Variable-cell method for stress-controlled jamming of athermal, frictionless grains.
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.
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Kyle C
KC
Smith
Birck Nanotechnology Center and School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
Ishan
I
Srivastava
Birck Nanotechnology Center and School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
Timothy S
TS
Fisher
Engineering Mechanics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India.
Meheboob
M
Alam