kim, Chul-Soon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.225-231
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    • 2000
  • Nonlinear characteristics of piezoelectric-type micro actuator used for hard disk drives are experimentally analyzed using Hutchinson's Magnum acturator. The nonlinear effects include hysteresis, superharmonic resonance, jump phenomenon, and shifting of natural frequencies. The effects of exciting frequency and input voltage on the nonlinear phenomena are investigated. It is shown that the micro actuator has the typical 3 times superhamonic resonances coupled to both 1st torsional and sway modes of the suspension.

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Nonlinear Dynamic Response of Cantilevered Carbon Nanotube Resonator by Electrostatic Excitation (정전기력 가진에 의한 외팔보형 탄소나노튜브 공진기의 비선형 동적 응답)

  • Kim, Il-Kwang;Lee, Soo-Il
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.9
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    • pp.813-819
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    • 2011
  • This paper predicted nonlinear dynamic responses of a cantilevered carbon nanotube(CNT) resonator incorporating the electrostatic forces and van der Waals interactions between the CNT cantilever and ground plane. The structural model of CNT includes geometric and inertial nonlinearities to investigate various phenomena of nonlinear responses of the CNT due to the electrostatic excitation. In order to solve this problem, we used Galerkin's approximation and the numerical integration techniques. As a result, the CNT nano-resonator shows the softening effect through saddle-node bifurcation near primary resonance frequency with increasing the applied AC and DC voltages. Also we can predict nonlinear secondary resonances such as superharmonic and subharmonic resonances. The superharmonic resonance of the nano-resonator is influenced by applied AC voltage. The period-doubling bifurcation leads to the subharmonic resonance which occurs when the nano-resonator is actuated by electrostatic forces as parametric excitation.