Intersections of Lamb Mode Dispersion Curves for an Isotropic Plate

Abstract

In this thesis we discuss the points of intersection of the symmetric and antisym metric Lamb mode dispersion curves of an isotropic plate. The Rayleigh-Lamb frequency relation for dispersion curves is derived for a plate with thickness 2h and their intersections are determined. The points of intersection are graphically represented. The plateau region possessed by the Lamb modes in k-c plane is graphically shown for an isotropic plate where k is the wave number and c is the wave speed. Lastly, the reflection of SV-waves is mathematically examined and the mode conversion through this reflection is discussed analytically. An expression is derived which gives the bound in which mode conversion can take place and outside which it is forbidden.