This is the first part of a 2-paper series describing a generalized multi-mechanism
constitutive model for the dynamic failure of quasi-brittle materials (eg, ceramics and
geomaterials), and focus on the poorly understood mechanism of amorphization.
Amorphization has long been recognized as a significant deformation mechanism in a
variety of quasi-brittle materials. In this part, we develop an amorphization model based on
observations in both experiments and atomistic simulations. We consider the onset of …

In Part I, we established a model for amorphization during the failure of quasi-brittle
materials. In this Part II, we present a multi-mechanism physics-based constitutive model
which incorporates amorphization, microcracking and granular flow as basic deformation
mechanisms. With this new integrative model, we investigate the interaction and competition
of the different mechanisms. In the amorphization model we considered the initiation and
evolution of amorphization bands. Microcracking is described with the micromechanics …