Hurley R C, Lind J, Pagan D C, Homel M A, Akin M C, Herbold E B
Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
Phys Rev E. 2017 Jul;96(1-1):012905. doi: 10.1103/PhysRevE.96.012905. Epub 2017 Jul 24.
We performed experiments combining three-dimensional x-ray diffraction and x-ray computed tomography to explore the relationship between microstructure and local force and strain during quasistatic granular compaction. We found that initial void space around a grain and contact coordination number before compaction can be used to predict regions vulnerable to above-average local force and strain at later stages of compaction. We also found correlations between void space around a grain and coordination number, and between grain stress and maximum interparticle force, at all stages of compaction. Finally, we observed grains that fracture to have an above-average initial local void space and a below-average initial coordination number. Our findings provide (1) a detailed description of microstructure evolution during quasistatic granular compaction, (2) an approach for identifying regions vulnerable to large values of strain and interparticle force, and (3) methods for identifying regions of a material with large interparticle forces and coordination numbers from measurements of grain stress and local porosity.
我们进行了结合三维X射线衍射和X射线计算机断层扫描的实验，以探索准静态颗粒压实过程中微观结构与局部力和应变之间的关系。我们发现，颗粒周围的初始空隙空间和压实前的接触配位数可用于预测压实后期易出现高于平均水平的局部力和应变的区域。我们还发现，在压实的各个阶段，颗粒周围的空隙空间与配位数之间以及颗粒应力与最大颗粒间力之间存在相关性。最后，我们观察到发生断裂的颗粒具有高于平均水平的初始局部空隙空间和低于平均水平的初始配位数。我们的研究结果提供了：（1）准静态颗粒压实过程中微观结构演变的详细描述；（2）一种识别易出现大应变值和颗粒间力区域的方法；（3）从颗粒应力和局部孔隙率测量中识别具有大颗粒间力和配位数的材料区域的方法。
