Abstract
We investigate the mechanical response of jammed packings of circulo-lines in two spatial dimensions, interacting via purely repulsive, linear spring forces, as a function of pressure during athermal, quasistatic isotropic compression. The surface of a circulo-line is defined as the collection of points that is equidistant to a line; circulo-lines are composed of a rectangular central shaft with two semicircular end caps. Prior work has shown that the ensemble-averaged shear modulus for jammed disk packings scales as a power law, , with , over a wide range of pressure. For packings of circulo-lines, we also find robust power-law scaling of over the same range of pressure for aspect ratios . However, the power-law scaling exponent –0.9 is much larger than that for jammed disk packings. To understand the origin of this behavior, we decompose into separate contributions from geometrical families, , and from changes in the interparticle contact network, , such that . We show that the shear modulus for low-pressure geometrical families for jammed packings of circulo-lines can both increase and decrease with pressure, whereas the shear modulus for low-pressure geometrical families for jammed disk packings only decreases with pressure. For this reason, the geometrical family contribution is much larger for jammed packings of circulo-lines than for jammed disk packings at finite pressure, causing the increase in the power-law scaling exponent for .
3 More- Received 24 May 2021
- Accepted 6 July 2021
DOI:https://doi.org/10.1103/PhysRevE.104.014901
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