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 “"Vibration Attenuation"”.
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Vibration Attenuation of Composite Moving Beams using Active Vibration Control Techniques
… studies have shown that the amplitude of lateral vibration of moving beams is 40 percent higher than that of non moving beams. In this research a numerical model based on the finite element method is done to reduce the excess vibrations caused by the axial oscillation of the beam. A computer code …
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Nonlinear Mechanical Metamaterial: A Novel Approach Towards Wideband Sound and Vibration Attenuation
… become very popular in the field of noise and vibration suppression, cloaking, wave guide, wave shield, wave absorber owing to its frequency dependent material properties. However, due to the dependency on the linear resonance, the performance of a linear metamaterial is restricted to a narrow …
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The study and development of distributed devices for concurrent vibration attenuation and energy harvesting
This work focuses on the broadband attenuation of structural vibration and, in the process, employs a new perspective of vibrational energy harvesting devices. The first part of the research studies and develops a continuously distributed vibration control device which combines the benefits of …
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Application of smart materials for vibration reduction in ships
… industries to measure and control noise and vibration. This study covered ship structure vibration and Smart Materials were employed for the purpose of ship vibration attenuation. One specific Smart Material, piezoelectric material, was the focus of the study. Although previous research has …
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Objective assessment of static and dynamic seats under vehicular vibrations
… seats are reviewed. A comparative study of vibration transmission performance of the seats obtained with a number of subjects representing 50 th percentile male population and with an equivalent passive load is performed. The experimental results are used to identify a Human Response …
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Analysis of a Nonlinear vibration absorber for vibration control in a hand-held impact machine
… approximately 20% of operators risk developing vibration-related hand injuries, which can be career-ending. As a step toward improving the safety of these tools, this dissertation focuses on modeling their dynamic behavior to evaluate the effectiveness of vibration control strategies. The …
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Theoretical and Experimental Studies of Manipulation of Elastic Waves in Helix Metamaterials
… bandgap; Controllable design; Laser vibration measurement; Strong vibration attenuation; Carrera Unified Formulation Abstract Elastic metamaterials exhibit mechanical properties unattainable in natural materials and demonstrate vast potential in vibration and noise reduction, acoustic …
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MITIGATION OF GEAR MESH-FREQUENCY VIBRATIONS UTILIZING A HYDROSTATIC BEARING
… noises are symptoms of gear mesh-frequency vibrations which are ever-present due to the imperfect conjugate action between the gears. These vibrations are then transferred to the gear housing to be emitted as noise. The vibration energy flow can be disrupted, for example using a hydrostatic …
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The effect of wing flexibility on ride comfort in formation flight
… formation flight. The study focuses on the vibration attenuation that occurs due to the aeroelastic effect, more particularly, on the influences these effects have on the magnitude of the fuselage accelerations. No distinction is made between the fuselage and passenger accelerations in the …
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Modeling and Estimation of Linear and Nonlinear Piezoelectric Systems
… Oscillator Arrays (PSOAs) for the wideband vibration attenuation problem. PSOAs offer a straightforward and low mass ratio solution to cancel out the resonant peaks in a host structure's frequency domain. Further, they provide adaptability through shunt tuning, which gives them the ability …
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Analytical and Spectro-Spatial Analyses of Nonlinear Metamaterials for Vibration Control, Energy Harvesting, and Acoustic Non-Reciprocity
… be used for simultaneous energy harvesting and vibration attenuation without any degradation in the size of bandgaps. Spectro-spatial analyses conducted on the electromechanical metamaterial also reveal the presence of solitons and frequency shifts. The presence of solitary wave in the …
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Analysis of Linear and Nonlinear Quasiperiodic Metamaterials with Local Resonators
… bandgaps are created, which provide stronger vibration attenuation and display coupled topological and locally resonant behavior. Finally, a thorough parametric study is performed for each case to guide designers in selecting ideal parameters and pattering for a variety of applications. The …
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Study on Bandgap Manipulation and Structural Vibration Control in Sandwich Metastructures
… exposed to problematic medium- and low-frequency vibrations induced by operational loads, environmental disturbances, and earthquakes. Although conventional vibration isolation and mitigation methods have been widely used, they still face limitations in broadband control of medium- and …
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Predicting the vibration discomfort of standing passengers in transport
It has previously been assumed that the vibration discomfort of standing people can be<br/>estimated using the same procedures developed from for seated people. In this thesis, the<br/>discomfort of standing people exposed to vibration was investigated to improve understanding<br/>of the mechanisms …
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Free and Forced Vibration of Linearly Elastic and St. Venant-Kirchhoff Plates using the Third Order Shear and Normal Deformable Theory
… study three problems involving free and forced vibrations of linearly and nonlinearly elastic plates with a third order shear and normal deformable theory (TSNDT) and the three dimensional (3D) elasticity theory. We used the commercial software ABAQUS for analyzing 3D deformations, and an …
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Advanced Control Strategies for Mobile Hydraulic Applications
… dynamics, mainly discontinuous motion and vibrations. Over the years, many methods have been developed to limit the extent of those undesired dynamics and improve controllability and safety of operation of the machine. However, in most of the cases, today's methods do not significantly …
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Fatigue, Fracture and Impact of Hybrid Carbon Fiber Reinforced Polymer Composites
… on the in-plane tensile performance and vibration attenuation capabilities of the hybrid CFRPs are investigated via quasi-static tension and dynamical mechanical analysis (DMA) tests, respectively. As a result, the in-plane tensile strength of the hybrid CFRPs were improved by 18% for the …