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Showing 1 to 19 of 19 for “"base excitation"”.
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Transient and Spectral Fatigue Analysis for Random Base Excitation
… stress states in case of random vibration base excitation. The transient method involves a rainflow count algorithm that counts the number of cycles causing the fatigue damage, while the spectral method is based on probabilistic assumptions from which an expected value of fatigue damage can …
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The Experimental Testing of an Active Magnetic Bearing/Rotor System Undergoing Base Excitation
… This paper will focus on the effects of direct base excitation to an AMB/rotor system because base excitation is highly possible to occur in vehicular applications. This type of excitation has been known to de-stabilize AMB/rotor systems therefore this aspect of AMB system operation needs to be …
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A study of seismic response of rotating machines subjected to multi-component base excitation
… by the presence of earthquake induced base motions. The response spectrum methods, which are now commonly used for calculating seismic design response of civil structures, cannot be used as such for calculating the design response of rotating machines. In this thesis, a response …
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Analysis of Buckled and Pre-bent Columns Used as Vibration Isolators
… or dissipating the energy caused by external excitation. When a base excitation is applied, the buckled strut may act to reduce the dynamic force transmitted to the system, thus reducing the structural damage to the system. Several models of buckled and pre-bent struts are examined with …
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Constructive utilization of intentional nonlinearity in systems of coupled micro/nanomechanical resonators
… with an attached nanotube and harmonic base excitation we report expansion of its resonance bandwidth through by the geometric nonlinearity generated by the flexibility of the nanotube, as well as strong nonlinear damping effects. These nonlinearities have significant influence of the …
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Intentional nonlinearity in the small scale with applications to atomic force microscopy (AFM) and mass sensing
… mode AFM is studied. The system consists of a base cantilever with an inner paddle which, under harmonic excitation, vibrates like a system of linearly coupled oscillators engaging simultaneously a lower, in-phase and a higher, out-of phase resonant mode. The cantilever is designed so that the …
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Airflow sensing with arrays of hydrogel supported artificial hair cells
… artificial hair cell (AHC) sensors based on bilayer membrane mechanotransduction are designed and characterized to determine sensitivity to multiple stimuli. The work draws upon key engineering design principles inspired by the characteristics of biological hair cells, primarily the …
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Multifunctional Piezoelectric Energy Harvesting Concepts
… self-charging structure subjected to harmonic base excitation is described. Experimental evaluation of a prototype self-charging structure is then performed in order to validate the electromechanical model and to confirm the ability of the device to operate in a self-charging manner. Detailed …
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Multi-source Energy Harvesting for Wildlife Tracking
… harvester can provide 200~300 mW under the 0.4g base excitation of 4.5 Hz. The nonlinearity of the disengage mechanism in the pendulum energy harvester will lead to a broad bandwidth frequency response. Simulation results shows the broadband advantage of the proposed energy harvester and …
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Vibration mitigation methods for industrial machinery
… The first publication presents an amplitude-based linearization scheme and experimental identification method for the wire rope isolators. The identified model was shown to accurately capture the nonlinear behavior and provided good agreement with base excitation experiments. The second …
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Development of a Multi-Body Nonlinear Model for a Seat-Occupant System
… behavior of foam was investigated. The model is based on the assumption that the total stress can be decomposed into the sum of a nonlinear elastic component, modeled by a higher order polynomial of strain, and a nonlinear hereditary type viscoelastic component. System identification procedures …
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Nonlinear stochastic vibration analysis for energy harvesting and other applications
… a given vibration source. Initially, white noise base excitation of a general nonlinear energy harvester model is considered. The power input from white noise is known to be proportional both to the total oscillating mass of the system and the magnitude of the noise spectral density, regardless of …
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A theoretical and experimental investigation of parametrically excited nonlinear mechanical systems
… principal, and combination harmonic parametric excitations is investigated theoretically and experimentally. The method of multiple scales (MMS) is used to determine the equations that describe to first and second order the amplitude- and phase-modulations with time. These equations are used to …
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Electromechanical Modeling of Piezoelectric Energy Harvesters
Vibration-based energy harvesting has been investigated by several researchers over the last decade. The ultimate goal in this research field is to power small electronic components (such as wireless sensors) by using the vibration energy available in their environment. Among the basic transduction …
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Modelling and Measurement of the Response of a Beam Interacting with a Polyurethane Foam Foundation
… experimental rig was designed and a variety of base excitation experiments were conducted. Predicted and measured responses were compared and additional experiments were conducted to improve estimates of foundation material and beam model. There is a good qualitative agreement between the …
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Vibration Measurement Based Damage Identification for Structural Health Monitoring
… is on the development of vibration response-based damage detection in civil engineering structures. Modal parameter-based and model identification-based approaches have been considered. In the modal parameter-based approach, the flexibility and curvature flexibility matrices of the structure …
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Semi-active damping control for vibration isolation of base disturbances
… damping control for vibration isolation of base disturbances. The aim is to investigate the effectiveness and suitability of semi-active damping control strategies for improving steady-state vibration isolation. A single-degree-of-freedom (SDOF) system, comprising a semi-active damper with a …
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Modeling of Nonlinear Unsteady Aerodynamics, Dynamics and Fluid Structure Interactions
… vibration system. This system consists of a base structure and a cantilever beam with a tip mass. The dynamic equations for the system are derived using the extended Hamilton's principle. The method of multiple scales is then used to analytically determine the stability and bifurcation of the …
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Ultra-low and wide bandwidth vibrational energy harvesting using a statically balanced compliant mechanism
… to address this need. This SBCM is designed based on the concept of stiffness compensation between a linear positive-stiffness component (two double parallelograms in parallel) and a nonlinear negative-stiffness component (two sets of post-buckled fixed-guided compliant beams in parallel). A …