ABSTRACT
The Rayleigh-Ritz method is used to obtain the approximate natural frequencies and the natural modes of a structure. In this method, an approximate expression for the deflection of the structure is assumed that satisfies at least the geometric boundary conditions of the structure. This approximate deflection is used to obtain the maximum values of the potential and kinetic energies. In a conservative system, the maximum potential energy must equal the maximum kinetic energy. In the Rayleigh-Ritz method, the approximate deflection expression is assumed in the form of a linear combination of several expressions, each of which satisfies at least the geometric boundary conditions of the structure. Response to periodic excitation can be obtained by following the same procedure as in the case of sinusoidal excitation. Periodic force is expressed in the form of a Fourier series and the responses to each of the terms are summed together.
