2014/10/08 by Olukayode I. Imole, Imole, Olukayode I., Maria Paulick +13
Physics and Astronomy · #FOS: Physical sciences #Soft Condensed Matter (cond-mat.soft) #Statistical Mechanics (cond-mat.stat-mech) #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.48550/arxiv.1410.2151
arxiv created 2014/10/08 · arxiv updated 2014/10/09
We present findings from uniaxial (oedometric) compression tests on two cohesive industrially relevant granular materials (cocoa and limestone powder). Experimental results are presented for the compressibility, tested with two devices -- the FT4 Powder Rheometer and the custom made lambdameter. We focus on the stress response and the slow relaxation behavior of the cohesive samples tested. After compression ends, at constant volume, the ongoing stress relaxation is found to follow a power law consistently for both cohesive powders and for the different testing equipments. A simple (incremental algebraic evolution) model is proposed for the stress relaxation in cohesive powders, which includes a response timescale along with a second, dimensionless relaxation parameter. The reported observations are useful for both the improvement of discrete element simulations and constitutive macroscopic models for cohesive granular materials.