An apparatus for confined triaxial testing of single particles

Abstract

A novel triaxial apparatus employing overlapping rigid boundaries has been designed and constructed for experimental measurement of contact forces under confined compression of single granules in the mm-scale. The performance of the apparatus was evaluated by performing uniaxial and triaxial compression experiments on ideal elastic-plastic materials.Compression curves were compared with the fully plastic Abbott-Firestone contact model and with results from FEM simulations. The increase in contact force associated with confined conditions was observed in the compression curves from triaxial compression experiments, as supported by predictions from simulations using single particle contact models. Hence, a new method for the assessment of mechanical behaviour of single particles under confined compression can be considered as established.

Stepwise Homogeneous Melting of Benzene Phase I at High Pressure

“…The phase III may appear on the melting pathway at lower temperatures. These comparisons indicate that the metastable structure that we found in this study is likely to appear under the isotropic pressure control, which can be realized by the recently developed experimental techniques [59][60][61].…”

Investigations of single microcrystalline cellulose-based granules subjected to confined triaxial compression

“…For the triaxial compression experiments, an apparatus for confined triaxial compression of single particles was used. This apparatus was earlier constructed and evaluated for nominally ideal elasticplastic particles [36]. The apparatus employs a mechanism first introduced by Hambly [37] for triaxial testing of soil specimens, and is to our knowledge the first to employ this mechanism to study single particles in the mm-scale.…”

“…Through this configuration, the punches are allowed to move independently, sliding with negligible friction past each other and narrowing the rectangular box contained between them (see Figure 1b). A detailed description of the apparatus can be found in the work by Jonsson et al [36].…”

Contact radius and curvature corrections to the nonlocal contact formulation accounting for multi-particle interactions in elastic confined granular systems

“…Of particular interest is the mechanical response of single particles under confined conditions, most commonly studied using uniaxial compression experiments (Liu, Williams & Briscoe, 1998;Lu, Tung, Hung, Shiau & Hwang, 2001;Shima, Tatara, Iio, Shu & Lucero, 1993;Tatara, Shima & Lucero, 1991;Topuz & Okay, 2009;Zhang, Kristiansen & Liu, 2007). Recently, an apparatus has been developed for triaxial testing of single particles (Jonsson, Gråsjö, Nordström, Johansson & Frenning, 2015), providing a more realistic insight into the behavior of individual particles during powder compaction.…”