Identification of local stiffness reduction is a challenging problem for many engineering materials and structures. The aim of this study is to investigate the potential of guided wave tomography to quantify the stiffness of an isotropic plate. Full-waveform inversion based on acoustic model is applied to estimate the Young’s modulus from the velocity field data of an elastic model. Finite element simulations were carried out to obtain the signals of a guided mode propagating through various stiffness defects in a plate. The inversion results have demonstrated accurate determination of an averaged through-thickness stiffness loss of the waveguide. These results can be exploited further to improve the characterization of stiffness damage in composite structures
