Abstract

A method is introduced to simulate jamming of polyhedral grains under controlled stress that incorporates global degrees of freedom through the metric tensor of a periodic cell containing grains. Jamming under hydrostatic (isotropic) stress and athermal conditions leads to a precise definition of the ideal jamming point at zero shear stress. The structures of tetrahedra jammed hydrostatically exhibit less translational order and lower jamming-point density than previously described maximally random jammed hard tetrahedra. Under the same conditions, cubes jam with negligible nematic order. Grains with octahedral symmetry having s > 0.5 (where s interpolates from octahedra [s = 0] to cubes [s = 1]) jam with an abundance of face-face contacts in the absence of nematic order. For sufficiently large face-face contact number, percolating clusters form that span the entire simulation box. The response of hydrostatically jammed tetrahedra and cubes to shear-stress perturbation is also demonstrated with the variable-cell method.

Comments

This is the publisher PDF of Smith, KC; Srivastava, I; Fisher, TS; Alam, M. "Variable-cell method for stress-controlled jamming of athermal, frictionless grains." Physical Review E, 89: 042203. 2014. Copyright APS, available at http://dx.doi.org/10.1103/PhysRevE.89.042203.

Keywords

MOLECULAR-DYNAMICS, ZERO-TEMPERATURE, CRYSTALLINE, PACKINGS, TRANSITIONS, DISORDER, BEHAVIOR, SYSTEM, ORDER, SHAPE

Citation

10.1103/PhysRevE.89.042203

Date of this Version

4-4-2014

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