颗粒流切应力波动与力链结构  

Shear stress fluctuation and force chain structure in the granular flow

作　　者：夏建新[1,2] 吉祖稳 毛旭锋[1] 曹华德[1] 

机构地区：[1]中央民族大学生命与环境科学学院,北京100081 [2]流域水循环模拟与调控国家重点实验室,北京100038

出　　处：《科学通报》2013年第13期1200-1203,共4页Chinese Science Bulletin

基　　金：中央民族大学"985工程"项目(MUC98507-08);国家自然科学基金(50879096;51179213)资助

摘　　要：颗粒流动过程中形成的力链结构与剪切速度特征关系密切.利用同心圆筒实验研究了颗粒中慢速流动过程中切应力波动规律和力链形成条件.研究结果表明,不同剪切速度下和颗粒直径条件下颗粒切应力波动幅度有较大差异,但切应力波动频谱曲线均呈现反"S"形状,正应力高值压痕实验可以揭示颗粒流中形成的动态力链结构,不同条件下形成力链的临界条件不同.本文研究结果对分析自然界和工业领域颗粒流问题具有借鉴意义.The force chain structure formed in granular flow has a great effect on shear stress of the granular.In this paper,we studied on the fluctuation of shear stress and formation of the force chain structures in the granular with slow flow using concentric cylinder method.The experimental results show that the frequency and amplitude of the shear stress fluctuation change obviously at different shearing velocity and granular size,and the frequency distribution of the stress fluctuation has an inverse ＂S＂ shape.At the same time,the carbon paper depression approach was used to record the quantity and distribution of the stress points,which act on the cylinder wall due to the high pressure caused by the force chain structure.The results also verify that the shear velocity and the particle size influence the formation of the force chain at the critical formation conditions,leading to different distribution of the high pressure points.

关 键 词：颗粒流 切应力波动 力链结构 

分 类 号：TQ021[化学工程]