Manevich, A.I.Kołakowski, Z.2021-01-112021-01-112003Manevich A.I., Kołakowski Z., Interaction of global and local modes at free oscillations of compressed thin-walled beams. W: X Sympozjum Stateczności Konstrukcji, Zakopane, 8-12 września 2003, Kowal-Michalska K. (red.), Kołakowski Z. (red.), Wydawca Katedra Wytrzymałości Materiałów i Konstrukcji - Politechnika Łódzka, Łódź 2003, s.275-282, ISBN 83-914019-2-8.83-914019-2-8http://hdl.handle.net/11652/3170The influence of a compressive force on free nonlinear oscillation of thin-walled members is studied. The case of internal autoparametric resonance is considered when the ratio of natural frequencies of global and local modes is close to 2: 1. It is shown that in a vicinity of this resonance the oscillations become amplitudefrequency modulated due to the energy exchange between linear modes. Two coupled stationary oscillation modes exist (which can be regarded as synchronized vibrations in overall and local mode). A bifurcational value of the energy is established after exceeding of which the uncoupled oscillation in overall mode becomes unstable, and stationary modes can be only coupled.encienkościenne elementymetoda wieloskalowasiła ściskającathin-walled membersmultiple scales methodcompressive forceInteraction of global and local modes at free oscillations of compressed thin-walled beamsartykuł