Hurley Ryan C, Herbold Eric B, Pagan Darren C
Johns Hopkins University, Baltimore, MD 21218, USA.
Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
J Appl Crystallogr. 2018 Jun 28;51(Pt 4):1021-1034. doi: 10.1107/S1600576718006957. eCollection 2018 Aug 1.
Three-dimensional X-ray diffraction (3DXRD), a method for quantifying the position, orientation and elastic strain of large ensembles of single crystals, has recently emerged as an important tool for studying the mechanical response of granular materials during compaction. Applications have demonstrated the utility of 3DXRD and X-ray computed tomography (XRCT) for assessing strains, particle stresses and orientations, inter-particle contacts and forces, particle fracture mechanics, and porosity evolution . Although past studies employing 3DXRD and XRCT have elucidated the mechanics of spherical particle packings and angular particle packings with a small number of particles, there has been limited effort to date in studying angular particle packings with a large number of particles and in comparing the mechanics of these packings with those composed of a large number of spherical particles. Therefore, the focus of the present paper is on the mechanics of several hundred angular particles during compaction using 3DXRD to study the crystal structure, kinematics, stresses and rotations of angular quartz grains. Comparisons are also made between the compaction response of angular grains and that of spherical grains, and stress-induced twinning within individual grains is discussed.
三维X射线衍射（3DXRD）是一种用于量化单晶大集合体的位置、取向和弹性应变的方法，最近已成为研究压实过程中粒状材料力学响应的重要工具。应用表明，3DXRD和X射线计算机断层扫描（XRCT）在评估应变、颗粒应力和取向、颗粒间接触和力、颗粒断裂力学以及孔隙率演变方面具有实用性。尽管过去使用3DXRD和XRCT的研究已经阐明了少量颗粒的球形颗粒堆积和角形颗粒堆积的力学原理，但迄今为止，在研究大量角形颗粒堆积以及将这些堆积的力学原理与大量球形颗粒组成的堆积的力学原理进行比较方面所做的努力有限。因此，本文的重点是使用3DXRD研究几百个角形颗粒在压实过程中的力学原理，以研究角形石英颗粒的晶体结构、运动学、应力和旋转。还对角形颗粒和球形颗粒的压实响应进行了比较，并讨论了单个颗粒内的应力诱发孪生现象。
