Materials World Network: Crackling Noise

材料世界网：噼啪声

• 批准号: 1312160
• 负责人: James Sethna
• 金额: $ 40万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-15 至 2017-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1312160&HistoricalAwards=false
• 关键词: Materials; World; Network; Crackling; Noise

TECHNICAL SUMMARY:Crackling noise is the intermittent, scale-invariant response of materials systems to external forces. The Earth's crust crackles through earthquakes when sheared by continental drift; paper crackles when crumpled; iron crackles (Barkhausen noise) when magnetized; nanowires crackle when bent; bones crackle before they fracture. The broad range of event sizes in each of these systems reflects emergent scale invariance, which we understand using scaling methods underpinned by renormalization-group theory. The field of crackling noise is maturing scientifically, where identification and quantification of universal scaling functions and corrections to scaling are playing a central role in future applications. With support from the Division of Materials Research, the investigators in the US/Italian Materials World Network project will develop and hone methods to find effective, powerful multivariable scaling functions to describe the effects of long-range fields on crackling noise in magnets and glassy metals, to understand crossovers between different types of emergent scale invariance, and to test basic assumptions in the field about the relation of continuous evolution models and lattice models. In each project, they propose to systematically analyze analytic, singular, and subdominant corrections to the theory, rigorously assess statistical and systematic errors, and extend the realm of applicability of these powerful theories.NON-TECHNICAL SUMMARY:Many systems, when squeezed, stretched, or twisted, emit crackling noise. The earth's crust crackles through earthquakes as the continents drift apart; bones crackle before they break, paper crackles when crumpled. While a nuisance in many practical applications, this noise can also be useful in testing and predicting failure in materials. The noise also becomes more severe the smaller the system, and can be dominant for some nanoscale systems (forming wires on integrated circuits in modern electronics, for example). Crackling noise happens when a slow force produces a series of sharp events with an enormous range of sizes. In the past two decades, the investigators have explained why crackling noise arises, using tools from statistical mechanics. In this joint international project, they will lead a team of graduate students and post-docs from the US and Italy to turn this explanation into a quantitative tool for predicting and controlling crackling noise. This interdisciplinary project will expose theoretical physics students both to state-of-the art tools in statistical mechanics and to practical materials problems in engineering fracture, nanotechnology and microelectronics.

技术总结：爆裂噪声是材料系统对外力的间歇性、标度不变的响应。地壳在大陆漂移的剪切作用下会在地震中发出噼啪声;纸张在被弄皱时会发出噼啪声;铁在磁化时会发出噼啪声（巴克豪森噪声）;纳米线在弯曲时会发出噼啪声;骨头在断裂前会发出噼啪声。在这些系统中，事件大小的广泛范围反映了涌现的尺度不变性，我们使用以重整化群理论为基础的尺度方法来理解这一点。爆裂噪音领域在科学上正在成熟，通用缩放函数的识别和量化以及缩放校正在未来的应用中发挥着核心作用。在材料研究部门的支持下，美国/意大利材料世界网络项目的研究人员将开发和磨练方法，以找到有效的，强大的多变量标度函数来描述长距离场对磁铁和玻璃金属中爆裂噪声的影响，了解不同类型的紧急标度不变性之间的交叉，并检验了连续演化模型与格点模型之间关系的基本假设。在每一个项目中，他们提出系统地分析理论的解析、奇异和次显性修正，严格评估统计和系统误差，并扩展这些强大理论的适用范围。非技术性总结：许多系统，当被挤压、拉伸或扭曲时，会发出噼啪声。当大陆漂移时，地壳在地震中噼啪作响;骨头在断裂前噼啪作响，纸张在揉皱时噼啪作响。虽然在许多实际应用中是一种讨厌的东西，但这种噪音在测试和预测材料失效方面也很有用。系统越小，噪声也变得越严重，并且对于某些纳米级系统（例如，在现代电子设备中的集成电路上形成导线）可能是主导性的。当一个缓慢的力产生一系列大小不等的尖锐事件时，就会产生噼啪声。在过去的二十年里，研究人员已经解释了为什么会产生噼啪声，使用统计力学的工具。在这个国际合作项目中，他们将带领一个由来自美国和意大利的研究生和博士后组成的团队，将这种解释转化为预测和控制爆裂噪声的定量工具。这个跨学科的项目将使理论物理学生接触统计力学中最先进的工具，以及工程断裂，纳米技术和微电子学中的实际材料问题。