Softening and Irreversibility in Jammed Solids

Materials like foams and emulsions display complex rhelogical behavior close to their jamming transition. When driven too hard the initial linear stress-strain response breaks down and the material softens. Using simulations of soft repulsive spheres, we characterize the softening crossover by establishing the relevant strain scale below which linear response is valid. We further perform shear reversal tests to investigate the interplay between proximity to jamming and the onset of irreversibility.