Dual Role for Heterogeneity in Dynamic Fracture

Abstract

We approach the problem of heterogeneous dynamic fracture by considering spatiotemporal perturbations to planar crack fronts. Front propagation is governed by local energy balance between the elastic energy per unit area available to fracture, G, and the dissipation in creating new surfaces. G is known analytically as a perturbation series in the crack front fluctuation. For dissipation that monotonically increases with the crack speed, we derive an equation of motion for crack fronts that is second-order accurate. In the linear order, heterogeneity does not change the net speed of fracture. In the second order, nonlinear interactions of the front and the heterogeneous landscape populate an intermediate-scale fluctuation spectrum. We find that, when dissipation weakly grows with velocity, nonlinearities globally amplify dissipation and reduce the crack speed. Strong velocity dependence, however, mitigates toughening effects and may facilitate fracture.

9 pages, 7 figures

References in corpus (19)

• Dynamic Fracture in Single Crystal Silicon
• Dynamics and Instabilities of Planar Tensile Cracks in Heterogeneous Media
• Toughening and asymmetry in peeling of heterogeneous adhesives
• Can crack front waves explain the roughness of cracks ?
• Effective toughness of heterogeneous brittle materials
• Theory of dynamic crack branching in brittle materials
• Crack Front Segmentation and Facet Coarsening in Mixed-Mode Fracture
• From microstructural features to effective toughness in disordered brittle solids
• Fractographic aspects of crack branching instability using a phase field model
• Depinning dynamics of crack fronts
• Effective toughness of heterogeneous materials with rate-dependent fracture energy
• How hidden 3D structure within crack fronts reveals energy balance
• Quenched disorder and instability control dynamic fracture in three dimensions
• Uniqueness of the thermodynamic limit for driven disordered elastic interfaces
• Experimental evidence of seismic ruptures initiated by aseismic slip
• Size effects in the toughening of brittle materials by heterogeneities: a non-linear analysis of front deformations
• The dynamics of crack front waves in 3D material failure
• A multiple scales approach to crack front waves
• A comprehensive study of nonlinear perturbations in the dynamics of planar crack fronts