Ultrasonic Dispersion (AV/V) Determined from Mechanical Resonance Frequency Shifts

This paper proposes a novel structural damage quantification approach using a sparse regularization based electromechanical impedance (EMI) technique. Minor structural damage in plate structures by using the measurement of only a single surface bonded lead zirconate titanate piezoelectric (PZT) transducer was quantified. To overcome the limitations of using model-based EMI based methods in damage detection of complex or relatively large-scale structures, a three-dimensional finite element model for simulating the PZT–structure interaction is developed and calibrated with experimental results. Based on the sensitivities of the resonance frequency shifts of the impedance responses with respect to the physical parameters of plate structures, sparse regularization was applied to conduct the undetermined inverse identification of structural damage. The difference between the measured and analytically obtained impedance responses was calculated and used for identification. In this study, only a limited number of the resonance frequency shifts were obtained from the selected frequency range for damage identification of plate structures with numerous elements. The results demonstrate a better performance than those from the conventional Tikhonov regularization based methods in conducting inverse identification for damage quantification. Experimental studies on an aluminum plate were conducted to investigate the effectiveness and accuracy of the proposed approach. To test the robustness of the proposed approach, the identification results of a plate structure under varying temperature conditions are also presented.

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A new method to determine the mechanical resonance frequency, quality factor and charging in electrostatically actuated MEMS

2008 IEEE 21st International Conference on Micro Electro Mechanical Systems ◽

10.1109/memsys.2008.4443741 ◽

2008 ◽

Cited By ~ 4

Author(s):

S. Kalicinski ◽

H.A.C. Tilmans ◽

M. Wevers ◽

I. De Wolf

Keyword(s):

Resonance Frequency ◽

Quality Factor ◽

New Method ◽

Mechanical Resonance ◽

Electrostatically Actuated

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Dipolar resonance frequency shifts in1H MR spectra of skeletal muscle: Confirmation in rats at 4.7 Tin Vivo and observation of changes postmortem

Magnetic Resonance in Medicine ◽

10.1002/mrm.1910380107 ◽

1997 ◽

Vol 38 (1) ◽

pp. 33-39 ◽

Cited By ~ 30

Author(s):

Vasilis Ntziachristos ◽

Roland Kreis ◽

Chris Boesch ◽

Bjørn Quistorff

Keyword(s):

Skeletal Muscle ◽

Resonance Frequency ◽

Frequency Shifts

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Control Algorithm Study for some Optical Tracking Measurement System with Low Mechanical Resonance Frequency

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.188.241 ◽

2011 ◽

Vol 188 ◽

pp. 241-245

Author(s):

Yong Li Bi ◽

Zhong Xian Wang

Keyword(s):

Linear System ◽

Resonance Frequency ◽

Control Algorithm ◽

Fuzzy Controller ◽

Controller Design ◽

Optical Tracking ◽

Mechanical Resonance ◽

Non Linear ◽

Non Linear System ◽

Tracking Measurement

For some optical tracking measurement systems, because their size, weight and space structure are very strict restrictions, DC servo motors have to drive the loads through the several stages of gear transmission. For such a nonlinear controlled object, it is difficult to obtain acceptable control performance applying the traditional controller design method. In the paper, firstly, establish such a non-linear system dynamic model, and consider intelligent control algorithm to inhibit mechanical resonance effect for the control system performance. In order to achieve real-time control easily, the paper suggests a fuzzy numeric model with the self-regulating factor based on analytic expression for such a non-linear system. The result demonstrates that the fuzzy controller is very effective in applications. This work provides a new thought for a controller design to inhibit the low mechanical resonance frequency.

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