Investigation of vibrations of a multilayered polymeric film

Abstract

Vibrations of a multi – layered polymeric film are investigated numerically by assuming that the film consists from three layers. The upper and lower layers are stiff and do not deform in the transverse direction, while the internal layer can deform in the transverse direction. The first four eigenmodes are analysed, graphical results of their investigation are presented. Experimental investigations of the multi – layered polymeric material PET+PAP+LDPE are performed exciting this material by forced vibrations. By using the method of digital speckle photography the first four eigenmodes are obtained. It is shown that with the increase of excitation frequency the eigenmodes change. The obtained results of numerical investigations are compared with the experimental ones. The obtained results of investigations are applied for the determination of characteristics and qualities of packaging materials.