Szukana fraza: [Abstract = "The Rayleigh\-Ritz method is used to calculate the frequency parameter for the first two modes of vibration for different values of the structural parameters, i.e. the taper parameter, thermal gradient, aspect ratio and non\-homogeneity constant. Results are obtained for three boundary conditions, i.e. clamped boundary \(C\-C\-C\-C\), simply supported boundary \(SS\-SS\-SS\-SS\) and clamped\-simply supported boundary \(C\-SS\-C\-SS\). Numerical values of the frequency parameter are given in a compact tabular form."]