Continuum description for the characteristic resistance sensed by a cylinder colliding against granular medium  

作　　者：PANG Yong LIU CaiShan 

机构地区：[1]State Key Laboratory for Turbulence and Complex Systems,College of Engineering,Peking University

出　　处：《Science China(Physics,Mechanics & Astronomy)》2013年第8期1428-1436,共9页中国科学：物理学、力学、天文学（英文版）

基　　金：the National Natural Science Foundation ofChina (Grant No. 11132001)

摘　　要：In this paper, we experimentally and theoretically study the resistance force that develops when a cylinder with a flat face colliding against dry quartzite sand. Observations from experimental data clearly show that the acceleration curves are characterized by a double-peak structure. The first agitated peak can be attributed to a shock process where sand responds elastically, and the valley bottom in the double-peak structure is related to a limited plastic load when a fully plastic region is formed in the sand, while the second agitated peak corresponds to a the occurrence of the maximum of viscous force in a homogeneous developed bulk flow. We use slip line theory (SL) developed in plastic mechanics to capture the value at the valley bottom, adopt the double shearing theory (DS), together with a Local Rheological Constitutive Law (LRCL) suggested in this paper, to capture the drag force generated in a homogeneous bulk flow. Good agreements in the comparisons between numerical and experimental results support the characteristic resistance by the cylinder to predict granular states.In this paper, we experimentally and theoretically study the resistance force that develops when a cylinder with a flat face colliding against dry quartzite sand. Observations from experimental data clearly show that the acceleration curves are characterized by a double-peak structure. The first agitated peak can be attributed to a shock process where sand responds elastically, and the valley bottom in the double-peak structure is related to a limited plastic load when a fully plastic region is formed in the sand, while the second agitated peak corresponds to a the occurrence of the maximum of viscous force in a homogeneous developed bulk flow. We use slip line theory （SL） developed in plastic mechanics to capture the value at the valley bottom, adopt the double shearing theory （DS）, together with a Local Rheological Constitutive Law （LRCL） suggested in this paper, to capture the drag force generated in a homogeneous bulk flow. Good agreements in the comparisons between numerical and experimental results support the characteristic resistance by the cylinder to predict granular states.

关 键 词：granular material penetrating dynamics rheological property 

分 类 号：O35[理学—流体力学]