scholarly journals Effect of Modulated Signals on Vibrational Resonance in a Harmonically Trapped Potential System

2021 ◽  
Vol 13 (3) ◽  
pp. 797-807
Author(s):  
B. Bhuvaneshwari ◽  
S. V. Priyatharsini ◽  
V. Chinnathambi ◽  
S. Rajasekar
Keyword(s):  
Low Frequency ◽  
Response Amplitude ◽  
External Signal ◽  
Amplitude Curve ◽  
Vibrational Resonance ◽  
Potential Wells ◽  
Fm Signals ◽  
Potential System ◽  
Single Well ◽  
Modulated Signals

We consider a harmonically trapped potential system driven by modulated signals with two widely different frequencies ω and Ω, where Ω >> ω. The forms of modulated signals are amplitude modulated (AM) and frequency-modulated (FM) signals. An amplitude-modulated external signal is consisting of a low-frequency (ω) component and two high-frequencies (Ω + ω) and (Ω − ω) whereas the frequency modulated signal consisting of the frequency components such as f sinωt cos(g cosΩt) and f sin(g cosΩt) cosωt. Depending upon the values of the parameters in the potential function, an odd number of potential wells of different depths can be generated. We numerically investigate the effect of these modulated signals on vibrational resonance (VR) in single-well, three-well, five-well and seven-well potentials. Different from traditional VR theory in the present paper, the enhancement of VR is made by the amplitudes of the AM and FM signals. We show the enhanced response amplitude (Q) at the low-frequency ω, showing the greater number of resonance peaks and non-decay response amplitude on the response amplitude curve due to the modulated signals in all the potential wells. Furthermore, the response amplitude of the system driven by the AM signal exhibits hysteresis and a jump phenomenon. Such behavior of Q is not observed in the system driven by the FM signal.

Vibrational Resonance in an Overdamped System with a Fractional Order Potential Nonlinearity

2018 ◽  
Vol 28 (07) ◽  
pp. 1850082 ◽  
Author(s):  
Jianhua Yang ◽  
Dawen Huang ◽  
Miguel A. F. Sanjuán ◽  
Houguang Liu
Keyword(s):  
Numerical Simulation ◽  
Nonlinear System ◽  
Theoretical Analysis ◽  
Fractional Order ◽  
Low Frequency ◽  
Response Amplitude ◽  
Resonance Phenomenon ◽  
Vibrational Resonance ◽  
Frequency Excitation ◽  
Overdamped System

We investigate the vibrational resonance by the numerical simulation and theoretical analysis in an overdamped system with fractional order potential nonlinearities. The nonlinearity is a fractional power function with deflection, in which the response amplitude presents vibrational resonance phenomenon for any value of the fractional exponent. The response amplitude of vibrational resonance at low-frequency is deduced by the method of direct separation of slow and fast motions. The results derived from the theoretical analysis are in good agreement with those of numerical simulation. The response amplitude decreases with the increase of the fractional exponent for weak excitations. The amplitude of the high-frequency excitation can induce the vibrational resonance to achieve the optimal response amplitude. For the overdamped systems, the nonlinearity is the crucial and necessary condition to induce vibrational resonance. The response amplitude in the nonlinear system is usually not larger than that in the corresponding linear system. Hence, the nonlinearity is not a sufficient factor to amplify the response to the low-frequency excitation. Furthermore, the resonance may be also induced by only a single excitation acting on the nonlinear system. The theoretical analysis further proves the correctness of the numerical simulation. The results might be valuable in weak signal processing.

scholarly journals NUMERICAL INVESTIGATION OF SIGNAL AMPLIFICATION VIA VIBRATIONAL RESONANCE IN CHUA'S CIRCUIT

2020 ◽  
Vol 6 ◽  
pp. 14
Author(s):  
John Abidemi Laoye ◽  
Taiwo Olakunle Roy-Layinde ◽  
Kehinde Adam Omoteso ◽  
Rasaki Kola Odunaike
Keyword(s):  
Low Frequency ◽  
Response Amplitude ◽  
Chua’S Circuit ◽  
Response Curves ◽  
Vibrational Resonance ◽  
Periodic Force ◽  
Chua's Circuit ◽  
Chua’S Oscillator ◽  
Conductance Parameter ◽  
Cubic Polynomial

In this paper, we numerically investigated the occurrence of Vibrational Resonance in a modified Chua's oscillator with a smooth nonlinearity, described by a cubic polynomial. Response curves generated from the numerical simulation at the low frequency reveal that the system's response amplitude could be controlled by modulating the conductance parameter of the Chua's circuit, rather modulating the parameters of the fast-periodic force. Modulating the frequency of the fast-periodic force slightly reduces the response amplitude; shifts the peak point to a higher value of the amplitude of the fast-periodic force by widening the resonance curves. Within certain parameter regime of the high frequency (Ω >100ω), the system's response gets saturated, and further increase does not affect its amplitude.

Vibrational Resonance in a Fractional Order Quintic Oscillator System with Time Delay Feedback

2020 ◽  
Vol 30 (02) ◽  
pp. 2050025 ◽  
Author(s):  
Wen Guo ◽  
Lijuan Ning
Keyword(s):  
Time Delay ◽  
Fractional Order ◽  
Bifurcation Point ◽  
Low Frequency ◽  
Approximate Expression ◽  
Vibrational Resonance ◽  
Point Change ◽  
Oscillator System ◽  
Single Well ◽  
System With Time Delay

Vibrational resonance is studied in a fractional order quintic oscillator system with delayed feedback. By utilizing the perturbation theory, the theoretical approximate expression of the response amplitude at low-frequency is obtained. In the presence of fractional order and time delay, resonance phenomena are studied in the single-well, double-well and triple-well potentials, respectively. Meanwhile, the good agreement between theoretical prediction and numerical simulation verifies the validity of theoretical analysis. It is found that by altering the fractional order derivative, the occurrence of new resonances is more frequent. As delay increases, the bifurcation point and the equilibrium point change periodically. In addition, fractional order, time delay feedback and high-frequency force amplitude can be appropriately selected to achieve the goal of maximizing the output in different systems. In particular, an intersection that affects the triple-well potential bifurcation point was found.

Optimum Vibrational Resonance in a Time-Delay Bistable System Driven by Biharmonic Signals

2014 ◽  
Vol 651-653 ◽  
pp. 2172-2176
Author(s):  
Yun Liang Meng ◽  
Chang Xing Pei ◽  
Dong Wu Li
Keyword(s):  
Time Delay ◽  
High Frequency ◽  
Low Frequency ◽  
Signal Amplitude ◽  
Resonance Peak ◽  
Response Amplitude ◽  
Bistable System ◽  
Vibrational Resonance ◽  
Frequency Signal ◽  
High Frequency Signal

The optimum vibrational resonance in a time-delay bistable system driven by bihiarmonic signals is discussed in this paper. The theoretically expression for the response amplitude gain of low frequency signal in the time-delay bistable system is deduced, and the effects of time delay parameter on the optimum vibrational resonance peak and the required amplitude of high frequency signal are investigated. It is shown that the optimum vibrational resonance can be achieved by adjusting the high frequency signal amplitude and time delay parameter jointly. Meanwhile, the optimum vibrational resonance appeared periodically with time delay parameter and the period is equal to the period of low-frequency signal. The amplitude of high-frequency signal required for the optimum vibrational resonance can be fixed or varied with different time delay parameter depending on the ratio of the frequencies between biharmonic signals.

Delineating a cased borehole in unconsolidated formations using dipole acoustic data from a nearby well

Geophysics ◽  
2021 ◽  
pp. 1-39
Author(s):  
Gu Xihao ◽  
Xiao-Ming Tang ◽  
Yuan-Da Su
Keyword(s):  
Shear Waves ◽  
Low Frequency ◽  
Well Being ◽  
Compressional Wave ◽  
Acoustic Imaging ◽  
Wave Radiation ◽  
Dipole Source ◽  
Compressional Waves ◽  
Single Well ◽  
Cased Borehole

A potential application for single-well acoustic imaging is the detection of an existing cased borehole in the vicinity of the well being drilled, which is important for drilling toward (when drilling a relief well), or away from (collision prevention), the existing borehole. To fulfill this application in the unconsolidated formation of shallow sediments, we propose a detection method using the low-frequency compressional waves from dipole acoustic logging. For this application, we perform theoretical analyses on elastic wave scattering from the cased borehole and derive the analytical expressions for the scattered wavefield for the incidence of compressional and shear waves from a borehole dipole source. The analytical solution, in conjunction with the elastic reciprocity theorem, provides a fast algorithm for modeling the whole process of wave radiation, scattering, and reception for the borehole acoustic detection problem. The analytical results agree well with those from 3D finite-difference simulations. The results show that compressional waves, instead of shear waves as commonly used for dipole acoustic imaging, are particularly advantageous for the borehole detection in the unconsolidated formation. Field data examples are used to demonstrate the application in a shallow marine environment, where dipole-compressional wave data in the measurement well successfully delineate a nearby cased borehole, validating our analysis results and application.

Suppression of Cross-Well Oscillations for Bistable Composites Through Potential Well Elimination

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Andrew J. Lee ◽  
Antai Xie ◽  
Daniel J. Inman
Keyword(s):  
Control Strategy ◽  
Stable State ◽  
Fiber Composites ◽  
Piezoelectric Transducers ◽  
Low Frequencies ◽  
Potential Wells ◽  
Single Well ◽  
Control Capability ◽  
Bistable Structures ◽  
Stationary Control

Abstract Although there have been numerous efforts into harnessing the snap through dynamics of bistable structures with piezoelectric transducers to achieve large energy conversion, these same dynamics are undesirable under morphing applications where stationary control of the structure’s configuration is paramount. To suppress cross-well vibrations that primarily result from periodic excitation at low frequencies, a novel control strategy is proposed and implemented on the piezoelectrically generated bistable laminate, which consists of only macro fiber composites (MFCs) in a [0MFC/90MFC]T layup. While under cross-well regimes such as subharmonic, chaotic, or limit cycle oscillations, a single MFC is actuated to the laminate’s limit voltage to eliminate one of its potential wells and force it into the remaining stable state. Simultaneously, a positive position feedback (PPF) controller suppresses the resulting single-well oscillations through the other MFC. This dual control strategy is numerically and experimentally demonstrated through the suppression of various cross-well regimes and results in significant reduction of amplitude. The active control capability of the laminate prevents snap through instability when under large enough external vibrations.

Optimizing the Electrical Power in an Energy Harvesting System

2015 ◽  
Vol 25 (12) ◽  
pp. 1550171 ◽  
Author(s):  
Mattia Coccolo ◽  
Grzegorz Litak ◽  
Jesús M. Seoane ◽  
Miguel A. F. Sanjuán
Keyword(s):  
Energy Harvesting ◽  
Kinetic Energy ◽  
High Frequency ◽  
Energy Harvester ◽  
Electrical Power ◽  
Low Frequency ◽  
Electrical Energy ◽  
Resonance Phenomenon ◽  
Vibrational Resonance ◽  
Energy Harvesting System

In this paper, we study the vibrational resonance (VR) phenomenon as a useful mechanism for energy harvesting purposes. A system, driven by a low frequency and a high frequency forcing, can give birth to the vibrational resonance phenomenon, when the two forcing amplitudes resonate and a maximum in amplitude is reached. We apply this idea to a bistable oscillator that can convert environmental kinetic energy into electrical energy, that is, an energy harvester. Normally, the VR phenomenon is studied in terms of the forcing amplitudes or of the frequencies, that are not always easy to adjust and change. Here, we study the VR generated by tuning another parameter that is possible to manipulate when the forcing values depend on the environmental conditions. We have investigated the dependence of the maximum response due to the VR for small and large variations in the forcing amplitudes and frequencies. Besides, we have plotted color coded figures in the space of the two forcing amplitudes, in which it is possible to appreciate different patterns in the electrical power generated by the system. These patterns provide useful information on the forcing amplitudes in order to produce the optimal electrical power.

Ultrasound-sensitive neurons descending in the thoracic nervous system of the cricket Teleogryllus oceanicus

1984 ◽  
Vol 62 (4) ◽  
pp. 555-562 ◽  
Author(s):  
Gerald S. Pollack
Keyword(s):  
Nervous System ◽  
High Frequency ◽  
Low Frequency ◽  
Response Amplitude ◽  
Calling Song ◽  
Teleogryllus Oceanicus ◽  
Response Characteristics ◽  
Prothoracic Ganglion ◽  
Neuronal Types

Responses were recorded from descending, ultrasound-sensitive interneurons in the promesothoracic connectives of the cricket Teleogryllus oceanicus. The cells were most sensitive to sounds with frequencies of 20–50 kHz. Cells differed in their directionality characteristics; some were most sensitive to ipsilateral sounds, and some were most sensitive to contralateral sounds. Consideration of other response characteristics, such as latency, spiking pattern, and response amplitude, suggests that both directionality classes may contain several neuronal types. Many, though not all, of the cells ceased responding when the connections between the prothoracic ganglion and the head ganglia were severed. Two-tone experiments were performed, and these demonstrated that the responses to high frequency sounds were suppressed by simultaneously presented low frequency sounds. Suppressing frequencies near that of the species' calling song were most effective. The presumed roles of neurons sensitive to high frequency sounds are compared between T. oceanicus and other species.

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