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 19 of 19 for “"Primary Resonance"”.
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Numerical and Analytical Analysis of Vortex Induced Vibrations of a Pipeline Close to Seabed
… analysed. To get the analytical solutions, the primary resonance is mainly investigated and the amplitude-frequency equations are derived, then the analytical solutions are compared with the numerical solutions of the full model. It is found that the analytical solutions with regard to the …
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Forced, nonlinear, planar and nonplanar oscillations of a cantilvered beam including static deflection
… studies considered whirling produced by a primary resonance. In this dissertation, secondary resonances are considered in addition to primary resonance. Previous derivations of equations of motion contain only the linear and cubic terms without consideration of the static displacement …
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Modal interactions in shell dynamics
… natural frequency of the breathing mode (i.e., primary resonance of the breathing mode) and the linear natural frequency of the breathing mode is approximately twice that of a flexural mode (i.e., two-to-one internal or autoparametric resonance). The method of multiple-time scales is used to …
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A Theoretical and Experimental investigation of Nonlinear Vibrations of Buckled Beams
… single-mode responses of the beam under a primary resonance are generated using both approaches and contrasted with experimentally obtained frequency-response curves. It is shown that discretization leads to erroneous quantitative as well as qualitative results in certain ranges of the …
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Identification and Quantification of Nonlinear Behavior in a Disbonded Aluminum Honeycomb Panel using Single Degree-of-Freedom Models
… of their behavior at specific harmonics of the primary resonance of the system. After an understanding of the approximate behaviors of the models is obtained, experimental tests on a damaged specimen are conducted. An aluminum honeycomb sandwich panel is damaged by applying a heat source to the …
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Nonlinear Forced Vibration of an Unsymmetrically Laminated Composite Beam
… response of the beam associated with the primary resonance was studied. In addition, the subharmonic and superharmonic resonances were analyzed for a simply-supported unsymmetrically laminated angle-ply composite beam. In order to compare the effects of different modes of vibrations, a …
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Nonlinear Vibrations of Doubly Curved Cross-PLy Shallow Shells
… approaches to study the responses of shells to a primary resonance: a $direct$ approach and a $discretization$ approach. In the discretization approach, the nonlinear partial-differential equations are discretized using the Galerkin procedure to reduce them to an infinite system of nonlinearly …
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Coupled oscillators near resonance
… dynamics of these systems when they are near a resonance using secular perturbation theory. We show that near resonance a large class of driven oscillators and two coupled oscillators can be transformed to the same ordinary differential equations (ODEs). We consider two types of resonances: …
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Nonlinear Dynamics of Circular Plates under Electrical Loadings for Capacitive Micromachined Ultrasonic Transducers (CMUTs)
… actuated clamped circular plate to a primary resonance excitation of its first axisymmetric mode. The method of multiple scales was used to derive a semi-analytical expression for the equilibrium amplitude of vibration. The plate was found to always transition from a hardening-type to …
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Nonlinear transverse vibrations of centrally clamped rotating circular disks
… different rotational speeds. We have studied the primary resonance of a pair of orthogonal modes under a space-fixed constant loading, the principal parametric resonance of a pair of orthogonal modes when the disk is subject to a massive loading system, and the combination parametric resonance of …
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Experimental Identification of Nonlinear Systems
A procedure is presented for using a primary resonance excitation in experimentally identifying the nonlinear parameters of a model approximating the response of a cantilevered beam by a single mode. The model accounts for cubic inertia and stiffness nonlinearities and quadratic damping. The method …
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Structural Identification and Buffet Alleviation of Twin-Tailed Fighter Aircraft
… responses of the F-15 fighter to a primary resonance excitation. The control strategies are linear velocity feedback, nonlinear velocity feedback, positive position feedback, and saturation-based control. For each case, we conduct bifurcation analyses for the open- and closed-loop …
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A Theoretical and Experimental Study of Nonlinear Dynamics of Buckled Beams
… of external harmonic excitations and internal resonances. We assume that the beam geometry is uniform and its material is homogeneous. We initially buckle the beam by an axial force beyond the critical load of the first buckling mode, and then we apply a transverse harmonic excitation that is …
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Nonlinear dynamics of composite plates and other physical systems
… solutions in the neighborhoods of different resonances. As an application of the technique, the nonlinear response of a fluid-relief valve is discussed in detail. The different resonances are studied, and in each case the responses are compared to those obtained by using the Galerkin …
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Modal interactions in the dynamic response of isotropic and composite plates
… detail. The case of a two-to-one autoparametric resonance in shear-deformable composite laminated plates is considered. Four first-order ordinary-differential equations describing the modulation of the amplitudes and phases of the internally resonant modes are derived using the averaged …
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Modeling and Simulation of Microelectromechanical Systems in Multi-Physics Fields
… near their fundamental natural frequencies (primary-resonance excitation). We investigate the dynamic pull-in instability and formulate safety criteria for the design of MEMS sensors and RF filters. We also utilize this phenomenon to design a low-voltage RF MEMS switch actuated with a …
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A theoretical and experimental investigation into the nonlinear dynamics of floating bodies
… when either mode is externally excited through a primary resonance. Force-response and frequency-response curves are generated. Coexistence of multiple solutions is found. The jump phenomenon continues to exist, whereas the saturation phenomenon ceases in the presence of quadratic damping. Hopf …
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Modeling, Simulation, and Analysis of Micromechanical Filters Coupled with Capacitive Transducers
… expressions for the response of the filter to a primary resonance. The third objective is to investigate the feasibility of employing subharmonic excitation to build bandpass filters consisting of either two sets of two beams coupled mechanically or two sets of clamped-clamped beams. Throughout …
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Mechanism of nonlinear biodynamic response of the human body exposed to whole-body vibration
… body is exposed to mechanical vibration, the resonance frequencies of the frequency response functions, such as apparent mass and transmissibility, decrease with increasing magnitude of excitation. For the past two decades, this biodynamic ‘nonlinearity’ has been reported with vertical and …