Benchmarking of Methods for the Identification of Flexural Wavenumbers in Wooden Plates

laminated wood panels. Laboratory measurements are performed on a plywood panel, an inhomogeneous and orthotropic plate, and the propagation characteristics of flexural waves are characterized along five radial directions. The methods considered for the analysis are the inhomogeneous wave correlation method, the Prony method and the Time-of-Flight (ToF) method. The first two methods are implemented using the same data: a dense line of points obtained with a scanning Laser Doppler Vibrometer (LDV) and a piezoelectric transducer as an exciter. The ToF method uses a different data set, gathered using four accelerometers and an instrumented impact hammer. The results show a remarkable match between the first two methods, while the third method requires a precise time-domain filtering operation to provide accurate results. Nevertheless, the third method provides a simple and low-cost alternative to the use of the LDV that can be more suited to in situ measurements. The accuracy limits of each method, especially in terms of targeted frequency bandwidth are discussed.