Vibration peculiarity of impacting variable cross section cantilever structure

Abstract

The aim of this study is to obtain information about the influence of cross section changes to dynamic behavior of vibrating beam. It was found that location of the changed cross sections influences energy dissipation in the structure and could be used for damping structural vibrations. The contacting interaction of structure with support is characterized by a rich spectral content of excitation impulses capable to excite a wide range of natural modes. The finite element method is used for the defected beam free vibration analysis. The adequacy of mathematical model to physical one is shown employing developed experimental setup. By providing the first three natural frequencies through vibration simulation, amplitude-frequency characteristics are plotted. The most favorable conditions for energy dissipation in the structure material appear when the frequencies of divided by structural defects parts differ twice because its vibrations are pre-phasic, which excites the higher vibration modes.