2024/03/26 by Yuri Lubomirsky, Lubomirsky, Yuri, Eran Bouchbinder +1
Physics and Astronomy · #Disordered Systems and Neural Networks (cond-mat.dis-nn) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Pattern Formation and Solitons (nlin.PS) #Quantum chaos and dynamical systems #Random lasers and scattering media #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.2403.17781
openalex publication_date 2024/03/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Cracks develop various surface patterns as they propagate in three-dimensional (3D) materials. Facet formation in nominally tensile (mode-I) fracture emerge in the slow, non-inertial regime and oftentimes takes the form of surface steps. We show that the same phase-field framework that recently shed basic light on dynamic (inertial) tensile fracture in 3D, also gives rise to crack surface steps. Step formation is shown to be an intrinsically nonlinear phenomenon that involves two essential physical ingredients: finite-strength quenched disorder and a small, mesoscopic anti-plane shear (mode-III) loading component (on top of the dominant tensile, mode-I loading component). We quantify the interplay between disorder (both its strength and spatial correlation length) and mesoscopic mode I+III mixity in controlling step formation. Finally, we show that surface steps grow out of the small-scale, background surface roughness and are composed of two overlapping crack segments connected by a bridging crack, in agreement with experiments.