Modal Expansion of Structural Intensity for Flexural Vibration on Plates

Abstract

This paper presents modal descriptions of structural intensity for flexural vibration on flat plate. The modal forms of the structural intensity are expressed by superposition of the product of weight coefficient and cross-modal function which can be estimated by two natural modes. The characteristics of the weight coefficients and the cross-modal functions are discussed by using numerical analysis. It is shown that the cross-modal functions can be classified into two types of distributions-power transmission and non power transmission types-. It is also shown that the non power transmission type cross-modal function can take no propagating power. At last we demonstrate that the derived modal form of the intensity can be useful to explain the difference of the structural intensity under two different excitation frequencies. The demonstration would suggest that the modal expansion can be effective for designing the structural intensity distribution.