Schreck Carl F, Hoy Robert S, Shattuck Mark D, O'Hern Corey S
Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut 06520-8260, USA and Department of Physics, Yale University, New Haven, Connecticut 06520-8120, USA.
Department of Physics, University of South Florida, Tampa, Florida 33620, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2013 Nov;88(5):052205. doi: 10.1103/PhysRevE.88.052205. Epub 2013 Nov 25.
We perform numerical simulations of repulsive, frictionless athermal disks in two and three spatial dimensions undergoing cyclic quasistatic simple shear to investigate particle-scale reversible motion. We identify three classes of steady-state dynamics as a function of packing fraction φ and maximum strain amplitude per cycle γ(max). Point-reversible states, where particles do not collide and exactly retrace their intracycle trajectories, occur at low φ and γ(max). Particles in loop-reversible states undergo numerous collisions and execute complex trajectories but return to their initial positions at the end of each cycle. For sufficiently large φ and γ(max), systems display irreversible dynamics with nonzero self-diffusion. Loop-reversible dynamics enables the reliable preparation of configurations with specified structural and mechanical properties over a broad range of φ.
我们对二维和三维空间中经历循环准静态简单剪切的排斥性、无摩擦、非热盘进行了数值模拟，以研究粒子尺度的可逆运动。我们根据填充率φ和每个循环的最大应变幅度γ(max)确定了三类稳态动力学。点可逆状态下，粒子不发生碰撞且精确回溯其循环内轨迹，这种状态出现在低φ和γ(max)时。处于环可逆状态的粒子会经历多次碰撞并执行复杂轨迹，但在每个循环结束时会回到其初始位置。对于足够大的φ和γ(max)，系统呈现出具有非零自扩散的不可逆动力学。环可逆动力学能够在广泛的φ范围内可靠地制备具有特定结构和力学性能的构型。
