Localizing signatures of catastrophic failure (LOCAT)

复杂的材料，如陶瓷、岩石和地壳，在长期持续或波动的压力下，往往会以灾难性的方式破裂。类似的灾难性失败事件也发生在生物和社会系统中，如大规模灭绝、临界点和股市崩盘，并已开发出一系列工具，以在“复杂性科学”的一般框架下解决这些问题。在这里，我们将使用这些工具来寻找行为模式及其潜在原因，从对复合天然或合成材料施加压力的相对稳定阶段过渡到最终失效。我们将专注于无序的多孔介质，如天然岩石，并结合使用高分辨率C-T扫描的表征与变形和破坏过程的数值模拟，以及对实验室和自然数据的分析，以达到地球物理尺度的变形，以解决以下问题。i.变形的局部化在全球加速到破坏中起什么作用？ii.加速阶段的统计可预测性是什么？iii.损伤的时空演变是否有任何通用的特征，从而可以估计单个样品的寿命？IV.将模拟和实验室测试与地球物理尺度联系起来的尺度关系是什么。

Complex materials, like ceramics, rocks and the Earth's crust, often break in a catastrophic manner, after a long period of sustained or fluctuating stress. Similar catastrophic failure events also happen in biological and social systems, as mass extinctions, tipping points, and stock market crashes, and a range of tools have been developed to address these under the general framework of 'complexity science'. Here we will use these tools to look for patterns of behaviour, and their underlying causes, in the transition from the relatively stable phase of stressing a composite natural or synthetic material to its ultimate failure. We will focus on disordered porous media such as natural rocks and combine characterization using high-resolution C-T scanning with numerical modelling of the deformation and failure process, and analysis of laboratory and natural data on deformation up to the geophysical scale, in order to address the following questions.I. What role does localisation of deformation play in global acceleration to failure?II. What is the predictability of the acceleration phase in statistical terms?III. Are there any universal signatures of the spatio-temporal evolution of damage which permit lifetime estimates for single samples?IV. What are the scaling relations that link simulations and laboratory tests to the geophysical scale.