Non-smooth approximations of the limiting phase trajectories for the Duffing oscillator near 1:1 resonance (original) (raw)

2011, Physica D: Nonlinear Phenomena

This paper demonstrates an analytical description of the non-stationary response of the forced Duffing oscillator near the 1:1 resonance. Our approach exploits the concept of the limiting phase trajectories (LPTs). The LPT is understood as a trajectory of the system being initially at rest, and motion over the LPT corresponds to a maximum possible energy transfer from an external source of harmonic excitation to the oscillator. It is shown that for a wide range of parameters the behavior of the Duffing oscillator moving over the LPT is similar to the dynamics of a free particle between two motion-limiters. The vibro-impact hypothesis suggests a perturbation technique based on non-smooth generating functions, which yields an explicit asymptotic expression for the LPT. Different types of the dynamical behavior of the oscillator subjected to harmonic or narrow-band perturbations are studied.

Limiting phase trajectories and non-stationary resonance oscillations of the Duffing oscillator. Part 1. A non-dissipative oscillator

Communications in Nonlinear Science and Numerical Simulation, 2011

This paper demonstrates an analytical description of the non-stationary resonance response of the Duffing system subject to 1:1 resonance. The approximate procedure is based on a recently introduced concept of the limiting phase trajectories (LPTs). The LPT is understood as a trajectory of the system with the initial rest state, and thus corresponds to the most intensive energy transfer from an external source of harmonic excitation to the oscillator. It is shown that the LPT of the Duffing system is similar to the trajectory of a free particle moving between two motion-limiters. The use of special non-smooth transformations gives an explicit asymptotic expression of the LPT of the resonance Duffing oscillators. The theoretical results are confirmed by numerical simulations.

Nonstationary regimes in a Duffing oscillator subject to biharmonic forcing near a primary resonance

Physical Review E, 2011

Analytical investigation of non stationary processes in Duffing oscillator subject to a bi-harmonic forcing, under conditions of a primary resonance is carried out in the present paper. The earlier developed methodology of limiting phase trajectories (LPTs) for studying highly non-stationary regimes, characterized by intense energy exchanges between the different degrees of freedom is successfully applied to the system under investigation. Two distinct types of LPT trajectories are described in the first part of the study. Conditions for the recurrent transitions in time from one type of LPT to another corresponding to the un-damped case were derived. Approximation of the LPT related to the higher amplitude of oscillations was developed using non-smooth transformations. Analysis carried out in the study has revealed the necessary and sufficient conditions for excitation of relaxation oscillations exhibited by a lightly damped system. It was also demonstrated that the mechanism of relaxations may be approximated and explained by the methodology of LPTs, characterized by a strong energy exchanges between the coupled oscillators or alternatively a single oscillator and an external source of energy. The results of analytical approximations and numerical simulations are observed to be in a quite satisfactory agreement.

Creation–annihilation process of limit cycles in the Rayleigh–Duffing oscillator

Nonlinear Dynamics, 2012

The present paper examines the creationannihilation process of limit cycles in the Rayleigh-Duffing oscillator with negative linear damping and negative linear stiffness. It is obtained by the perturbation method, in which the number of limit cycles in the Rayleigh-Duffing oscillator varies with the linear damping and stiffness. Numerical simulations are performed in order to confirm the analytically obtained creation-annihilation process of limit cycles. Moreover, we compare the process of limit cycles in the Rayleigh-Duffing oscillator to that of limit cycles in the van der Pol-Duffing oscillator. The difference in these oscillator is only in nonlinear forces, which causes a qualitative difference in the creationannihilation processes.

Limiting phase trajectories and energy exchange between anharmonic oscillator and external force

Nonlinear Dynamics, 2009

ABSTRACT We present a simple analytical description of transient vibrations of forced anharmonic oscillator in terms of periodic non-smooth functions. Such a description (in chosen variables) is similar to that of a vibro-impact process. The main attention is paid to properties of the limiting phase trajectories (LPTs) describing intensive energy exchange between the oscillator and external force. We show that two dynamical transitions occur in the undamped system under consideration with increasing parameter of nonlinearity. The first transition consists in fast change of slow modulation period and drastic change of amplitude. This transition is characterized by appearance of dynamics resembling vibro-impact behavior in appropriate coordinates (amplitude and phase shift between the oscillator and external force). It corresponds to qualitative transformation of the LPT. The second transition corresponds to annihilation of two stationary points. Numerical study confirms our analytical results.

A new analytical approximation to the Duffing-harmonic oscillator

Chaos, Solitons & Fractals, 2009

In this paper, a novel analytical approximation to the nonlinear Duffing-harmonic oscillator is presented. The variational iteration method (VIM) is used to obtain some accurate analytical results for frequency. The accuracy of the results is excellent in the whole range of oscillation amplitude variations.

Parametrics Resonances of a Forced Modified Rayleigh-Duffing Oscillator

We investigate in this paper the superharmonic and subharmonic resonances of forced modified Rayleigh-Duffing oscillator. We analyse this equation by method of multiple scales and we obtain superharmonic and subharmonic resonances order-two and order-three. We obtain also regions where steady-state subharmonic responses exist. Finally, we use the amplitude-frequency curve for demonstrate the effect of various parameters on the response of the system.

Parameter Influence on the Harmonically Excited Duffing Oscillator

Acta Polytechnica Hungarica, 2014

In this paper the influence of the initial conditions and the interaction of the parameters on the motion of the strong nonlinear Duffing oscillator are investigated. The initial conditions are arbitrary and need not be zero. An analytical procedure for solving the strong nonlinear differential equation with excitation term is developed. The obtained solutions give the physical explanation of the excited vibrations caused by the excitation force and non-zero initial conditions. The analytical results are compared with numerical results and show good agreement.

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