Observation of shear jamming in open-cell foams under compression

Past study of non-Newtonian flow through flexible porous media suggests that the augmented compressive stress response of these composite materials arises from the shear thickening of the suspending medium, though the literature does not distinguish between thickening and jamming. Being able to distinguish shear jamming from shear thickening in the bulk of a material under dynamic compression has historically been challenging; in this work, we impact flexible open-cell foams filled with a transparent shear thickening suspension and observe the rheological transitions in the suspending medium through its effects on the foam structure using high-speed video. We show that shear jamming is the dominant contribution to the stress response of this system, as supported by high-speed PIV, stress-strain measurements, and parallel-plate rheology.