Author(s)

T.F. Guo & K.C. Hwang

Abstract

A micromechanics based continuum model, taking into account both di- latation and shear strain, is used to study the softening instability behavior of zirconia-toughened ceramics, such as the experimentally observed burst- like or autocatalytic transformation which is associated with a load drop. For a set of constitutive parameters, two deformation modes are examined, namely the onset of localization and the early exhaustion of transformation. The former arises traditionally as an indicator of bifurcations from homo- geneous deformation to localized one, while the latter is here referred as to an indicator of elastic unloadings under continuously increasing straining. Predictions of these two deformation modes on biaxially stretched sheets are shown to be strongly dependent upon the transformation-induced shear strain

Keywords