Recent developments on yield stress materials

Abstract

<h2>Abstract</h2> Several gels, suspensions, emulsions and foams found both in nature and industrial processes and products are complex yield stress materials that exhibit a rich variety of mechanical responses, like elasticity and time-dependence, in addition to yielding. A rigorous definition and physical interpretation of the related material functions are challenging. In this talk we discuss how this complexity affects fundamental concepts and measurements of these materials. Our discussion covers different related topics, such as (i) the need for the introduction of a yield stress tensor, (ii) thixotropy modeling---including the choice of the microstructure destruction agent, (iii) rheological characterization with quasilinear large amplitude oscillatory shear, and (iv) transient and steady-state shear banding.