Numerical Modelling of Lamb Wave Propagation in 2D Plate Structures

Abstract

Lamb waves are a growing method for the Non-Destructive Testing and Evaluation (NDT&E) and Structural Health Monitoring (SHM) of aerospace vehicles. These guided waves can propagate over large distances and have a strong tendency to interact with damage. Whilst several methods exist for the modelling of Lamb wave propagation, this paper is the first to introduce a first principles  numerical model that can efficiently and accurately predict the behaviour of Lamb waves. The numerical model is easier to understand and implement compared with analytical solutions and significantly faster than discretised numerical methods. The numerical model is presented in detail for an isotropic and homogenous plate, along with validation against the industry accepted, WaveForm Revealer 3 (WFR3) software. The results show a mean correlation across all assessed parameters of 90.4% and 96.6% for the symmetric and antisymmetric modes, respectively. Further discussion is provided on future developments to the model, including on the topic of high temperature effects, anisotropic materials, and edge reflections.