arXiv subjects

Ivan Skhem Sawkmie

Publications and source records attributed to Ivan Skhem Sawkmie.

3 recordsLinked to original sources

arXiv2021

Theoretical and numerical study of vibrational resonance in a damped softening Duffing oscillator

We study the possibility of occurrence of vibrational resonance in a softening Duffing oscillator in the underdamped and overdamped cases both theoretically as well as numerically. The oscillator is driven by two periodic forces. Numerically we find that in the underdamped case two oscillatory solutions are obtained in a limited range of the parameters considered (damping coefficient and amplitude of the high frequency force) for a fixed frequency and amplitude of the low frequency periodic force depending on the initial conditions. These solutions have distinct response amplitude to the low frequency force. When damping is gradually increased, only one oscillatory solution is observed. Vibrational resonance is observed in both the regions of oscillation. The analytical approximation yields only one oscillatory solution for all damping values. Analytically, the peak in the area bounded by the phase portrait as a function of the amplitude of the high frequency force is connected to vibrational resonance. Also, the values of the frequency of the low frequency forcing and the amplitude of the high frequency forcing at which vibrational resonance is found to occur are obtained. In the overdamped case, vibrational resonance is not observed for the softening Duffing oscillator thus showing a marked contrast to the overdamped bistable oscillator

nlin.CD↗

arXiv2019

An analog simulation experiment to study free oscillations of a damped simple pendulum

The characteristics of drive-free oscillations of a damped simple pendulum under sinusoidal potential force field differ from those of the damped harmonic oscillations. The frequency of oscillation of a large amplitude simple pendulum decreases with increasing amplitude. Many prototype mechanical simple pendulum have been fabricated with precision and studied earlier in view of introducing them in undergraduate physics laboratories. However, fabrication and maintenance of such mechanical pendulum require special skill. In this work, we set up an analog electronic simulation experiment to serve the purpose of studying the force-free oscillations of a damped simple pendulum. We present the details of the setup and some typical results of our experiment. The experiment is simple enough to implement in undergraduate physics laboratories.

physics.class-ph↗

arXiv2018

Stochastic resonance in a sinusoidal potential system: An analog simulation experiment

Recently, stochastic resonance was obtained numerically in an underdamped periodic potential system driven by a periodic force and a Gaussian white noise. In that numerical work, the occurrence of stochastic resonance was explained in terms of the existence of two dynamical states having different amplitude and phase lag. At zero temperature these two initial condition dependent dynamical states are stable. However, at elevated temperatures, these two states make transitions from one to the other at a mean rate. In the present work, we setup an analog simulation experiment to show the existence of the two dynamical states in a sinusoidal potential system as well as to verify the occurrence of stochastic resonance in the same system. The experimental procedure includes setting the initial conditions for the experiment.

nlin.CD↗