Comparison and parametric study of characteristics of eleven types of anisotropic woods based on the behaviour of Lamb wave propagation

Knowledge in advance of the nine orthotropic independent elastic constants (Cij) of the wood medium is essential for evaluating its mechanical properties. The most prominent technique to retrieve Cij is the ultrasonic testing technique. This technique uses guided waves that can propagate through the material under test. Accordingly, it is worth noting that the numerical modelling of the phase and group velocities of guided waves is an unavoidable preliminary step before experimentally producing guided wave modes. Therefore, the main goal of the present work is to numerically calculate the phase velocity, group velocity and the relevant optimal incidence angles of Lamb waves in anisotropic wood that can be used as a numerical parametric study for any future experimental setup. Here, Lamb dispersion curves are calculated for eleven types of woods, where the Legendre polynomial method is employed to solve the wave equations. Moreover, the optimal incidence angle for each Lamb mode is calculated according to the Snell-Descartes law. By calculating out the three parameters of phase velocity, group velocity and optimal incidence angle of Lamb modes in eleven types of anisotropic woods, we hope to fast-track the researchers in considering the present work to facilitate their experimental measurements.