Kim M., Cho C., Cho H., Lee H.

A symmetrical circular cantilever beam with periodic external excitation shows a lot of non-linear responses. A flexible circular cantilever beam has non-linear terms of inertia, spring, and viscosity. Each term represents different characteristic of non-linear response. In lower order modes, the non-linearity due to spring is dominant, while the non-linear effect of inertia is dominant in higher order modes. In the analysis of the response characteristics of a cantilever beam, the jump phenomena in planar and nonplanar directions are analyzed in the analysis of frequency response characteristics. When the non-linear phenomena occur, the superharmonic and subharmonic motions of the beam are analyzed using autospectrum and cepstrum. The phase portrait method is used for the analysis of phase change on the change of excitation frequency. In the analysis, it can be seen that the subharmonic motion plays an important role in causing non-linearity in the beam.