Nucleation of frictional sliding by coalescence of microslip

Schär, Styfen; Albertini, Gabriele; Kammer, David S.

Abstract

The onset of frictional motion is mediated by the dynamic propagation of a rupture front, analogous to a shear crack. The rupture front nucleates quasi-statically in a localized region of the frictional interface and slowly increases in size. When it reaches a critical nucleation length it becomes unstable, propagates dynamically and eventually breaks the entire interface, leading to macroscopic sliding. The nucleation process is particularly important because it determines the stress level at which the frictional interface fails, and therefore, the macroscopic friction strength. However, the mechanisms governing nucleation of frictional rupture fronts are still not well understood. Specifically, our knowledge of the nucleation process along a heterogeneous interface remains incomplete. Here, we study the nucleation of localized slip patches on linear slip-weakening interfaces with deterministic and stochastic heterogeneous friction properties. Using numerical simulations, we analyze the process leading to a slip patch of critical size for systems with varying correlation lengths of the local friction strength. Our deterministic interface model reveals that the growth of the critical nucleation patch at interfaces with small correlation lengths is non smooth due to the coalescence of neighboring slip patches. Existing analytical solutions do not account for this effect, which leads to an overestimation of global interface strength. Conversely, when the correlation length is large, the growth of the slip patch is continuous and our simulations match the analytical solution. Furthermore, nucleation by coalescence is also observed on stochastic interfaces with small correlation length. In this case, the applied load for a given slip patch size is a random variable. We show that its expectation follows a logistic function, which allows us to predict the strength of the interface well before failure occurs. Our model and observations provide new understanding of the nucleation process and its effect on the static frictional strength.

Citation

Schär, S., Albertini, G., & Kammer, D. S. (2021). Nucleation of frictional sliding by coalescence of microslip. International Journal of Solids and Structures, 225, Article 111059. https://doi.org/10.1016/j.ijsolstr.2021.111059

• Journal Article Type: Article
• Acceptance Date: Apr 16, 2021
• Online Publication Date: May 10, 2021
• Publication Date: Aug 15, 2021
• Deposit Date: Aug 7, 2023
• Publicly Available Date: Aug 14, 2023
• Journal: International Journal of Solids and Structures
• Print ISSN: 0020-7683
• Electronic ISSN: 1879-2146
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 225
• Article Number: 111059
• DOI: https://doi.org/10.1016/j.ijsolstr.2021.111059
• Public URL: https://nottingham-repository.worktribe.com/output/24059419
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0020768321001499?via%3Dihub