Friction, Fatigue and Failure: a Multiscale Approach Linking Physics, Fabrication and Geophysical Phenomena

摩擦、疲劳和失效：连接物理、制造和地球物理现象的多尺度方法

• 批准号: 0606092
• 负责人: Jean Carlson
• 金额: $ 27万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0606092&HistoricalAwards=false
• 关键词: Friction; Fatigue; Failure; Multiscale; Approach

TECHNICAL SUMMARY:This award supports interdisciplinary theoretical research and education to advance the basic understanding of the physics which underlies materials which are intrinsically heterogeneous, internally structured, under stress, and far from equilibrium. Focus areas of the research include basic theory and multiresolution studies of the interplay between dynamics and heterogeneity in friction, fatigue, and failure of amorphous solids and granular materials, with applications in geophysics and friction compensation and control.The project begins at the smallest scales, with plans for continuing numerical simulations of sheared granular materials. Building on the PI's recent work using contact dynamics to probe the range of validity of constitutive laws derived in the dilute (kinetic theory) and dense (shear transformation zones) limits, plans include investigation of flows in hoppers and other geometries, as well as detailed studies of the emergence of force correlations and jamming in the dense regime. Results will be compared to laboratory friction studies, as well as rate and state constitutive laws. The simulations will also be expanded to investigate effects of more complex particle shapes and broader size distributions, aging and wear of particles, detailed local friction models, as well as hydrodynamic dissipation associated with fluids.At intermediate scales, investigations focus on derivation and verification of constitutive laws describing granular systems, amorphous solids, gels, and lubricated interfaces. A unified, multiscale approach to constitutive laws as an intermediate between microscopic dynamics, and the ultimate implications for larger scales (stick-slip instabilities, transient overshoots, shear band formation, and controllability) is described.The approach expands basic theory for nonequilibrium statistical physics using methods from computer science and engineering systems theory. The project also focuses on quantitative connections with recent laboratory experiments, which directly probe the microscopic spatio-temporal dynamics of contacts, aging, flash heating, and fluids.At macroscopic scales, the proposal describes continuing geophysical applications as well as new work on technological applications in friction compensation and control.Work on geophysical applications includes interactions between dynamic crack fronts and material inhomogeneities, as well as rupture dynamics in the presence of spatial material gradients (which may be due to temperature or pressure variations, aging, or wear). Work on control of friction represents a new area for the PI, and leverages her group's combined expertise in physical friction models and control theory to develop and test controllers for device fabrication.Intellectual Merit: The research on deformation, dissipation, aging, wear, and fracture in dense, amorphous materials, involves development and implementation of new theory and simulation tools spanning a broad range of scales. This both expands basic understanding of physical systems far from equilibrium, and provides new methodologies for describing of other complex, interconnected systems which exhibit aging and cascading breakdown phenomena.Broader Impact: Understanding friction, fatigue, and failure is currently a primary limiting factor both in developing new technologies and forecasting natural hazards. The work proposed here will lead to controllers for device applications, and models for seismic hazard estimation. Related hands on demonstrations will be developed for public and K-12 education and outreach activities, aimed at public awareness and safety, and increasing representation of women and minorities in the physical sciences.NON-TECHNICAL SUMMARY:This award supports interdisciplinary theoretical research and education to advance the fundamental understanding of friction, fatigue, and fracture in solids and granular materials. A fundamental understanding with predictive power of these phenomena remains elusive and challenging, and would find widespread applications from materials failure in many settings to geophysical hazards. At a deeper level, friction, fatigue, and fracture serve broadly as prototypical examples for some classes of complex systems for which fundamental principles governing their behavior are sought. Such universal principles would be applicable to many complex systems, not just the one in which they were discovered. Their discovery would advance the area of statistical physics that focuses on systems that are far from equilibrium. The PI's approach will span the many length scales characteristic of these phenomena. It is inherently multidisciplinary; it brings to bear elements of computational science, engineering, geophysics, physics, and materials science on well characterized systems to advance understanding at a fundamental level. Understanding friction, fatigue, and failure is currently a primary limiting factor both in developing new technologies and forecasting natural hazards. The work proposed here will lead to controllers for device applications, and models for seismic hazard estimation. Related hands on demonstrations will be developed for public and K-12 education and outreach activities, aimed at public awareness and safety, and increasing representation of women and minorities in the physical sciences.

技术摘要：该奖项支持跨学科的理论研究和教育，以促进对物理学基础的基本理解，这些物理学是本质上异质，内部结构，在压力下且远离平衡的材料。该研究的重点领域包括基础理论和多解析研究，该研究在摩擦，疲劳和非晶状固体和颗粒状材料的失败中的相互作用和异质性之间的相互作用，以及在地球物理学和摩擦补偿和控制中的应用。该项目始于最小的尺度，并计划连续进行剪切的粒状粒状材料的数值模拟。基于PI的最新工作，使用接触动力学来探测稀释（动力学理论）和致密（剪切转换区）限制中构成定律的有效性范围，包括对料斗和其他几何形状中的流量进行的研究，以及对力量相关性和密集制度的出现的详细研究。结果将与实验室摩擦研究以及速率和州构成法律进行比较。该模拟还将扩展以研究更复杂的粒子形状和更广泛的尺寸分布，颗粒的衰老和磨损，详细的局部摩擦模型以及与流体相关的流体动力耗散。描述了一种统一的多尺度方法作为微观动力学之间的中间人，以及对较大量表的最终影响（粘粘剂不稳定性，瞬态过冲，剪切带形成和可控性）。该方法扩展了使用计算机科学和工程学系统理论的非平衡统计物理学的基础理论。该项目还侧重于与最近的实验室实验的定量连接，直接探测了接触，衰老，衰老，闪光加热和流体的微观时空时空动态。在宏观尺度上，该提案描述了在摩擦补偿和控制中的新工作应用程序的地球物理应用以及在摩擦互动中的应用。以及在存在空间材料梯度的情况下（可能是由于温度或压力变化，衰老或磨损）的破裂动力学。控制摩擦的工作代表了PI的新领域，并利用她的团队在物理摩擦模型和控制理论中的综合专业知识来开发和测试设备制造的控制器。IntlectualFure：关于变形，耗散，衰老，衰老，磨损和破裂在密集的，无律，无律的开发和实施新理论和模拟范围的范围的研究。这既扩大了对物理系统远非平衡的基本了解，并且为描述其他复杂的，相互联系的系统提供了新的方法，这些系统表现出衰老和级联分解现象。Boader的影响：了解摩擦，疲劳和故障目前是开发新技术和预测自然危害的主要限制因素。这里提出的工作将导致用于设备应用的控制器，以及用于地震危险估计的模型。相关的示威动手将针对公共和K-12教育和外展活动开发，旨在公众意识和安全，并增加对物理科学中妇女和少数群体的代表性。Non-Technical摘要：该奖项支持跨学科的理论研究和教育，以促进对摩擦，疲劳，疲劳和固体材料的基本了解。具有这些现象的预测能力的基本理解仍然难以捉摸且具有挑战性，并且会发现从许多情况下材料失败到地球物理危害的广泛应用。 在更深层次的层面上，摩擦，疲劳和断裂广泛用作某些复杂系统的原型示例，这些系统的基本原理是寻求其行为的基本原理。这种通用原则将适用于许多复杂系统，而不仅仅是它们被发现的系统。他们的发现将推进统计物理的领域，该物理学的重点是远非平衡的系统。 PI的方法将跨越这些现象的许多长度尺度。它本质上是多学科的；它带来了计算科学，工程，地球物理学，物理学和材料科学的要素，这些元素是具有良好特征的系统，以提高基本层面的理解。当前，了解摩擦，疲劳和故障是开发新技术和预测自然危害的主要限制因素。这里提出的工作将导致用于设备应用的控制器，以及用于地震危险估计的模型。相关的示威动手将针对公共和K-12教育和外展活动开发，旨在公众意识和安全，并不断提高妇女和少数民族在物理科学中的代表。