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

• Published in: Journal of sound and vibration 2021-03, Vol.495, p.115897, Article 115897
• Main Authors: Marchetti, Fabien, Roozen, N.B., Segers, Joost, Ege, Kerem, Kersemans, Mathias, Leclère, Quentin
• Format: Article
• Language: English
• Subjects: Anisotropy; Dynamic equivalent properties; Dynamic equivalents; Elliptical orthotropy; Equivalence; Error analysis; Experimental methods; Experimental validation; Flexural rigidities; Frequency ranges; Green's functions; Material properties; Mathematical functions; Mathematical models; Mechanics; Orthotropic plates; Orthotropy; Physics; Plate theory; Sandwich panels; Stiffness; Thin plates; Vibrations; Wave fitting approach
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1016/j.jsv.2020.115897

•Determination of dynamic equivalent material properties of elliptical orthotropic plates.•Wave fitting approach based on Hankel’s functions.•Application of the experimental methodology on a honeycomb sandwich panel.•Identified flexural rigidities compared to IWC method and an analytical model. 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 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).