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Showing 1 to 20 of 225 for “"Natural Frequency"”.
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Fundamental Natural Frequency of Steel Joist Supported Floors
Three aspects in determining the first natural frequency of steel joist supported floors were studied. The aspects are: 1) determining which finite element model best predict the behavior of joist-slab tee-beams, 2) investigating the ability of proposed equations to calculate the effective moment …
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An Analytical Investigation of Natural Frequency for a Symmetric Composite Box-Beam with Thermal Effects
… develop an analytical method for determining the natural frequency of a symmetric composite box-beam subjected to temperature gradient. A set of coupled partial differential equations of motion is obtained by means of small defection theory and D'Alembert's method. The Smith and Chopra stiffness …
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Frequency estimation of pre-stressed and composite floors
… be avoided by ensuring a high floor fundamental natural frequency and damping. There is a need, therefore, for a method to accurately predict the fundamental natural frequency and damping of these floors and to ensure that they are high enough to avoid any resonance or perceptibility problems. …
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Assessment of catheter-manometer systems used for invasive blood pressure measurement
… and in vivo evaluations were performed. The frequency response (described in terms of damped natural frequency and damping factor) for a variety of cannulae, pressure tubing and stopcocks (and combinations thereof) and their dependence on various parameters (catheter length, lumen diameter, …
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Adaptive tuned vibration absorber
… vibration absorber is capable of detecting the frequency of the driving force and tuning itself automatically to that particular frequency. The primary structure was previously designed to obtain a certain natural frequency. The absorber structure was previously designed so that its range of …
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Forcing of globally unstable jets and flames
… stable. They respond only at the forcing frequency. Other flames, such as a jet diffusion flame, are hydrodynamically globally unstable. They oscillate at their own natural frequencies and are often assumed to be insensitive to low-amplitude forcing at other frequencies. If a …
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USING TRANSCRANIAL MAGNETIC STIMULATION TO EXAMINE AND MODULATE BRAIN CIRCUITS IN SCHIZOPHRENIA
… activity, particularly in the beta and gamma frequency bands, might be implicated in the pathophysiology of schizophrenia. Evidence from studies employing electroencephalography (EEG) across several paradigms (resting state, steady state, sensory event-related, task-related, etc.) suggests …
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Improving the vibrational performance of wood floor systems
… behavior of stiffened plates. By con1paring natural frequency, time-history, and power density predictions with experimental results, it is shown that the model can be used to predict the vibratory behavior of wood floor systems constructed With either solid-sawn joists, I-Joists, or …
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Statistical response predictions in complex systems with dissipation
… of dissipation on the intermodal correlations of natural frequency spectra are explored. It is found that for moderate damping the modal decay rates of complex systems are distributed according to a modified chi square distribution whose degree depends on the spatial distribution of lossy material …
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Rail Wheel Noise in Road to Rail Maintenance of Way Vehicles
… through testing to be the result of a resonant natural frequency response in the railgear excited by manufacturing irregularities in the rail wheels. To dampen the resonant natural frequency response and improve the operator experience using railgear equipped vehicles manufacturing changes were …
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Optimization and Modeling Tools for Telescope Hexapod Structures
… element in many mechanical design systems. The natural frequency and stiffness behavior under geometric and mass variations of such structures is largely undocumented. Furthermore, the ability to quickly model hexapod designs and explore a large design-space in finite element software packages …
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A vibration-based bridge scour monitoring technique
… changes in dynamic modal parameters (e.g. the natural frequency of vibration) captured by sensors mounted on the bridge deck or piers above the water level. There has been extensive research into the use of vibration-based monitoring methods to identify other causes of failure, such as cracking …
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Nonlinear oscillations of self-excited systems under multifrequency parametric excitation
… system with weak nonlinearities and multifrequency parametric excitation is investigated in this study. The method of multiple scales is used to analyze the system under four different resonances relating parametric excitation frequencies with the natural frequencies. In the first case, …
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Dynamic Response of Tuned Secondary Systems
… of secondary systems that are tuned to a natural frequency of the primary system.
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Nonlinear Vibrations of Cantilever Beams and Plates
… be a function of the closeness of the modulation frequency to the natural frequency of the first mode. The modulation frequency, which depends on various parameters like the amplitude and frequency of excitation, damping factors, etc., has to be near the natural frequency of the low-frequency mode …
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Effects of Seated Whole-Body Vibration on Spinal Stability Control
… third study was to measure the changes in the natural frequency characteristics of the trunk (which can be related to trunk stiffness and damping) during exposure to seated whole-body vibration. The findings show that whole-body vibration caused a decrease in natural frequency suggesting a …
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Nonlinear dynamics of systems involving widely spaced frequencies
… presented. The beam is excited near its fifth natural frequency but sustained large-amplitude oscillations of the first mode accompanied by modulated oscillations of the fifth mode occur. Thus, energy is transferred from the fifth to the first mode of the beam, whose natural frequencies are …
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Effects of Bottom Chord Extensions on the Static and Dynamic Performance of Steel Joist Supported Floors
… of bottom chord extensions on deflections, natural frequency, damping, mode shape and effective mass, extensive analytical and experimental studies were conducted on single span and three span joist supported laboratory footbridges with different bottom chord extension configurations. Finite …
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