Robust 2D-Spatial Fourier Transform Identification of Wavenumber-Space Characteristics of a Composite Plate

Abstract

This paper addresses the issue of wave propagation features in a honeycomb sandwich plate over a broadband frequency range. The special emphasis putted on such materials is due to their growing industrial integration resulting from interesting mechanical and material properties, such as high energy dissipation and resistance/weight ratio. A two-dimensional spatial Discrete Fourier Transform (2D-DFT) is employed with experimentally measured displacement field, as primary input, to identify a complete wave propagation direction-dependent dispersion equation of the sandwich plate. Valuable insights into the wavenumber-space (k-space) profiles, in relation with the structural orthotropic behavior, are highlighted. The 2D-DFT method is proved to be efficient in a deterministic framework. Nevertheless, its robustness against input parameters’ uncertainty needs to be evaluated as well to achieve more realistic k-space characteristics’ identification. The impact of measurement points’ localization’s uncertainty on the 2D-DFT identifications is statistically investigated. The obtained results show the large variability of the identified k-space parameters and reveal the important identification sensitivity to such measuring errors involved in the experimental manipulations.