On Quality Factor Improvement in a NEMS Resonator With Nonlinear Damping

2019 ◽  
Author(s):  
Subramanian Ramakrishnan ◽  
Md Raf E Ul Shougat
Keyword(s):  
White Noise ◽  
Harmonic Balance ◽  
Nonlinear Damping ◽  
Damping Coefficient ◽  
White Noise Excitation ◽  
Sensing Applications ◽  
Method Of Harmonic Balance ◽  
Strong Excitation ◽  
Q Factors ◽  
Relationship Of

Abstract Nonlinear damping effects have been reported in experiments on nanoelectromechanical (NEMS) resonators and suggested as a pathway to improve the quality (Q) factors of the resonators. In particular, in a nonlinearly damped Duffing NEMS resonator operating in the hardening regime, it has been shown that white noise excitation can shrink the hysteresis region resulting in higher Q factors. In this paper the authors: (1) find that an analytical expression they previously derived using the method of harmonic balance for the frequency-amplitude relationship of a weakly-excited, nonlinearly damped Duffing NEMS resonator is valid for strong excitation, (2) show analytically and verify numerically that for constant values of the nonlinear damping coefficient, higher amplitude of forcing leads to increase in the resonant frequency, (3) find that white-noise induced stochastic parametric excitation can lead to enhanced Q factors and (4) show that decreasing the nonlinear damping coefficient leads to higher Q-factor. The results, in addition to being theoretically significant, are expected to be important in sensing applications using NEMS resonators.

scholarly journals Stochastic P-bifurcation in a bistable Van der Pol oscillator with fractional time-delay feedback under Gaussian white noise excitation

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Yajie Li ◽  
Zhiqiang Wu ◽  
Guoqi Zhang ◽  
Feng Wang ◽  
Yuancen Wang
Keyword(s):  
Time Delay ◽  
White Noise ◽  
Gaussian White Noise ◽  
Singularity Theory ◽  
Van Der Pol Oscillator ◽  
Order System ◽  
Damping Force ◽  
Van Der Pol ◽  
Restoring Force ◽  
White Noise Excitation

Abstract The stochastic P-bifurcation behavior of a bistable Van der Pol system with fractional time-delay feedback under Gaussian white noise excitation is studied. Firstly, based on the minimal mean square error principle, the fractional derivative term is found to be equivalent to the linear combination of damping force and restoring force, and the original system is further simplified to an equivalent integer order system. Secondly, the stationary Probability Density Function (PDF) of system amplitude is obtained by stochastic averaging, and the critical parametric conditions for stochastic P-bifurcation of system amplitude are determined according to the singularity theory. Finally, the types of stationary PDF curves of system amplitude are qualitatively analyzed by choosing the corresponding parameters in each area divided by the transition set curves. The consistency between the analytical solutions and Monte Carlo simulation results verifies the theoretical analysis in this paper.

scholarly journals Functional analysis and the method of harmonic balance

1975 ◽  
Vol 32 (4) ◽  
pp. 457-464 ◽  
Author(s):  
C. A. Borges ◽  
L. Cesari ◽  
D. A. Sánchez
Keyword(s):  
Functional Analysis ◽  
Harmonic Balance ◽  
Method Of Harmonic Balance

Model Reduction of Piezoelectric Energy Harvesters Subject to Band-Limited, Stochastic Base Excitation

2012 ◽  
Author(s):  
Adam M. Wickenheiser
Keyword(s):  
White Noise ◽  
Design Optimization ◽  
Broadband Noise ◽  
Degree Of Freedom ◽  
Single Degree Of Freedom ◽  
Energy Harvesters ◽  
White Noise Excitation ◽  
Single Degree ◽  
Piezoelectric Energy ◽  
Band Limited

In many scenarios where vibration energy harvesting can be utilized — particularly those involving bio-motions or environmental disturbances — energy sources are broadband and non-stationary. On the other hand, design procedures have been predominantly developed for harmonic or white noise excitation, specifically for single degree of freedom approximations of the transducer. In this paper, a general approach for design optimization of cantilevered, piezoelectric energy harvesters in the presence of band-limited, white-noise excitation is outlined. For this study, human and vehicular motions are considered; these complex waveforms are distilled into a small set of dominant features with regard to their impact on the power output of the device. Criteria based on modal participation factors, including pre-filtering of the disturbance, are used in guiding the reduction of the input and plant degrees of freedom in order to make the design optimization problem tractable. This process determines the error in assuming a low-order model for the transducer in the presence of broadband noise that may excite multiple modes of vibration. Furthermore, this study considers the quantitative impact of charge cancellation in higher modes and the benefits of inserting multiple electrodes along the length. To illustrate these methods, energy harvesters are designed for acceleration data collected from walking and car idling. It is shown that a simple method that is a generalization of naïve approaches that assume harmonic or white noise excitation and a single degree of freedom can determine which simplifications are appropriate and the inaccuracies that can be expected from them.

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