The scattering matrices of Lamb waves at multiple delaminations and broken laminates

Explicit expressions of the scattering matrices of multimodal Lamb waves at multiple horizontal delaminations and broken laminates are derived to characterize the scattering fields when the delamination tips or broken sections keep in alignment vertical to the plate surfaces and mode matching is implemented along the alignment line. The scattering fields of the s0 mode at a broken laminate with different depths in a plate are specially investigated to evaluate the formulation convergence and effectiveness. It is shown with a proper truncation of the infinite Lamb modes, the calculation results show good convergence to conserve the energy flux and the obtained scattering coefficients are in good accordance with those obtained by numerical simulation.

► Explicit formulas of the scattering matrices of Lamb waves at multiple delaminations and broken laminates.
► Semi-analytical method based on the modal decomposition technique.