On the vibration field correlation of randomly excited flat plate structures, II: Experimental verification

The results of an experimental investigation of vibration field spatial correlation carried out on two flat plate structures and on a car body shell are presented herein. The main purpose of this investigation was to assess the validity of the theoretical spatial correlation model presented in part I of this work [1]. Measurements of vibration acceleration were used as a means of estimating the frequency averaged spatial correlation coefficient of these structures under random excitation. It is observed that for cases of low modal overlap (M < 1) the analytical results are valid as a frequency average estimate in bands in which at least eight to ten modes are excited at resonance. For cases of high modal overlap (M >> 1) the analytical results can be used as a narrow band estimate of the spatial correlation Corrections proposed to account for the effects of mechanical excitation, presence of stiffeners and curvature are shown to be valid. (C) 1998 Academic Press.