【作者】 王伟明；

【导师】 胡林；

【作者基本信息】 贵州大学 ， 理论物理， 2007， 硕士

【摘要】 本文用实验的方法研究了颗粒物质中存在空洞时对体系力链结构的影响。当在颗粒物质中竖直提拉圆棒时其下端将产生空洞，空洞的存在导致颗粒体系内部力链结构发生变化，变化的情况可通过测定棒受到的摩擦力来反映。在前人研究的基础上，我们结合自己的实验目的改进了实验装置，分别测量了不同颗粒填充高度(即空洞产生的深度)，颗粒直径，筒仓直径和探测棒直径条件时空洞对颗粒物质中应力变化的影响。实验结果表明，空洞对颗粒物质中应力变化的影响只与空洞产生的深度存在着一定的关系，而与颗粒直径，筒仓直径和探测棒直径无关。利用origin软件对实验数据拟合得到由于空洞的存在导致颗粒体系力链结构崩塌的时间t与空洞产生的深度h存在着如下关系：t=Aexp(h／λ)+B，公式中各拟合参数分别为：A=7.5+0.3，B=2.4±0.4，λ=70.0±0.7。因为t只与空洞产生深度h有关，因此，具有普适的意义，可以应用到与颗粒物质相关的体系中。我们还设计了二维的空洞实验，以便更好的理解和观察颗粒体系内部在空洞影响时颗粒力链的变化情况。更多还原

【Abstract】 The change of force chain influenced by cavity effect in granular matter is studied experimentally. When pull out a rod from granular matter, that should exist a cavity under it and the force chain structure will be changed, the change should be studied by the friction of the rod. Based on former research, we improved our experimental set, measured the cavity effect of different depth of the filling granules(viz. the depth of the cavity), different diameter of the granules, different diameter of the container and different diameter of the rod. We found that the granular matter is influenced by the cavity’s depth only, and this relationship is independent of the diameter of the granules, diameter of the container and diameter of the rod. By using origin soft, We found the relationship between the breakdown time t and thecavity’s depth h is t= Aexp(h/λ.) +B and A=7.57±0.3 , B=2.45±0.4 ,λ=70.00±0.7. This expression could be used in the other granular system. We do an two-dimension experiment at the same time, to understand the inside situation of the granular matter clearly.更多还原