Structural basis for the yield stress in plastic disperse systems

The apparent yield stress is a fundamental rheological characteristic of a plastic material. In this work, we propose a model that relates the structure of a fractal particle network to its yield stress. The model predicts the yield stress to be a function of particle size, solid-liquid surface free energy, the amount of network material, and the fractal dimension of the network. The predicted yield stress corresponded to the stress at the limit of linearity in fat crystal networks. Moreover, a structural definition for the yield stress is proposed.