Compactivity and transmission of stress in granular materials.
Compactivity and transmission of stress in granular materials.
复制标题
颗粒材料的压实度和应力传递。
作者：
S. Edwards;D. Grinev
我们概述了颗粒材料的统计力学理论。静态颗粒介质中的应力传播和力波动仍然知之甚少。我们发展了提供应力平衡基本方程的统计力学理论。形式主义是基于这样的假设，即颗粒是刚性的、无粘结性的，摩擦是完美的。由于假设颗粒是完全刚性的，任何应变场或位移场都不能进入应力场的静态平衡方程。给出了材料的几何规格，从晶间力方程和扭矩平衡方程导出了完整的应力张量方程组。这些新的本构方程确实是基本的，它们基于材料内部应力张量的各个分量之间的关系，并取决于颗粒堆积的拓扑结构。考虑了将“无张力”约束纳入形式主义的问题。回顾了压实度的概念。讨论了压实度概念与应力传递问题之间的关系。(C)1999年美国物理研究所。
We outline a statistical-mechanical theory of granular materials. Stress propagation and force fluctuations in static granular media are still poorly understood. We develop the statistical-mechanical theory that delivers the fundamental equations of stress equilibrium. The formalism is based on the assumptions that grains are rigid, cohesionless, and that friction is perfect. Since grains are assumed perfectly rigid, no strain or displacement field can enter the equations for static equilibrium of the stress field. The complete system of equations for the stress tensor is derived from the equations of intergranular force and torque balance, given the geometric specification of the material. These new constitutive equations are indeed fundamental and are based on relations between various components of the stress tensor within the material, and depend on the topology of the granular packing. The problem of incorporating into the formalism the "no tensile forces" constraint is considered. The compactivity concept is reviewed. We discuss the relation between the concept of compactivity and the problem of stress transmission. (c) 1999 American Institute of Physics.