Numerical Modeling Describing the Effects of Heterogeneous Distributions of Asperities on the Quasi-static Evolution of Frictional Slip
Numerical Modeling Describing the Effects of Heterogeneous Distributions of Asperities on the Quasi-static Evolution of Frictional Slip
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DOI：
10.1007/s00603-017-1333-9
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发表时间：
2017-10
影响因子：
6.2
通讯作者：
P. Selvadurai;J. M. Parker;S. Glaser
中科院分区：
文献类型：
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作者：
P. Selvadurai;J. M. Parker;S. Glaser
更好地了解滑移如何沿着断层累积及其与剪切应力分解的关系有利于许多工程学科，例如水力压裂和理解诱发地震活动（等等）。沿着预先存在的断层形成的粗糙体抵抗界面两侧的相对运动，并且由于表面地形的相互作用而出现。在这里，我们采用有限元模型来模拟沿着名义上平坦的摩擦界面的圆形部分滑移粗糙体。我们的部分滑移粗糙体模型的剪切行为与 Cattaneo 描述的理论非常匹配。粗糙体模型用于模拟两个聚甲基丙烯酸甲酯之间形成的实验断层的一小部分，该断层由多个粗糙体组成，其位置和尺寸可以使用压敏薄膜直接测量。界面的准静态剪切行为针对循环载荷条件进行了建模，摩擦耗散（滞后）与法向应力相关。我们通过对空间中随机分布的粗糙体的对数正态尺寸分布进行综合建模来进一步加深我们的理解。合成分布保留了实验案例中的真实接触面积和尺寸分布的各个方面，使我们能够比较仅基于间距效应的本构行为。实验界面的牵引滑移行为似乎很大程度上受到粗糙体空间聚类的影响，而随机间隔的合成粗糙体分布中不存在这种聚类。整体界面剪切刚度的估计是根据本构牵引滑移行为确定的，并且与具有非相互作用粗糙体的多接触界面的理论估计相当。
A better understanding of how slip accumulates along faults and its relation to the breakdown of shear stress is beneficial to many engineering disciplines, such as, hydraulic fracture and understanding induced seismicity (among others). Asperities forming along a preexisting fault resist the relative motion of the two sides of the interface and occur due to the interaction of the surface topographies. Here, we employ a finite element model to simulate circular partial slip asperities along a nominally flat frictional interface. Shear behavior of our partial slip asperity model closely matched the theory described by Cattaneo. The asperity model was employed to simulate a small section of an experimental fault formed between two bodies of polymethyl methacrylate, which consisted of multiple asperities whose location and sizes were directly measured using a pressure sensitive film. The quasi-static shear behavior of the interface was modeled for cyclical loading conditions, and the frictional dissipation (hysteresis) was normal stress dependent. We further our understanding by synthetically modeling lognormal size distributions of asperities that were randomly distributed in space. Synthetic distributions conserved the real contact area and aspects of the size distributions from the experimental case, allowing us to compare the constitutive behaviors based solely on spacing effects. Traction-slip behavior of the experimental interface appears to be considerably affected by spatial clustering of asperities that was not present in the randomly spaced, synthetic asperity distributions. Estimates of bulk interfacial shear stiffness were determined from the constitutive traction-slip behavior and were comparable to the theoretical estimates of multi-contact interfaces with non-interacting asperities.