Abstract
A new type of annular shear tester was designed. The normal stress is measured with a load cell which is coaxially installed on the fixed upper cell. The shear stress is detected by the torque meter installed between a movable lower cell and a driving motor. The movable lower cell is supported with many ball bearings in order to minimize the friction force.
These devices enable us to conduct the continuous measurement of the yield locus of powders. Besides, the cohesive force is simultaniously measured.
The maximum normal stress applied reachhs 4Kg/cm2 which corresponds to the stresses of powder in real bunkers.
The shearing results measured by this apparatus were favourably compared with those measured by other current shear testers.
