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 13 of 13 for “"dynamic excitation"”.
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Topology optimization of structures subjected to stochastic dynamic excitation
… to obtain the response due to stochastic excitation and perform the sensitivity analysis of these quantities efficiently for large systems. In this research, a direct approach to this problem is proposed, modeling the excitation as a filtered white noise. The excitation model is combined …
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The Response of an Oil Rig Model to Dynamic Excitation
… in this thesis is to examine the structural dynamics of a laboratory scale model of a fixed off-shore oil rig. This work forms part of a general study of condition monitoring. In the early stages, some preliminary theoretical investigations into the effect of structural system parameter …
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Global Dynamic Characterization and Load Rating of Bridge Structures Utilizing Economical Dynamic Excitation Devices
… has been limited by the high cost of the excitation devices that are required for the best data quality. The objective of the research reported herein is to evaluate a low-cost excitation system for multiple-input, multiple-output (MIMO) EMA, enabling the production of accurate estimates …
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Multiple Reference Impact Testing of Bridges Using a Network of Low-Cost Dynamic Exciters
… Analysis (EMA) that can be used to identify the dynamic properties of full-scale bridges. These dynamic properties include natural frequencies, mode shapes, damping ratios, modal scaling and modal flexibility. Since these system properties that are directly related to the mass and stiffness …
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Excitation sources for structural health monitoring of bridges
… techniques that utilize changes to the dynamic characteristics of a structure (i.e. its natural frequencies, mode shapes, and damping properties) as indicators of damage. While conceptually simple, considerable research is still required before VBDD methods can be applied reliably to …
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Magnetomotive dynamics of magnetic particles for optical imaging contrast and elastography
… of the magnetomotive (MM) response under dynamic excitation. Magnetomotive contrast in optical imaging was shown using functionalized protein shell microspheres in a rabbit atherosclerosis model and further improvement in MM OCT imaging speed was demonstrated allowing the rapid acquisition …
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Two Dimensional Analysis of Vibration Isolation of Rigid Bar Supported by Buckled or Pre-bent Struts
… but can also exhibit a low axial stiffness when dynamic excitation is introduced. Three models consisting of buckled or pre-bent struts serving as vibration isolators which support a rigid bar are examined in this research. The three cases studied are 1) two buckled struts supporting a symmetric …
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Vibration Isolation of a Horizontal Rigid Plate Supported by Pre-bent Struts
… and offers a low axial resistance under dynamic excitation, making it ideal for isolating vertical vibrations. In this research, four of these vibration isolators are used to support a rigid, square plate. The symmetric case is analyzed first. Then the plate has a center of mass which is …
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Train-induced dynamic response of railway track and embankments on soft peaty foundations
… these railway track and embankment structures to dynamic train loading. The displacements were monitored for two different embankments under a variety of loading conditions and for various seasonal conditions. These displacements were recorded using a sensor created for this task. The sensor …
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Mechanical behavior of elastic rods under constraint
… for mitigation of these instabilities by dynamic excitation of the constraint. First, we consider the role of natural curvature in determining the shape of a hanging elastic rod suspended under its own weight. We categorize three distinct configurations: planar hooks, localized helices, …
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Assessment of seismic damage to civil structures using statistical pattern recognition techniques and time series analysis
… by analysing the structural response under dynamic excitation. In the first approach, basic structural and ground motion properties were used to characterise a broad group of structures and earthquakes. These properties were used as inputs into a Back-Propagation (BP) Artificial Neural …
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Analysis of the sensing region of a PZT actuator-sensor
… to provide a low-power driven constant voltage dynamic excitation, and to record the modulated current flow through the structure. Therefore, it relies on tracking the electrical point impedance to identify incipient level damage. The high frequency excitation provided by the PZT, ensures the …
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Dynamická analýza lehké mostní konstrukce
… práce se zabývá odezvou lehké zavěšené lávky na dynamické buzení chodci a seismickým zatížením. Lávka byla modelována pomocí metody konečných prvků v softwaru Ansys verze 15.0 a zároveň také v softwaru RFEM verze 5.05. Modely byly mezi sebou srovnány. Odezva na dynamické zatížení chodci byla …