Accession Number : AD0669294

Title :   VIBRATION MODES AND RANDOM RESPONSE OF A MULTIBAY PANEL SYSTEM USING FINITE ELEMENTS,

Corporate Author : NATIONAL AERONAUTICAL ESTABLISHMENT OTTAWA (ONTARIO)

Personal Author(s) : Lindberg,Garry M. ; Olson,Mervyn D.

Report Date : DEC 1967

Pagination or Media Count : 68

Abstract : A finite element approach to the dynamic analysis of continuous skin-stringer panels is presented. The method is illustrated in the calculation of vibration modes and random response of a five-bay stringer-stiffened panel with all outer edges clamped. The panel skin is represented by finite plate elements and the stringers, which are assumed infinitely stiff in bending, are represented by beam torsional elements. Results are presented for the first 35 panel vibration modes. These modes occur in distinct groups with five similar modes in each, the number five corresponding to the number of panel bays. The response of the panel to plane wave propagation of acoustic noise (propagating normal to the stringers) is also calculated. The resulting response power spectral densities were found to be fundamentally different from those associated with single span panels. These power spectra did not have widely separated peaks, but rather the peaks tended to be squeezed into groups corresponding to the groupings of natural frequencies for the panel. (Author)

Descriptors :   (*PANELS, VIBRATION), RESPONSE, STRESSES, EQUATIONS OF MOTION, TORSION, LOADS(FORCES), CANADA

Subject Categories : Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE