Crack front échelon instability in mixed mode fracture of a strongly nonlinear elastic solid

Abstract

Mixed mode (I+III) loading induces segmented crack front échelon structures connected by steps. We study this instability in a highly deformable, strain-hardening material. We find that échelons develop beyond a finite, size-independent mode mixity threshold, markedly growing with energy release rate. They appear via nucleation of localized helical front distortions, and their emergence is the continuation of the mode I cross-hatching instability of gels and rubbers, shifted by the biasing effect of shear. This result, at odds with the direct bifurcation predicted by linear elastic fracture mechanics, can be assigned to the controlling role of elastic nonlinearity.

References in corpus (4)

• Solvent control of crack dynamics in a reversible hydrogel
• Fracture of a biopolymer gel as a viscoplastic disentanglement process
• Magic angles and cross-hatching instability in hydrogel fracture
• Damage mechanisms in the dynamic fracture of nominally brittle polymers

Cited by in corpus (10)

• Crack Front Segmentation and Facet Coarsening in Mixed-Mode Fracture
• Topological defects govern crack front motion and facet formation on broken surfaces
• Crack front dynamics: the interplay of singular geometry and crack instabilities
• How moving cracks in brittle solids choose their path
• How hidden 3D structure within crack fronts reveals energy balance
• How Material Heterogeneity Creates Rough Fractures
• Configurational stability of a crack propagating in a material with mode-dependent fracture energy -- Part II: Drift of fracture facets in mixed-mode I+II+III
• Limitations of the modelling of crack propagating through heterogeneous material using a phase field approach
• Size selection of crack front defects: Multiple fracture-plane interactions and intrinsic lengthscales
• Crack front instabilities under mixed mode loading in three dimensions