Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 21 for “"laser vibrometer"”.
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Digital frequency demodulation for a laser vibrometer
… to a Michelson interferometer-based scanning laser vibrometer. The laser vibrometer is a velocity transducer that produces frequency-modulated signals that have traditionally been optically or electronically frequency shifted from baseband to an intermediate frequency. This shifting produces a …
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A Formulation for Updating Finite Element Models Through Consistent Use of Laser Vibrometer Data
… finite element(FE) models using scanning laser Doppler vibrometer(SLDV) dynamic response data. The update formulation is demonstrated in several computer simulations. The formulation is the result of incorporating an analytical FE model into an experimental model. The experimental model …
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Vibrations of high-speed dental handpieces measured using laser vibrometry
… loaded conditions using a non-contact Scanning Laser Vibrometer (SLV). Methods: Five turbines (two KaVo, three W&H) and two speed-increasing handpieces (one KaVo and one W&H) were investigated using a Polytec SLV (PSV-300). Handpieces were operated under various conditions which included …
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Detection of defects in FRP-reinforced concrete with the acoustic-laser vibrometry method
… A novel approach called the acoustic-laser vibrometry method which is capable of remote assessment of damage in FRP-reinforced concrete, is investigated in this thesis. It exploits the fact that areas where the FRP has debonded from concrete will vibrate excessively compared to intact …
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Radial-turbine mistuning
… believed to contribute to this failure mode. A laser vibrometer is used to characterize mistuning for a population of turbine wheels through the analysis of the blade-response to piezo-speaker induced noise. The turbine-wheel design under investigation is radial and is typically used in 6-12L …
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Active structural acoustic control smart panel with small scale proof mass actuators
… the spatially averaged vibration measured with a laser vibrometer and the reduction of the total sound power radiation measured in an anechoic room are presented.
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Vibration Extraction Using Rolling Shutter Cameras
… need either direct contact with the object or a laser vibrometer. Although computer vision methods have been applied to solve this problem, high speed cameras are usually preferred. This study employs a consumer level rolling shutter camera for extracting main frequency components of small …
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Remote nondestructive evaluation of composite-steel interface by acoustic laser vibrometry
… form of nondestructive testing (NDT). Acoustic laser vibrometry is a relatively new method of NDT that shows a lot of promise in analysis of this interface. In this approach, an airborne acoustic wave is utilized to excite the location of the damage underneath the FRP sheets/plates and the …
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Operational Modal Analysis of Rolling Tire: A Tire Cavity Accelerometer Mediated Approach
… operating conditions. The present start-of-art laser vibrometer based non-contact measurements are limited to tread vibration measurement of smooth tires only in a lab environment. This study focuses on devising an innovative strategy to use a wireless Tire Cavity Accelerometer (TCA) and two …
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Development Of Silicon-Based Anodes And In-Situ Characterization Techniques For Lithium Ion Batteries
… a white light interferometry (WLI) and laser vibrometer were used to gather quantitative data. Amorphous silicon (<i>a</i>-Si) was explored for the stress measurement.</p>
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Damage detection methodology for composite UAV wings using modal analysis and probabilistic concepts
… wing was subsequently improved using a scanning laser vibrometer to conduct detailed experimental modal analyses of five wings, and a multi-model updating approach based on frequency and mode shape information was used to update selected sensitive material properties. Significant improvement was …
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Application of distributed measurements for finite element model verification
The wealth of experimental laser data and its high accuracy allow a rigorous comparison between a distributed model and distributed measurements that was not possible previously. The purpose of this work is to obtain and compare experimental and analytical distributed measurements for a simple …
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Novel Bio-inspired Aquatic Flow Sensors
… synchronized motion tracking of the hair with a laser vibrometer and current measurements across the artificial cell membrane.
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Construction of frequency-energy plots for nonlinear dynamical systems from time-series data
… obtained either by direct measurement, using a laser vibrometer or equivalent; or through time differentiation or integration of measured displacement or acceleration, respectively. The FEP is generated through three intermediate steps. First, the total energy of the system is estimated by …
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An investigation of cochlear dynamics in surgical and implanation processes
… and is measured using a Micro- Scanning Laser Vibrometer operating through a microscope. There are two principal outcomes of the research: First, the approach has enabled disturbances in the cochlea to be contrasted for different surgical techniques, which it is expected to allude …
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Vibrating lubricant-infused porous surface for enhanced liquid droplet transport
… mode shapes of SLIPS membrane studied by laser vibrometer, and (ii) oscillatory droplet contact line dynamics studied by high-speed photography. Finally, we further demonstrate how vibrational actuation into SLIPS achieves enhanced condensate repellency and heat transfer compared to …
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Examination of the application and limitations of structural mode extraction via force apportionment
… examining the structural response as measured by laser vibrometry. First, the structure is investigated using impact-test-based modal extraction methods. Approximate mode shapes are determined by examining the phase resonance indicator function for the resonance responses at a number of reference …
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Non-contact quantitative imaging of limbs, bone and tissue, using ultrasound tomographic techniques
… The first imaging system is based on laser generation and detection of ultrasound (LUS) and the second is a water immersion ultrasound tomography (UST) system. The LUS and UST systems and algorithms, in aggregate, can be used to generate large volume, quantitative 2D and traditional 2D …
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Vibration and Buckling Analysis of Unitized Structure Using Meshfree Method and Kriging Model
… clamping bracket using acoustic excitation and a laser vibrometer. Experimental results appear to correlate well with the meshfree and Ritz method results. In reality, many engineering structures are subjected to random pressure loads in nature and cannot be assumed to be deterministic. Typical …
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Mechanical Properties of Candidate Materials for Morphing Wings
… supply a pressure load to the material, while a laser vibrometer measured how much the material deflected. A regulator was used to control the amount of pressure that was applied to the material. As the pressure load was increased, the material deflected more. The test stand also determined the …
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