The results of experimental and numerical studies of the peculiarities of dynamics of hemispherical shells made of polymer materials and composites under pulsed (explosive) loading are considered. Unpredictable low-frequency oscillations are excited during the process of elastic vibrations of shells having a free edge, along with modes conforming to an analytical solution of the problem of vibrations of a viscoelastic hemispherical shell. The problem was solved within the framework of general theory of thin shells of Kirchhoff ? Love. «Anomalous» oscillations are characterized by sinusoidal azimuth distribution of the strain amplitude and by a rise in frequency when increasing the shell thickness. The results of the experiments make it possible to correlate a process of low-frequency oscillations in viscoelastic hemispherical shells with the propagation of symmetrical Lamb waves in plates.
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