Characterization of Guided-wave Propagation in Composite Plates

The increasing use of composite materials in multiple engineering applications has emphasized the need for structural health monitoring (SHM) technologies capable of detecting, locating, and classifying structural defects in these materials. Guided wave (GW) methods offer an attractive solution for SHM due to their tunable sensitivity to different defects and their ability to interrogate large structural surfaces. The complications associated with the material anisotropy and directionality in composites result in an increased need for accurate and efficient simulation tools to characterize GW excitation and propagation in these materials. This paper presents a theoretical model based on three-dimensional elasticity to characterize GW excitation by finite-dimensional transducers in composite laminates. The theory uses an eigenbasis expansion for a bulk transversely isotropic material combined with Fourier transforms, the global matrix approach, and residue theory to find the displacement field excited by an arbitrarily shaped finite-dimensional transducer. Experimental results obtained in a cross-ply composite laminate are used to assess the accuracy of the theoretical solution.