The High-Resolution Wavevector Analysis for the characterization of the dynamic response of composite plates

The High Resolution Wavevector Analysis (HRWA) is presented and its application illustrated. Extending the High Resolution Wavenumber Analysis method [1] to 2D signals, it allows the wide-band and local characterization of the linear elastic behavior of anisotropic plates. The method belongs to the family of experimental wavenumber-based characterization methods and uses the high resolution signal processing algorithm ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques) and the ESTER criterion (ESTimation of ERror) to overcome some of the limitation of Fourier-based methods. Three experimental applications on composite plate specimens are presented. First (i), from the out-of-plane velocity field of a sandwich plate with a foam core, different wave types (bending, shear and compression) are extracted. The results are compared with numerical predictions. Second (ii), individual layer contributions are separated on a honeycomb sandwich plate by means of the observation of the dependence of the extracted complex wavevectors as a function of wave propagation direction and frequency. Third (iii), a local wavenumber extraction is performed on a 4-layer carbon-epoxy plate made of fiber patches with spatially varying orientations. The local specific bending stiffness of the plate is identified from the extracted wavevectors and compared with theoretical results.