Contactless measurement of the elastic Young's modulus of paper by an ultrasonic technique

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 A 0 (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 A 0 measurements. These moduli values were found to be in good agreement with those measured using a common laboratory contact ultrasonic technique.