Modelling elastic wave propagation in thin plates

In this work we propose an in-depth study of elastic wave propagation in thin plates. We show that at the frequency range of interest and for modest plate thicknesses, the only waves that can be excited and propagate in the structure are guided waves (also called Lamb waves). This propagation modeling approach is based on the theory of Viktorov. The elastic properties of the panel and the finger touch signature are usually unknown, therefore we propose a method for estimating them through a simple experimental procedure. The obtained estimates are then used to simulate the propagation in the boards. Our approach is to implement the general solution of the elastic wave equation for infinite plates, and introduce the boundary conditions afterwards using a real-time beam tracer. We finally prove the effectiveness of the approach by comparing the predicted response of a finger touch with the measured one on materials such as MDF (Medium Density Fiberboard) and PLX (Plexiglass).