%0 Journal Article
%T EFFECTS OF GEOMETRIC RATIOS AND FIBRE ORIENTATION ON THE NATURAL FREQUENCIES OF LAMINATED COMPOSITE PLATES
%A B Attaf
%A M. Bachene
%J Journal of Fundamental and Applied Sciences
%D 2010
%I El Oued University
%X The present investigation aims to examine the influence of geometric ratios and fibre orientation on the natural frequencies of fibre-reinforced laminated composite plates using finite element method based on Yang¡¯s theory and his collaborators. The transverse shear and rotatory inertia effects were taken into consideration in thedeveloped Fortran computer program. It has been shown that the use of first-order displacement field provides the same accuracy as higher-order displacement field when the number of elements representing the plate structure is increased (refined mesh).However, poor precision may appear for plates with high thickness-to-side ratio h/a (thickness/side length). This discrepancy limits the application of the developed theory to thick plates (h/a<0.5). The various curves show the evolution of the dimensionless frequency ( *) versus fibre orientation angle ( ) and illustrate the apparition of a ¡°triple-point¡± phenomenon engendered by the increase of the plate aspect ratio a/b (length/width) for a specific value of h/a. This point defines the maximum naturalfrequency and the associated fibre orientation. Also, results show that for high and/or low aspect ratios, the triple-point phenomenon does not occur. This latter is rapidly reached for thick plates than thin plates when the plate aspect ratio a/b is progressively increased.
%K composite plates
%K dimensionless frequency
%K fibre orientation
%K finite element method
%K geometric ratios
%K triple-point.
%U http://jfas.info/index.php/JFAS/article/view/15/pdf