Two-dimensional optical coherence vibration tomography for low-frequency vibration measurement and response-only modal analysis

2016 ◽  
Vol 79 ◽  
pp. 65-71 ◽  
Author(s):  
Jianfeng Zhong ◽  
Shuncong Zhong ◽  
Qiukun Zhang
Keyword(s):  
Modal Analysis ◽  
Low Frequency ◽  
Vibration Measurement ◽  
Optical Coherence ◽  
Two Dimensional ◽  
Low Frequency Vibration

Origami-Based Bistable Metastructures for Low-Frequency Vibration Control

2021 ◽  
Vol 88 (5) ◽  
Author(s):  
Mingkai Zhang ◽  
Jinkyu Yang ◽  
Rui Zhu
Keyword(s):  
Vibration Isolation ◽  
Energy Analysis ◽  
Geometrical Nonlinearity ◽  
Low Frequency ◽  
Quantitative Relationship ◽  
Vibration Modes ◽  
Two Dimensional ◽  
Low Frequency Vibration ◽  
Dynamic Experiments ◽  
Unit Cells

Abstract In this research, we aim to combine origami units with vibration-filtering metastructures. By employing the bistable origami structure as resonant unit cells, we propose metastructures with low-frequency vibration isolation ability. The geometrical nonlinearity of the origami building block is harnessed for the adjustable stiffness of the metastructure’s resonant unit. The quantitative relationship between the overall stiffness and geometric parameter of the origami unit is revealed through the potential energy analysis. Both static and dynamic experiments are conducted on the bistable origami cell and the constructed beam-like metastructure to verify the adjustable stiffness and the tunable vibration isolation zone, respectively. Finally, a two-dimensional (2D) plate-like metastructure is designed and numerically studied for the control of different vibration modes. The proposed origami-based metastructures can be potentially useful in various engineering applications where structures with vibration isolation abilities are appreciated.

Low-Frequency Vibration Measurement Based on Spatiotemporal Analysis of Shadow Moiré

2011 ◽  
Vol 31 (4) ◽  
pp. 0412005
Author(s):  
史红健 Shi Hongjian ◽  
朱飞鹏 Zhu Feipeng ◽  
何小元 He Xiaoyuan
Keyword(s):  
Low Frequency ◽  
Spatiotemporal Analysis ◽  
Vibration Measurement ◽  
Shadow Moire ◽  
Shadow Moiré ◽  
Low Frequency Vibration

scholarly journals Low-frequency vibration measurement by a dual-frequency DBR fiber laser

2017 ◽  
Vol 7 (3) ◽  
pp. 206-210 ◽  
Author(s):  
Bing Zhang ◽  
Linghao Cheng ◽  
Yizhi Liang ◽  
Long Jin ◽  
Tuan Guo ◽  
...  
Keyword(s):  
Fiber Laser ◽  
Low Frequency ◽  
Vibration Measurement ◽  
Dual Frequency ◽  
Low Frequency Vibration

Polishing Characteristics of a Low Frequency Vibration Assisted Polishing Method

2013 ◽  
Vol 797 ◽  
pp. 450-454 ◽  
Author(s):  
Wei Min Lin ◽  
Sze Keat Chee ◽  
Hirofumi Suzuki ◽  
Toshiro Higuchi
Keyword(s):  
Surface Roughness ◽  
Piezoelectric Actuator ◽  
Medical Devices ◽  
Material Removal ◽  
Low Frequency ◽  
Experimental Results ◽  
Two Dimensional ◽  
Digital Devices ◽  
Low Frequency Vibration

Demands of precision molds with complicated microstructures for digital devices such as DVD pick-up system, and medical devices such as μ-TAS and solar optics etc. are increasing. To enhance precision, the structured molds must be polished after grinding or cutting in order to improve the surface roughness. In this paper, a two-dimensional low frequency vibration (LFV) polishing actuator using PZT is proposed and developed. The LFV consists of four mechanical amplitude magnified actuators, a multilayer stacked piezoelectric actuator (PZT) incorporated with mechanical transformer, and a center piece. In the polishing experiments, HIPM workpieces were polished with WA slurry by the rotation & revolution type polishing method (RRP). The surface roughness of the work pieces and material removal amount (polished amount) was also evaluated. From the experimental results, it was found that the application of low frequency vibration is useful for realizing higher precision in the polishing of micro structured molds.

scholarly journals Modal analysis and demonstration of metastructure combining local resonators and an autonomous synchronized switch damping circuit

2022 ◽  
pp. 146134842110682
Author(s):  
Haruhiko Asanuma ◽  
Sumito Yamauchi
Keyword(s):  
Modal Analysis ◽  
Low Frequency ◽  
Coupled Analysis ◽  
Resonant Vibration ◽  
Power Sources ◽  
Low Frequency Vibration ◽  
Vibration Attenuation ◽  
Signal Processors ◽  
Coupled Equation ◽  
Frequency Axis

A locally resonant metastructure is a promising approach for low-frequency vibration attenuation, whereas the attachment of many resonators results in unnecessary and multiple resonance outside the bandgap. To address this issue, we propose a damping metastructure combining local resonators and an autonomous synchronized switch damping circuit. On the basis of modal analysis, we derive an electromechanically coupled equation of the proposed metastructure. The piezo ceramics, which are attached on a small portion of the metastructure and connected to the circuit, remarkably decrease the magnitude of the resonant vibration with no extra sensors, signal processors, or power sources. The displacement at unnecessary resonance was decreased by approximately 75%. The results of the coupled analysis were similar to the experimentally observed results in terms of the location and width of the bandgap on the frequency axis and the decreased displacement for the circuit. The proposed technique can overcome the disadvantage of the metastructure.

Acoustic-Excitation Optical Coherence Vibrometer for Real-Time Microstructure Vibration Measurement and Modal Analysis

2020 ◽  
Vol 69 (9) ◽  
pp. 7209-7217
Author(s):  
Ning Zhou ◽  
Shuncong Zhong ◽  
Jiewen Lin ◽  
Manting Luo ◽  
Walter Nsengiyumva ◽  
...  
Keyword(s):  
Modal Analysis ◽  
Real Time ◽  
Vibration Measurement ◽  
Acoustic Excitation ◽  
Optical Coherence

Precision Polishing of Micro Mold by Using Piezoelectric Actuator Incorporated with Mechanical Amplitude Magnified Mechanism

2011 ◽  
Vol 325 ◽  
pp. 470-475 ◽  
Author(s):  
Sze Keat Chee ◽  
Hirofumi Suzuki ◽  
Mutsumi Okada ◽  
Takeshi Yano ◽  
Toshiro Higuchi ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tungsten Carbide ◽  
Piezoelectric Actuator ◽  
Medical Devices ◽  
Low Frequency ◽  
Two Dimensional ◽  
Digital Devices ◽  
Flexure Hinges ◽  
Low Frequency Vibration ◽  
Polishing Efficiency

Demands of precision molds with complicated microstructures for digital devices such as DVD pick-up system, medical devices such as μ-TAS and solar optics etc. are increasing [1 - 5]. The structured molds must be polished after grinding or cutting in order to improve the surface roughness. In this paper, a two dimensional low frequency vibration (2DLFV) polishing actuator using PZT is proposed and developed. The 2DLFV consists of 4 mechanical amplitude magnified actuators (MechaTrans), a multilayer stacked piezoelectric actuator (PZT) incorporated with mechanical transformer, and a center piece. Mechanical transformer is a kind of flexure hinges structured that magnifies the stroke of the multilayer stacked piezoelectric actuator around 7 times to 120 μm. With this actuation, the tool vibrates in a circle trajectory to achieve polishing effect. In the polishing experiments, tungsten carbide molds (workpieces) are polished with diamond slurry. The surface roughness of the work pieces and polishing efficiency are evaluated. From the experimental results, it was found that low frequency vibration especially 2DLFV is a useful polishing system for micro structured mold.

scholarly journals Two-dimensional low-frequency vibration attenuator using X pendulums

1999 ◽  
Vol 70 (2) ◽  
pp. 1561-1564 ◽  
Author(s):  
D. Tatsumi ◽  
Mark A. Barton ◽  
T. Uchiyama ◽  
K. Kuroda
Keyword(s):  
Low Frequency ◽  
Two Dimensional ◽  
Low Frequency Vibration
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