Stress-Strain Behavior of Media Composed of Multi-Sized Granules

本研究的目的是从细观结构的角度研究散体材料的力学行为，得到其应力应变关系。这项研究的重点是建立大应变问题的连续表示的应力-应变关系，其中将特别注意对颗粒系统行为的基本理解，如能量耗散、应力-剪胀特性等。这一目标将通过根据接触力和微观几何测量重新定义连续统变量、应力和应变来实现。考虑颗粒的滑动和旋转，建立了应力应变关系。然后，该理论将扩展到由多个大小的非球形颗粒组成的拾取。将进行棒材组件的实验研究和计算机模拟，以帮助理论的发展。实验研究和计算机模拟的结果以及天然颗粒系统(如沙子)研究的可用数据将用于验证所开发的理论。

The objective of this research is to study the mechanics of granular material from micro-structural point view to obtain the stress-strain relationship. The focus of this research is to formulate the stress-strain relationship for large strain problems with a continuum representation which will be studied with particular attention to the fundamental understanding of the behavior of granular systems, such as energy dissipation, stress- dilatancy characterists, etc.. The objective will be achieved by redefining the continuum variables, stress and strain, in terms of contact forces and micro geometrical measures. The stress-strain relationship will be developed by considering the sliding, and rotation of the particles. The theory will be then extended for pickings made of multi-sized and non-spherical shape particles. Experimental studies on assemblies of rods and computer simulation will be conducted to aid the development the theory. the results from the experimental studies and computer simulation along with the available date from studies on natural granular systems, such as sands, will be used to validate the developed theory.