Experimental measurement and numerical simulation of fundamental anti-symmetrics lamb wave scattering in composites

One critical factor affecting the performance of Lamb wave based damage detection and characterization techniques is the angular amplitude distribution of the interrogating wave scattered at defects and structural features. Analytical solutions for this problem do not exist for composite laminates due to the anisotropic nature and multilayer characteristics of the material. In this paper the scattering characteristics of the fundamental anti-symmetric Lamb wave at delaminations and structural features in composite laminates is considered. Experimental measurements and finite element simulations are employed to quantify the A0 mode Lamb wave scattering characteristics at delaminations and through holes. Good agreement is found between the simulations and experimental measurements. Extended parameter studies provide improved physical insight into the phenomena and show that the angular distributions of the scattered wave amplitudes depend on the defect size to wavelength ratio, the stacking sequence of the laminate and, in the case of delamination damage, the through thickness location of the delamination. © 2011 American Institute of Physics.M. Veidt and C. T. N