STATIC FRICTION FORCE ON PROBING ROD IN GRANULARPILE IN SMALL CONTAINER
小筒仓内颗粒中探测棒受到的最大静摩擦力

Experiments were conducted to investigate the maximum static friction force on a dragged probing rod in the uniform granular pile contained in a cylindrical vessel. It is observed that the force obtained is greater than that of Jassen Model, when the gap between the wall and the rod is smaller than 50 times of the spheres diameter. When the diameter of vessel is small, the force is related to the shape of the detecting rod. This strange behavior is due to the fact that the scattered granular can not be approximated as a continuum medium when the diameter (D) is small. The force chain in the granular pile plays a major role.