Bifurcation in a Nonlinear Autoparametric System Using Experimental and Numerical Investigations
نویسندگان
چکیده
Experimental and numerical investigations are carried out on an autoparametric system consisting of a composite pendulum attached to a harmonically base excited mass-spring subsystem. The dynamic behavior of such a mechanical system is governedby a set of coupled nonlinear equations with periodic parameters. Particular attention is paid to the dynamic behavior of the pendulum. The periodic doubling bifurcation of the pendulum is determined from the semi-trivial solution of the linearized equations using two methods: a trigonometric approximation of the solution and a symbolic computation of the Floquet transition matrix based on Chebyshev polynominal expansions. The set of nonlinear differential equations is also integrated with respect to time using a finite difference scheme and the motion of the pendulum is analyzed via phase-plane portraits and Poincare maps. The predicted results are experimentally validated through an experimental set-up equipped with an optoelectronic set sensor that is used to measure the angular displacementof the pendulum. Period doublingand chaotic motions are observed.
منابع مشابه
Vibration and Bifurcation Analysis of a Nonlinear Damped Mass Grounded System
In this paper, vibrations and bifurcation of a damped system consists of a mass grounded by linear and nonlinear springs and a nonlinear damper is studied. Nonlinear equation of motion is derived using Newton’s equations. Approximate analytical solutions are obtained using multiple time scales (MTS) method. For free vibration, the approximate analytical results are compared with the numerical i...
متن کاملPost-critical Behavior of Three- dimensional Composite Beams Near the Autoparametric Resonance under Flapwise Excitation
The bifurcation analysis of a composite beam subjected to harmonic flapwise base excitation is studied when the ratio of flapwise and chordwise internal resonances is 1:2. Results are obtained by the numerical solution of modulation equations. Chracteristics of the response are investigated in terms of time history, phase portraits diagrams and bifurcation diagram of poincare maps. It is observ...
متن کاملDynamics of an Autoparametric Pendulum-Like System with a Nonlinear Semiactive Suspension
This paper presents vibration analysis of an autoparametric pendulum-like mechanism subjected to harmonic excitation. To improve dynamics and control motions, a new suspension composed of a semiactive magnetorheological damper and a nonlinear spring is applied. The influence of essential parameters such as the nonlinear damping or stiffness on vibration, near the main parametric resonance regio...
متن کاملDynamical SyStemS with PerioDic coefficientS: analySiS anD control
A general framework for the analysis and control of parametrically excited linear/nonlinear dynamical systems is presented. This class of problems appears in the modeling of rotorcraft blades in forward flight, asymmetric rotor-bearing systems, automotive components such as connecting rods, universal joints, asymmetric satellites, fluids under gravity modulations, etc. These dynamical systems a...
متن کاملNonlinear dynamic analysis of a four-bar mechanism having revolute joint with clearance
In general, joints are assumed without clearance in the dynamic analysis of multi-body echanical systems. When joint clearance is considered, the mechanism obtains two uncontrollable degrees of freedom and hence the dynamic response considerably changes. The joints’ clearances are the main sources of vibrations and noise due to the impact of the coupling parts in the joints. Therefore, the syst...
متن کامل