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 17 of 17 for “"Modal Testing"”.
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Modal testing using high speed digital speckle pattern interferometry
… (SPI) to perform quantified impact modal testing. The interferometer acts as a non-contact multipoint vibrometer that removes the mass-loading effects of contact transducers to improve measurement accuracy and decreases measurement time by the use of multiple measurement points. A …
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Output-Only Experimental Modal Testing of Large Residential Structures and Acoustic Cavities Using Sonic Booms
In this thesis, an output-only experimental modal testing and analysis technique known as the Natural Excitation Technique (NExT) is examined for use with large residential structures and interior cavities. The technique which assumes a random, stationary input causing the response data is reviewed …
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A precision laser scanning system for experimental modal analysis: its test and calibration
… used for dynamic measurements and experimental modal analysis. A laser scanning system that provides position accuracy, speed, and flexibility plays a key role in this technique. This thesis gives an overview of various laser scanning techniques and the requirements of a laser scanning system …
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Optimum Damping of Beam Vibrations Using Piezoceramic Transducers
… realized and finally tested by a standard modal testing technique. Comparisons between different shunting configurations of the system are given and finally the experimental data are compared with ones obtained by the developed numerical code in order to verify the accuracy of the latter.
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Dynamic Testing of In-Situ Composite Floors and Evaluation of Vibration Serviceability Using the Finite Element Method
… areas: best practices in high quality dynamic testing of in-situ floor systems, extensive dynamic testing of three bare (non-fit out) in-situ multi-bay steel composite floors to estimate their dynamic parameters/response and to identify trends in dynamic behavior, and development of a set of …
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A numerical simulation of multiple-shaker model testing
… for the simulation of structural dynamic modal testing by the method of steady-state sinusoidal excitation by discrete shakers. An analytical method commonly known as Asher's Method was employed to optimize the shaker forceamplitude distributions for the purpose of isolating individual …
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Design of an automated on-car brake lathe
… Cutting-tip vibration measurements combined with modal testing showed that chatter was caused by low structural stiffness of the modular bearing rails. A second prototype employing a unitary ground bearing system produced an acceptable surface finish of 70 [mu] -inch at 0.015" depth of cut per …
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Novel Lightweight Noise and Vibration Control Treatments for Marine Structures
This thesis presents the development and testing of distributed vibration absorber designs with specific application to heavy plates for the reduction of vibration and sound radiation. Two particular designs, already under investigation for use on thin panels or composite materials, were adapted to …
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Investigation of a Mobile Damping Robot for Electric Transmission Lines
… through finite element analysis (FEA) and modal testing. We perform numerical analysis in MATLAB using equations of motion obtained via Hamilton's Principle. We discuss the design and validation of an appropriate test bench and MDR prototype. We also experimentally investigate the ability …
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Uncertainty analysis of disc brake squeal propensity
… a finite element model updated by experimental modal testing results. While the deterministic model with a rough lining surface can predict some squeal frequencies identified in noise dynamometer tests, the deterministic model with a smooth lining surface is unable to predict any squeal …
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Analysis, Design, and Experimentation of Beam-Like Structures
… element analysis (FEA). FEA updating based on modal testing and by conducting a geometrically nonlinear analysis resulted in a good agreement against the experiment tests. Furthermore, a nonlinear co-rotational large displacement/rotation FEA including the effects of the pressure as a follower …
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The effects of partitions on the vibration serviceability of concrete floors
… The research project consisted of modal testing on a prestressed pre-tensioned concrete floor slab. The excitation of the floor was generated by an electrodynamic shaker and instrumented impulse hammer. The electrodynamic shaker excitation was used mainly to extract the natural …
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A Novel Framework for Modeling Reconfigurable Dynamic Systems
… to reduce costs and enhance performance. While modal analysis traditionally provides the relationship between dynamic response and frequency, its applicability to reconfigurable systems is limited particulary for high frequency range. To tackle this limitation, this research proposes a novel …
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Structure-thermal coupling in viscoelastic material in rubber bushing of vehicle system
… of rubber bushing. Based on experimental modal analysis, the sandwich cylindrical rubber bushing is treated as multi-body. With the multi-body model, the transfer function of the rubber bushing is calculated in order to estimate the dynamic response. The second innovation comes from the …
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Experimental Damage Diagnosis of a Model Three-Story Spatial Frame
… metal frame building was constructed. Using Star Modal software, dynamic structural properties were obtained from modal decomposition on experimental tap test responses. The natural frequencies and mode shapes of the structure established an as-built baseline for comparison to ten other scenarios …
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Dynamics and Control of a Pressurized Optical Membranes
Optical membranes are currently pursued for their ability to replace the conventional mirrors that are used to correct wave front aberration and space-based telescopes. Among some of the many benefits of using optical membranes, is their ability to considerably reduce the weight of the structure. …