The Effects Of Large Vibration Amplitudes On The Mode Shapes And Natural Frequencies Of Thin Elastic Structures, Part III: Fully Clamped Rectangular Isotropic Plates—Measurements Of The Mode Shape Amplitude Dependence And The Spatial Distribution Of Harmonic Distortion

Abstract In this work, the amplitude dependence of the resonance frequency and the spatial distribution of the first and second harmonic components of the dynamic response of a fully clamped rectangular homogeneous plate have been investigated experimentally. By using electrodynamic point excitation at the centre of the plate and a non-contacting optical vibration transducer for response measurement, the spatial distribution of the complex harmonic distortion has been investigated. In order to reach high amplitudes of vibration under distributed loading, a set of tests were also carried out with a progressive wave tunnel, in which the plates tested were subjected to high level acoustic excitation at overall sound pressure levels up to 155 dB. The results of such experimental measurements are given and compared with theoretical predictions.