2025-03-13 カリフォルニア工科大学 (Caltech)
＜関連情報＞
- https://www.caltech.edu/about/news/everything-flows-refining-the-laws-of-friction-in-caltechs-seismological-wind-tunnel
- https://www.nature.com/articles/s41586-025-08673-0
静止しているように見える摩擦界面の滑走と修復 Sliding and healing of frictional interfaces that appear stationary
Krittanon Sirorattanakul,Stacy Larochelle,Vito Rubino,Nadia Lapusta & Ares J. Rosakis
Nature Published:12 March 2025
DOI:https://doi.org/10.1038/s41586-025-08673-0
Abstract
Frictional interfaces are found in systems ranging from biological joints to earthquake faults. When and how these interfaces slide is a fundamental problem in geosciences and engineering. It is believed that there exists a threshold shear force, called static friction, below which the interface is stationary, despite many studies suggesting that this concept is outdated. By contrast, rate-and-state friction formulations predict that interfaces are always sliding, but this feature is often considered an artefact that calls for modifications. Here we show that nominally stationary interfaces subjected to constant shear and normal loads, with a driving force that is notably below the classically defined static friction for which creep is known to occur, are sliding, but with diminishingly small rates down to 10−12 m s−1. Our precise measurements directly at the interface are enabled by digital image correlation. This behaviour contradicts classical models of friction but confirms the prediction of rate-and-state friction. The diminishing slip rates of nominally stationary interfaces reflect interface healing, which would manifest itself in higher peak friction in subsequent slip events, such as earthquakes and landslides, substantially modifying their nucleation and propagation and hence their hazard.
