Investigating shock processes in bimodal powder compaction through modelling and experiment at the mesoscale
Investigating shock processes in bimodal powder compaction through modelling and experiment at the mesoscale
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DOI：
10.1016/j.ijsolstr.2018.12.025
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发表时间：
2019-05
影响因子：
3.6
通讯作者：
J. Derrick;M. Rutherford;D. Chapman;T. Davison;J. P. Duarte;L. Farbaniec;P. Bland;D. Eakins;G. Collins
中科院分区：
文献类型：
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作者：
J. Derrick;M. Rutherford;D. Chapman;T. Davison;J. P. Duarte;L. Farbaniec;P. Bland;D. Eakins;G. Collins
冲击驱动压实是一种提出的机制，从许多陨石衍生的原始双峰粒状混合物的石化。我们提出了一个数值实验的中尺度研究，调查在冲击压实这种异质性的物质，使用模拟材料的基本过程。实验在欧洲同步辐射设施进行，产生实时，原位，X射线照片的冲击波的通道在代表性的颗粒系统。使用冲击物理代码和几何上与实验相同的设置进行中尺度模拟。我们考虑了两种情况：纯矩阵，矩阵与一个单一的球粒。在纯粉末设置中，在冲击位置和冲击后压实方面，实验和模型之间发现了良好的一致性。当考虑一个单一的颗粒嵌入在基质中，我们观察到在其附近的空间孔隙度各向异性，压实是在该地区直接冲击的粮食，并在其李少。我们引入了孔隙度矢量C，它指向球粒上最低压实度的方向。这种依赖于方向的观测可能会提供一种新的方法来解码陨石过去经历的单一冲击波的大小和方向
Impact-driven compaction is a proposed mechanism for the lithification of primordial bimodal granular mixtures from which many meteorites derive. We present a numerical-experimental mesoscale study that investigates the fundamental processes in shock compaction of this heterogeneous matter, using analog materials. Experiments were performed at the European Synchrotron Radiation Facility generating real-time,in-situ, X-ray radiographs of the shock’s passage in representative granular systems. Mesoscale simulations were performed using a shock physics code and set-ups that were geometrically identical to the experiments. We considered two scenarios: pure matrix, and matrix with a single chondrule. Good agreement was found between experiments and models in terms of shock position and post-shock compaction in the pure powder setup. When considering a single grain embedded in matrix we observed a spatial porosity anisotropy in its vicinity; the compaction was greater in the region immediately shockward of the grain, and less in its lee. We introduced the porosity vector,C, which points in the direction of lowest compaction across a chondrule. This direction-dependent observation may present a new way to decode the magnitude, and direction, of a single shock wave experienced by a meteorite in the past