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

Abstract

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.

Experimental methodology to assess the dynamic equivalent stiffness properties of elliptical orthotropic plates

“…The distribution of these resonators logically generates a strong and distributed damping effect, explaining the observed attenuation. Such effect can be related to the singularity observed by Margerit et al [23] around 34 kHz on a similar honeycomb sandwich (of around 5 mm of thickness) for both real and imaginary parts of the identified complex wavenumbers 2 . A second effect can be observed at high wavenumbers.…”

“…Note that, in[23], the acoustic phenomenon (c 0 /(2h)) coincides in frequency with the resonance of the cells (half-wavelength π/k around the cell size (≈ 7 mm)…”

An INverse COnvolution MEthod for wavenumber extraction (INCOME): Formulations and applications

“…The ESPRIT algorithm works in the 1D case and can be applied to the 2D case if the signal of interest can be approximated as the sum of a small number of plane waves. In some cases, the second condition can be artificially forced by partitioning the initial domain of measurement into several subdomains [11].…”

Prediction of frequency and spatially dependent attenuation of guided waves propagating in mounted and unmounted A380 parts made up of anisotropic viscoelastic composite laminates

“…11,37 Besides, two advanced identification methods are also used, including the matrix pencil method 16 and the estimation of signal parameters via rotational invariance techniques. 38 The common characteristic of both methods lies in that they can identify not only the attenuation coefficient but also the propagating wavenumber.…”