An experimental method of measuring the quasi-static and dynamic confined behaviour of PMMA

¹ Laboratory of Physics and Mechanics of Materials, Université Paul Verlaine - Metz, Ile du Saulcy, 57045 Metz cedex 1, France
² URCA/GRESPI/LMN, Université de Reims, BP 1039, 51687 Reims cedex 2, France
³ Laboratory of mechanics, Biomechanics, Polymers and Structures (LABPS), National Engineering School of Metz (ENIM), Ile du Saulcy, 57000 Metz cedex 1, France

^a e-mail: pascal.forquin@univ-metz.fr

Abstract

A testing device is presented for the experimental study of the confined behaviour of PMMA in compression under quasi-static loading or at high strain-rates. The constitutive relation of the material ring (allowing to confine the PMMA) being known, transverse gauges glued on its lateral surface allow for the measurement of the lateral confining pressure. The hydrostatic pressure and the Mises stress may be computed. Quasi-static and dynamic tests performed in a strain-rate range of 1e-3/s 1e3/s are processed with the method and compared to results of unconfined compression tests. It is found that the compressive behaviour of PMMA is weakly influenced by the level of pressure and much more sensitive to strain-rate: an elastic brittle behaviour is observed at high strain-rates in unconfined or confined conditions whereas elastoplastic behaviour is noted under quasi-static loading.