A parametric study of vibration of rotating pre-twisted and tapered low aspect ratio cantilever plates

Abstract

A finite element technique has been used to determine the natural frequencies of a pre-twisted and tapered plate mounted on the periphery of a rotating disc. The pre-twisted plate has been idealized as an assemblage of three noded triangular shell elements with six degrees of freedom at each node. In the analysis the initial stress effect (geometric stiffness) and other rotational effects except the Coriolis acceleration effect have been included. The eigenvalues have been extracted by using a simultaneous iteration technique. Computation of frequencies has been carried out for plates of aspect ratios 1 and 2. Other parameters considered are pre-twist, taper, skew angle and disc radius. From the results of computations an extension to the existing empirical formulae derived by Dokainiah and Rawtani [1] has been suggested for computing natural frequencies of rotating pre-twisted and tapered cantilever plates.