Theoretical Analysis of Joint Friction

关节摩擦力的理论分析

• 批准号: 0336840
• 负责人: Joseph Walsh
• 金额: $ 9万
• 依托单位: Walsh Joseph B
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-15 至 2005-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0336840&HistoricalAwards=false
• 关键词: Theoretical; Analysis; Joint; Friction

Friction experiments, where the applied shear force required to produce slip between normally planar rock surfaces, are designed to simulate displacement observed on natural faults. One difficulty that arises in the interpretation of experimental results is the problem of scale: the size of the samples is measured in centimeters, whereas natural faults are many kilometers in length and depth; and the disparity in the scales of time that are characteristic of natural and laboratory processes is as great. Walsh is studying ways to bridge the gap caused by the disparity in time and length scales by developing theoretical models which simulate behavior observed experimentally. He is now studying slip between rough elastic surfaces where slip, opposed by Coulomb friction, occurs on the microscale at the contacts between asperities. This analysis, which has immediate application to sliding experiments in the laboratory, is the basis for the analysis of earthquake faulting, where 'roughness' of lab samples is equivalent to heterogeneity in the normal stress and shear stress fields at the fault interface. The study can be modified by introducing more complicated frictional behavior, such as the rate-state model, now being studied in several laboratories.

摩擦实验，其中所施加的剪切力需要产生正常平面岩石表面之间的滑动，旨在模拟天然断层上观察到的位移。 在解释实验结果时出现的一个困难是尺度问题：样品的大小是以厘米为单位测量的，而自然断层的长度和深度是许多公里;自然过程和实验室过程所特有的时间尺度的差异也是巨大的。 沃尔什正在研究如何通过开发模拟实验观察到的行为的理论模型来弥合由时间和长度尺度的差异造成的差距。 他现在正在研究滑动粗糙的弹性表面之间的滑动，反对库仑摩擦，发生在微尺度上的接触粗糙。 这种分析，它有直接的应用程序在实验室中的滑动实验，是地震断层分析的基础上，其中的“粗糙度”的实验室样品相当于在断层界面的正应力和剪应力场的不均匀性。 这项研究可以通过引入更复杂的摩擦行为来修改，例如目前正在几个实验室研究的速率状态模型。