Vibration localization in plates rib-stiffened in two orthogonal directions

This study deals with the vibration localization in plates rib-stiffened in two orthogonal directions. The effect of small misplacements of stiffeners, with various combinations of flexural and torsional rigidities, on both the free vibration modes and forced vibration responses of a plate clamped at four edges is presented. An extended finite strip approach, or the compound strip method, is employed to obtain the natural frequencies and the corresponding vibration modes. Galerkin's method is applied to determine the forced vibration response of the rib-stiffened plate subjected to a harmonic concentrated load at the center of one of its four panels. It is observed that a small disorder of the rib-stiffeners may significantly affect the vibration localization of the whole plate. By deliberately introducing irregularity into the stiffeners, the vibration magnitudes of some of the panels of the plate may be reduced.