NUMERICAL DISPERSION OF HIGHER-ORDER NODAL ELEMENTS IN THE FINITE-ELEMENT METHOD

The discretization inherent in the finite-element method results in nu merical dispersion, In this work, this dispersion is investigated for a time-harmonic plane wave propagating through an infinite, two-dimens ional, finite-element mesh composed of uniform quadrilateral and trian gular elements. The effects on the dispersion due to the propagation d irection of the wave, the order of the elements, the node density, and the mesh geometry are studied. Results are given which can serve as a guide in selecting the appropriate element order, node density, and m esh geometry when applying the finite-element method.