Evaluation of the computer controlled dynamic yield locus tester (DYLT)

Shear cells based on the constant volume approach are a promising alternative to the constant load Jenike and rotational shear cell approaches. The purpose of this study was to further evaluate the computer controlled dynamic yield locus tester (DYLT) based on the constant volume approach. This was done by comparing the flow parameters of five test materials: 1) BCR limestone, 2) glass fibers, 3) ground silica, 4) microcrystalline cellulose, and 5) wheat flour, using the computer controlled Jenike tester (CCJT) and DYLT. Test results showed that the flow parameters, cohesion and angle of internal friction, measured using the CCJT and DYLT for BCR limestone, glass fibers and microcrystalline cellulose were statistically similar (p>0.05). Only one flow parameter value, cohesion at a consolidation stress of 10.7 kPa, for ground silica was significantly different (p<0.05) between the two experimental techniques. However, the magnitude of the F-statistic, 5.21, was similar to the F value at a level of significance of 0.05, 4.96. Three of six flow parameter values, i.e., cohesion and angle of internal friction, for wheat flour were significantly different (p<0.05) between the CCJT and DYLT. These differences are attributed to inconsistent post yield behavior. Minimal differences occurred between the experimental techniques, CCJT and DYLT, and the published data for BCR limestone.