二维颗粒体系的力链网络结构及其宏观动力学响应研究

项目名称： 二维颗粒体系的力链网络结构及其宏观动力学响应研究

项目编号： No.11272048

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 张国华

作者单位： 北京科技大学

项目金额： 78万元

中文摘要： 颗粒物质是由大量离散固体颗粒组成的体系，广泛存在于自然界中。在颗粒物质中，外载荷有选择的沿着颗粒相互接触形成的路径（力链）传递，形成颗粒→力链网络→体系的多尺度结构。其中，力链网络是骨架，是确定颗粒物质力学性质的重要因素。目前，关于颗粒物质力链及其动力学演化方面的定量研究比较薄弱。本项目拟开展以下3方面研究：（1）利用光弹实验和离散元模拟获取二维颗粒系统力网络的信息，构建扰动前后应力改变量的空间关联函数，量化力链及力网络的结构特征，分析连续弹性介质模型的适用范围；（2）构建体系的动力学响应函数，定量分析体系对各种外部扰动的响应，研究不同加载条件下颗粒系统动力学响应的演化规律；（3）建立不同载荷下体系中软点与颗粒重排及应力变化量的关联，探索力链网络演化的结构起源。显然，本项目的研究将建立细观结构演化与宏观动力学的关联，拓展人们对颗粒物质动力学的理解，并在指导工程实践方面具有重要的应用价值。

中文关键词： 颗粒材料；离散元法；颗粒流；介观结构；动力学响应

英文摘要： The granular matter is a system composed of a large number of discrete macroscopic particles, which are widely existed in the world. In granular matter, the external loading transfers selectively along the path (force chain) which formed by the contacted particles. Then the structure, the particle → the network of force chain → the system, is formed. Where the network of force chain is the skeleton of the granular matter, and it is an important factor determining the mechanical characteristics of the granular matter. Up to now, the quantitative study on force chain and its dynamical evolution is scarce. The three aspects which will be studied in this project are as following: (1) The photoelastic experiment and the discrete element simulation will be used to obtain the information of the force networks of the two-dimensional granular system. The spatial correlation function of the stress change of particle after perturbation will be built to quantify the structural characteristics of the force chain and the force networks. And the applicable scope of the continuous elastic medium model will be analyzed. (2) The dynamical response function will be built to analyze quantificationally the response of the system to the external perturbations. The evolution of the dynamical response of the granular system under vario

英文关键词： granular material；discrete elements method；granular fluid；mesoscopic structure；dynamical response