Investigating Mode Coupling Effects in Composite Beams with Delamination Damage

This project investigates mode coupling effects in laminated composite beams with delamination damage. 8-ply composite beams from carbon fibre woven fabric and different configurations of artificial delamination damage are used in the study. A 3-D explicit finite element simulation modelling the woven layers as transversely isotropic materials are developed to analyse the propagation and scattering behaviour of the fundamental anti-symmetric Lamb wave mode (A0). The results from the 3-D numerical model were in good agreement with analytical solutions derived from the Timoshenko beam theory in terms of phase velocities of the A0 mode. Reflection and transmission coefficient spectrums of two delamination sizes were generated based on the 3-D numerical model. The reflection and transmission spectrums were found to be dependent on the location of measurement points being selected due to the fact that the amplitude of incident wave varies periodically along the length of the beam as well as the width. The wave amplitudes across the width of the beam should also be considered in order to obtain more stable reflection and transmission coefficient spectrums.