Stress analysis of powder beds using constant-volume and constant-load shear tests: Characterization by repeated shearing and application to quasi-steady load shearing

Abstract

• Constant-volume and constant-load shear tests were conducted. • Normal and shear stresses acting on a shear plane were accurately measured. • Results obtained using the two test methods presented reasonable concurrence. • Constant-volume shear tester reproduced constant-load shear test results. • A quasi-steady load shear test method was proposed. Two types of high-performance shear test methods were employed to analyze the mechanical properties of powders. Both tests accurately measured the normal and shear stresses acting on the shear plane. Alumina powders with mass median diameters of 0.67, 4.0, 9.9, and 49 µm were used as samples. The effects of repeated shearing on the void fraction, stress relaxation ratio, stress transmission ratio, powder yield locus (PYL), consolidation yield locus (CYL), and critical state line (CSL) were determined using a constant-volume shear tester. The PYL and CSL were also measured using a constant-load shear tester, and the results obtained were compared. This comparison demonstrated a reasonable concurrence between the results obtained with the two testers. Furthermore, quasi-steady load shear tests were conducted using a constant-volume shear tester with feedback control, which demonstrated that the PYL could be obtained in a single shear test within a few minutes.