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

Abstract

This paper deals with the dynamic characterisation of plate structures with elliptical orthotropic stiffness properties, using an equivalent thin plate theory using a wave fitting approach. The method consists in projecting the experimentally determined transverse displacement field of a plate on an analytical Green's function of an elliptical orthotropic plate based on Hankel's functions. The error between the projected and measured fields is then minimized, varying the characteristics of the function until an optimal fit is reached. The thus obtained characteristics are the two flexural rigidities defining the elliptical orthotropy of the plate, and the orthotropy angle. This fitting procedure is applied at each Preprint submitted to Elsevier 28 December 2020 frequency, enabling the determination of frequency dependent dynamic material properties. The method is applied to a honeycomb sandwich panel to validate the proposed fitting approach. The identified flexural rigidities are compared to the estimations obtained by means of an analytical model and the IWC (Inhomogeneous Wave Correlation) method assuming three different type of plate characteristics (anisotropic, orthotropic and elliptical orthotropic). For the elliptical orthotropic assumption, consistent results are observed between the methods and the model over a large frequency range (from 1 to 50 kHz).

On the Identification of Orthotropic Elastic Stiffness Using 3D Guided Wavefield Data

“…Among the various wavenumber extraction methods, the matrix pencil decomposition method (MPDM), the estimation of signal parameters via rotation invariant technique (ESPRIT), and the inhomogeneous wave correlation (IWC) method stand out due to their advantages especially for complex wavenumber extraction. These methods were already being intensely used to identify the elastic and damping properties of materials in several studies [ 18 , 28 , 32 ]. MPDM and ESPRIT used singular value decomposition and the eigen-decomposition of the multi-channel covariance matrix, respectively.…”

Three-Dimensional Bending Analysis of Multi-Layered Orthotropic Plates by Two-Dimensional Numerical Model

“…The multi-layered and orthotropic plates are the subject of both numerical and experimental research. The combined experimental and analytical study of multi-layered laminated glass subjected to low-velocity impacts was presented by Wang et al [20], while the experimental determination of material properties in an elliptical orthotropic plate was proposed by Marchetti et al [21]. The method validated subsequently in a honeycomb sandwich panel combined the equivalent thin plate theory with the wave fitting approach.…”