Stationary and nonstationary four — frequency analisis forced vibrations of thin elastic shell with initial deformations

K. Hedrih ; R. Pavlović ; P. Kozić ; S. Mitić

Theoretical and applied mechanics, Tome 12 (1986) no. 1, p. 33 .

Résumé

The stationary resonant regimes under conditions of effect a four-frequency force, was studied by means of the system differential equations of the first approximation for amplitude and phase of the four-frequency regime of a nonlinear vibrations of the thin elastic shell with a initial deformities. By means of numerical results, the families amplitude-frequency curves of the stationary resonant state for the first four forced harmonics, was composed. At the amplitude-frequency curves one can be see the existence a number of the resonant jumps. By means of the systems differential equations of the first approximations for amplitude and phase of the four-frequency regime of the nonlinear vibrations of thin elastic shell with a initial deformations, unstationary resonant regimes have studied, under conditions of effect of the four-frequent forced vibrations that are a slow changeable functions of the time in comparisons with a natural unit of time for a coresponding undisturbed system. By means of numerical results, families of the curves of the amplitude frequency ustacionary resonant state for the first four incentived harmonics. From amplitude-frequency curves one can be seen that they corespond to the amplitude-frequency of a stationary resonant state and they are move near each another for a more litle speeds change of a frequencies of a forced powers.