Abstract
A direct shear tester with constant vertical loads has been developed which can measure simultaneously the shearing force and vertical displacement of powder bed under shearing with variable shearing cell diameter and shearing rate. The relations of the shearing stress and the vertical strain to the horizontal shearing strain (shearing process diagrams) have been determined under venous test conditions for 34 variety of powders, and it has been found that the patterns of the shearing process diagrams can be classified into one of 15 categories according to the characteristics of the powders and the test conditions.
