Vibrations Excited by Statistically Fluctuating Forces

Quenching of self-excited vibrations

Stable normal-mode vibrations in engineering can be undesirable and one of the possibilities for quenching these is by embedding the oscillator in an autoparametric system by coupling to a damped oscillator. There exists the possibility of destabilizing the undesirable vibrations by a suitable tuning and choice of nonlinear coupling parameters. An additional feature is that, to make the quenchi...

Modeling of Compressor Shell Vibrations Excited by a Rotor Imbalance

Dressed basis for highly excited molecular vibrations

Starting from a multiresonance spectroscopic Hamiltonian fit by Baggott to experimental levels of H2O, an approximate Hamiltonian is devised using a prediagonalized ‘‘dressed’’ zero-order basis, within which a residual, effective single-resonance coupling operator acts. The dressed basis incorporates many of the effects of nonintegrability, while the effective resonance furnishes much of the si...

Identifying Self-excited Vibrations with Evolutionary Computing

This study uses differential evolution to identify the coefficients of second-order differential equations of self-excited vibrations from a time signal. The motivation is found in the ample occurrence of this vibration type in engineering and physics, in particu lar in the real -life problem of v ibrations of hydraulic structure gates. In the proposed method, an equation structure is assumed a...

Self-excited Lateral Vibrations of Rolling Tires

In this study, a low degree-of-freedom mechanical model of a rolling tire is constructed, in which the lateral deformation of the contact patch and tire carcass is considered. The so-called delayed contact patch model is implemented and combined with a simple tire carcass model. The interaction between the contact patch and the carcass together with the lateral mode of the attached suspension s...