Rigidity and Packing in SeSP Dispersions

We use athermal molecular dynamics simulations to study coupling, entanglement, and rigidity in dispersions of Superellipse Sector Particles (SeSPs) above and below jamming. SeSPs are segments of superelliptical curves, forming a tunable set of hard-particle shapes that exhibit complicated coupling between particle position, orientation, and separation. We use constraint counting to identify rigid clusters of particles and determine the rigidity percolation point, as well as an upper bound for random loose packing and a lower bound for random close packing. We systematically vary SeSP angularity and opening angle to investigate the impact on critical packing fractions and correlations with local-to-intermediate scale structure. We find that the random close packing fraction varies non-monotonically with angularity, unlike the random loose packing fraction, which decreases monotonically.