Multi-Scale Experimental Investigation of Sliding Friction

滑动摩擦的多尺度实验研究

基本信息

批准号：
9908218
负责人：
Steven Glaser
金额：
$ 23.03万
依托单位：
University of California-Berkeley
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
1999
资助国家：
美国
起止时间：
1999-10-01 至 2002-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9908218&HistoricalAwards=false
关键词：
Multi Scale Experimental Investigation Sliding

Multi Scale Experimental Investigation Sliding

项目摘要

***9908218GlaserEngineers have always relied on rate- and state-dependent constitutive models(behavioral criteria). Recent advances by the condensed-matter physicscommunity have resulted in hypothetical theoretical mechanisms responsible forfrictional resistance to sliding. These models explain behaviors from angstromscale to kilometers-long earthquake dislocations, and provide a theoreticalframework for understanding material creep as well as self-healing slip on theSan Andreas fault. Since there has been little direct experimental proof thatthe posited fundamental physical mechanisms indeed are at work, the PIs willleverage their experimental and interpretive ability to image thesemicro-mechanisms. Given that the fundamental kinematics of frictional junctionsresults in production of phonons (vibrational, hence acoustic, energy), thecombination of quantitative acoustic emission and waveform inversion isuniquely able to image these kinematics. Glaser has developed surface andembeddable sensors proven capable by NIST of measuring picometer displacementsfrom 10 kHz to 1 MHz to within 3 dB. Studies show that the dynamic recordtransduced by these sensors match the theoretical kinematic waveformsremarkably well, allowing whole-waveform inversion for source kinematics ratherthan single-point moment tensor inversion. The results of this project will further science and engineering on severallevels. Fundamental understanding of the physical mechanisms behind slidingfriction, leading to improvement of basic understanding of the physical world. This will help refine current empirical understanding of friction and allowgreat improvement in mechanical design from nanomachines to sub-kilometer-scalestructures. In addition, fundamental questions about kilometer-scaleearthquake source mechanisms will be answered, in particular the issuessurrounding the notion of self-healing slip, thereby leading to an improvedunderstanding of the earthquake dislocation mechanism, and ultimately improvedseismic safety.***

*** 9908218GlaserEngineer一直依赖于速率和州依赖性的本构模型（行为标准）。凝结物理社区的最新进展导致了假设的理论机制，负责对滑动的影响。这些模型解释了从Angstromscale到长时间地震位错的行为，并为理解材料蠕变以及对Thesan Andreas断层的自我修复滑移提供了理论框架。由于几乎没有直接的实验证据表明，所提出的基本物理机制确实在起作用，因此PIS会将其实验性和解释能力图像形象形象。鉴于摩擦连接子在产生声子（振动，因此声学，能量）中的基本运动学，定量声发射的结合和波形反演的结合能够表现出这些运动学的形象。格拉瑟（Glaser）开发了表面和可安置的传感器，可通过测量10 kHz至1 MHz至3 dB以内的表皮表位移来证明。研究表明，这些传感器对这些传感器的动态记录转导的动态记录非常匹配理论运动波形，从而使源运动学的全波倒置替代了单点矩张量反演。该项目的结果将进一步在几项级别上进行科学和工程。对滑动陷阱背后的物理机制的基本理解，从而改善了对物理世界的基本理解。这将有助于完善当前对摩擦的经验理解，并有助于从纳米机器到亚公里量表的机械设计改善。此外，还将回答有关公里大规模的源机制的基本问题，尤其是发行自我修复滑移的概念，从而导致地震脱位机制的改善，并最终改善了震动的安全。*** *** ***