ELSEVIER Ultrasonics 37 (1999) 133-139

Mazen Khoury ^a, Guy Eymin Tourtollet ^b, André Schrôder ^c,*

a Laboratory of Paper Science and Graphic Arts at E.FP. G., Domaine Universitaire, 461 rue de la Papeterie, BP 65, 38402 Saint-Martin-d'Hères, Cedex, France

b Centre Technique du Papier, Domaine Universitaire, BP 251, 38044, Grenoble, Cedex 9, France

c Elf-Atochem, UMR CNRS no.167, Systèmes Macromoléculaires Hétérogènes, 95 rue Danton, BP 108, 92303 Levallois Perret, Cede-~, France

Received 19 November 1997; received in revised form 3 September 1998

Abstract The use of a non-contact ultrasonic technique for the characterization of the in-plane elastic Young's moduli of paper is considered. The determination of these moduli from Ao (fundamental antisymmetric plate wave mode) measurements, using the empirical technique introduced by Luukkala et al. (1971), is discussed: it is shown that the common low frequency approximation is not valid for paper, owing to its orthotropic structure, Numerical simulations are used to evaluate the validity domain of . Luukkala's method. A new device was developed, and Young's moduli of various paper sheets were determined from Ao measurements. These moduli values were found to be in good agreement with those measured using a common laboratory contact ultrasonic technique.

@ 1999 Elsevier Science B. v. Al! rights reserved. Keywords: Elastic moduli; Paper; Plate waves; Tensile strength; Ultrasonic materials testing