Recent zbMATH articles in MSC 70K28https://zbmath.org/atom/cc/70K282024-03-13T18:33:02.981707ZWerkzeugOscillators at resonancehttps://zbmath.org/1528.340352024-03-13T18:33:02.981707Z"Rojas, David"https://zbmath.org/authors/?q=ai:rojas.davidSummary: An oscillator is isochronous if all motions are periodic with a common period. When the system is forced by a time-dependent periodic perturbation with the same period, the dynamics may change drastically and the phenomenon of resonance can appear. In this article we will study which properties the perturbations must fulfil in order to obtain unbounded solutions. We will consider different oscillators, from harmonic to nonlinear generalizations, and we will set out a number of remarks about the concept of auto-parametric resonance.Dynamic effect of the parametric excitation force on an autoparametric vibration absorberhttps://zbmath.org/1528.700262024-03-13T18:33:02.981707Z"Atepor, Lawrence"https://zbmath.org/authors/?q=ai:atepor.lawrence"Akoto, Richard Nii Ayitey"https://zbmath.org/authors/?q=ai:akoto.richard-nii-ayiteySummary: Autoparametric vibration absorber is a machine invented to suppress vibration and has been widely employed in many fields of engineering. Previous works reported by various researchers have shown that dangerous motions, like the full rotation of the pendulum subsystem or chaotic motion, can emerge due to small perturbations of initial conditions or system parameters. To tackle this problem, a new model of the autoparametric vibration absorber with an attached piezoelectric actuator exciter is proposed in this paper. Under the effects of parametric excitation forces produced by the exciter, the vibration absorber will absorb more vibration energy. The dynamic response of the new system is studied analytically using the method of multiple scales and the results validated numerically using the continuation method and detailed bifurcation analysis. The results show that the vibration amplitudes of the subsystems are reduced, the region over which the absorption takes place gets widened and chaotic regions are removed with the introduction of parametric excitation forces in contrast to that of the original model of the autoparametric vibration absorber.