David R. Owen
Department of Mathematical Sciences
Carnegie Mellon University
Pittsburgh, PA 15213
USA
fax: (1)-412-268-6380
e-mail: do04@andrew.cmu.edu
ABSTRACT:
An energetic description of the hardening behavior of single crystals undergoing single slip is analyzed in this paper. Simultaneous macroscopic simple shear and mesoscopic slips are described by means of recently proposed measures of separation of the active slip bands and of the number of lattice cells trasversed during slips. Nonclassical structured deformations in the form of two-level shears are employed to identify these measures. The energetics of two-level shears gives rise to a response consistent with the experimentally observed loading and unloading behavior of a single crystal in G. I. Taylor's soft devide, as well as with the Portevin-le Chatelier effect. The critical resolved shear stress and the hardening response are obtained, and an application to aluminum single crystals is discussed.