COMPUTATION OF PROPAGATIVE WAVES IN FREE RAIL USING A FINITE-ELEMENT TECHNIQUE

A method is presented for the numerical computation of the wavenumbers and associated modes of the cross-section of solid waveguides. The method, based on the finite element technique, is well suited to the computation of both the propagative and the evanescent waves in a straight waveguide with an arbitrary cross-section. The solution is obtained by factorization, with the cross-section of the waveguide being modelled by numerical discretization. The dispersion curves of propagative waves in a free rail are computed by using triangular and quadrilateral ''finite elements of the cross-section''. The evolution of cross-section modes as the frequency increases is evaluated and discussed. (C) 1995 Academic Press Limited