Crack front dynamics: the interplay of singular geometry and crack instabilities

Abstract

When fast cracks become unstable to microscopic branching (micro-branching), fracture no longer occurs in an effective 2D medium. We follow in-plane crack front dynamics via real-time measurements in brittle gels as micro-branching unfolds and progresses. We first show that {\em spatially local} energy balance quantitatively describes crack dynamics, even when translational invariance is badly broken. Furthermore, our results explain micro-branch dynamics; why micro-branches form along spatially localized chains and how finite-time formation of cusps along the crack front leads to their death.

arXiv comment8 pages, 4 figures + supplementary

References in corpus (12)

• Crackling dynamics in material failure as the signature of a self-organized dynamic phase transition
• Dynamics and Instabilities of Planar Tensile Cracks in Heterogeneous Media
• Toughening and asymmetry in peeling of heterogeneous adhesives
• Dynamics of Simple Cracks
• Crack Front Waves and the dynamics of a rapidly moving crack
• Brittle/quasi-brittle transition in dynamic fracture: An energetic signature
• Fracture Roughness Scaling: a case study on planar cracks
• Understanding fast macroscale fracture from microcrack post mortem patterns
• Quantitative prediction of effective toughness at random heterogeneous interfaces
• Crack front échelon instability in mixed mode fracture of a strongly nonlinear elastic solid
• Finite size effects on crack front pinning at heterogeneous planar interfaces: Experimental, finite elements and perturbation approaches
• Dynamic stability of crack fronts: Out-of-plane corrugations

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• Long-range interactions in the avalanches of elastic interfaces
• 3D-2D transition in mode-I fracture microbranching in a perturbed hexagonal close-packed lattice
• Self-Similar Cusp Formation in Thin Liquid Films By Runaway Thermocapillary Forces