Recent Milestones in Unraveling the Full-Field Structure of Dynamic Shear Cracks and Fault Ruptures in Real-Time: From Photoelasticity to Ultrahigh-Speed Digital Image Correlation
Recent Milestones in Unraveling the Full-Field Structure of Dynamic Shear Cracks and Fault Ruptures in Real-Time: From Photoelasticity to Ultrahigh-Speed Digital Image Correlation
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DOI：
10.1115/1.4045715
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发表时间：
2020-03
期刊：
影响因子：
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通讯作者：
A. Rosakis;V. Rubino;N. Lapusta
中科院分区：
文献类型：
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作者：
A. Rosakis;V. Rubino;N. Lapusta
过去几十年来，动态断裂力学取得了巨大的成就。然而，直到最近才能够通过实验量化动态裂缝的全场行为。在这里，我们回顾了我们最近关于动态剪切破裂时间演化的全场量化的工作。我们新开发的基于数字图像相关性与超高速摄影的方法彻底改变了测量高度瞬态现象的能力，并能够解决破裂动力学的关键问题。最近的里程碑包括可视化生长破裂附近的完整位移、粒子速度、应变、应力和应变率场，捕获单个破裂生长期间动态摩擦的演变，以及破裂速度限制的详细研究。例如，动摩擦一直是控制摩擦破裂如何发展的最大未知数，但到目前为止，还不可能测量自发破裂传播过程中的动摩擦并了解其对其他量的依赖性。我们最近的测量通过同时跟踪破裂界面上的牵引力和滑动速度，可以解开其对滑移、滑移速度及其历史的复杂依赖关系。在另一个应用中，我们发现了以前的方法无法检测到的新现象，例如与粘弹性材料中剪切破裂的“超音速”传播相关的压力冲击前沿的形成，其中波速强烈依赖于应变率。
The last few decades have seen great achievements in dynamic fracture mechanics. Yet, it was not possible to experimentally quantify the full-field behavior of dynamic fractures, until very recently. Here, we review our recent work on the full-field quantification of the temporal evolution of dynamic shear ruptures. Our newly developed approach based on digital image correlation combined with ultrahigh-speed photography has revolutionized the capabilities of measuring highly transient phenomena and enabled addressing key ques- tions of rupture dynamics. Recent milestones include the visualization of the complete displacement, particle velocity, strain, stress and strain rate fields near growing ruptures, capturing the evolution of dynamic friction during individual rupture growth, and the detailed study of rupture speed limits. For example, dynamic friction has been the big- gest unknown controlling how frictional ruptures develop but it has been impossible, until now, to measure dynamic friction during spontaneous rupture propagation and to understand its dependence on other quantities. Our recent measurements allow, by simul- taneously tracking tractions and sliding speeds on the rupturing interface, to disentangle its complex dependence on the slip, slip velocity, and on their history. In another application, we have uncovered new phenomena that could not be detected with previous methods, such as the formation of pressure shock fronts associated with “supersonic” propagation of shear ruptures in viscoelastic materials where the wave speeds are shown to depend strongly on the strain rate.