Generalised semi-analytical method for excitability curves calculation and numerical modal amplitude analysis for Lamb waves

The paper presents an efficient and exact method for the calculation of excitability curves and for the analysis of numerical models for guided waves. The proposed procedure makes use of the wave equation and through-thickness-only discretisation of anisotropic, layered plates to obtain the Lamb wave amplitude characteristics. Thereby, the method can be used for any arbitrarily selected anisotropic (layered structures, such as composites) material in a straightforward manner. A general framework for the proposed analysis is given, along with application examples. For this purpose, orthogonality conditions based on the reciprocity theorem are derived for the numerical model. Although the developed mathematical framework is verified and application examples are given based on the local interaction simulation approach for elastic waves propagation, the proposed methodology can easily be adopted for other numerical methods (eg, finite elements and cellular automata for elastodynamics). The method can also be used to study the influence of discretisation parameters on excitability curves estimates.