Exploring One-Dimensional Uniaxial Compression through a Granular Micromechanics Model

抄録

Uniaxial or one-dimensional compression is widely used in granular material processing to produce granular compacts and is a key experimental method for evaluating the compressibility of granular materials. In this study, the granular micromechanics approach (GMA) was applied to simulate the one-dimensional uniaxial compression behavior of granular packing. GMA offers a continuum modeling paradigm that connects the macroscale response to the grain-scale mechanisms. To describe the stiffening behavior that elasto-frictional granular materials exhibit in confined compression, the elastic energy functional and dissipation potential were modified from previous versions of GMA-based models. The elastic energy of a grain pair was formulated to include a higher-order dependence on the normal relative displacement of the grain pair. The dissipation potential was also modified by incorporating coupling between plastic parameters that characterize plastic deformation accumulation as the grain-pair experiences compression and/or tension during loading process. The modified model, derived in the framework of geometrically nonlinear deformations, was then applied to replicate experimentally measured 1D compression behavior of granular materials undergoing large compression. The results reveal nearly universal scaling with respect to the model parameters for predicting the behavior of granular materials composed of different particle types or initial density. A parametric study was conducted to determine the evolution of the microscale stored elastic energy and dissipation parameters in terms of grain-pair directions. In addition, this paper provides a brief literature review of experimental observations and modeling approaches related to powder compaction behavior.