Pugnaloni Luis A, Carlevaro C Manuel, Kozlowski Ryan, Zheng Hu, Kondic Lou, Socolar Joshua E S
Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de La Pampa, CONICET, Uruguay 151, 6300 Santa Rosa (La Pampa), Argentina.
Instituto de Física de Líquidos y Sistemas Biológicos, CONICET, 59 789, 1900 La Plata, Argentina and Departamento de Ingeniería Mecánica, Universidad Tecnológica Nacional, Facultad Regional La Plata, Avenida 60 Esquina 124, 1900 La Plata, Argentina.
Phys Rev E. 2022 Apr;105(4):L042902. doi: 10.1103/PhysRevE.105.L042902.
Experiments and simulations of an intruder dragged by a spring through a two-dimensional annulus of granular material exhibit robust force fluctuations. At low packing fractions (ϕ<ϕ_{0}), the intruder clears an open channel. Above ϕ_{0}, stick-slip dynamics develop, with an average energy release that is independent of the particle-particle and particle-base friction coefficients but does depend on the width W of the annulus and the diameter D of the intruder. A simple model predicts the dependence of ϕ_{0} on W and D, allowing for a data collapse for the average energy release as a function of ϕ/ϕ_{0}. These results pose challenges for theories of mechanical failure in amorphous materials.
通过弹簧拖拽一个入侵者穿过颗粒材料的二维环形区域所进行的实验和模拟显示出强烈的力波动。在低填充率（ϕ<ϕ₀）时，入侵者会清理出一条开放通道。高于ϕ₀时，会出现粘滑动力学，其平均能量释放与颗粒间和颗粒与基底的摩擦系数无关，但确实取决于环形区域的宽度W和入侵者的直径D。一个简单模型预测了ϕ₀对W和D的依赖性，使得平均能量释放作为ϕ/ϕ₀的函数能够进行数据合并。这些结果对非晶材料的机械失效理论提出了挑战。
