抄録
Experimental results are presented on nonlinear vibrations of a plate carrying a concentrated mass with mixed boundary of rectangular and circular shapes. The plate with the mixed boundary is simply supported for deflection. Under periodic lateral excitation, chaotic responses are obtained in a specific frequency region. The chaotic responses are examined with the Fourier spectra and the maximum Lyapunov exponents. Applying the principal component analysis, contribution ratio of each vibration mode is clarified. It is found that chaotic responses of the plate without the concentrated mass are generated from the internal resonant response between the lowest and sixth modes. With the concentrated mass, chaotic responses are generated from the combination resonant response between the lowest and fourth modes of vibration. Increasing the concentrated mass, time variation of contribution ratio corresponding to each vibration mode becomes small.
