Transient mechanics of foams and emulsions

Systems far from equilibrium have numerous practical uses, but challenge our understanding of their underlying physics. Materials like foams, emulsions, suspensions and granular matter can show liquidlike properties or get trapped in a solidlike jammed state. The phase transition between the flowing and static state is often referred to as the ‘jamming transition‘. This work focuses on the mechanical behavior of amorphous viscoelastic materials, close to the jamming point. In many traditional solids, the relation between stress and strain is well described by a linear proportionality, known as Hooke’s law. In jammed solids, by contrast, the stressstrain relation quickly becomes nonlinear, making them much harder to model. Here we ask how and why the linear response breaks. To answer the questions, we investigate the breakdown of linear response as a function of deformation rate and amplitude.