The article presents a method of damage identification in composite rods and beams based on the analysis of changes in Lamb wave propagation. For modelling of the problem the spectral element method is used. Spectral elements of rod and beam suitable for modelling the composites are employed. In the presented paper the following discontinuities are analysed: the fatigue open and not propagating crack, changes in the cross-section area, material discontinuities, various fibres volume and angle. The influence of discontinuities on the Lamb wave propagation processes is analysed.