More details about the interaction of forced and parametric resonances arising from in-plane excitation of imperfect rectangular plates

The goal of the present paper is to improve our understanding of the respon se of the in-plane loaded rectangular plates containing initial geometric i mperfection. Besides the frequency responses and FFT curves, which were use d as diagnostic tools in previous investigations, the temporal response and the phase diagram have been added to better study the transition zones bet ween two kinds of vibration modes. The phase portrait shows that the plate response has a number of "unusual and perhaps chaotic" characteristics in t he transition from one mechanism of vibration of another, which distinguish ed it from the more classical periodic response. Moreover, the effect of on e particular spatial mode of imperfection on a different mode of vibration has been investigated for the first time. It was found that the maximum amp litude of forced vibrations is large when vibration and imperfection are in the same mode while the first mode of vibration is always excited whatever the mode of imperfection is. (C) 2001 Academic Press.