Fracture of a model cohesive granular material

Abstract

We study experimentally the fracture mechanisms of a model cohesive granular medium consisting of glass beads held together by solidified polymer bridges. The elastic response of this material can be controlled by changing the cross-linking of the polymer phase, for example. Here we show that its fracture toughness can be tuned over an order of magnitude by adjusting the stiffness and size of the polymer bridges. We extract a well-defined fracture energy from fracture testing under a range of material preparations. This energy is found to scale linearly with the cross-sectional area of the bridges. Finally, X-ray microcomputed tomography shows that crack propagation is driven by adhesive failure of about one polymer bridge per bead located at the interface, along with microcracks in the vicinity of the failure plane. Our findings provide insight to the fracture mechanisms of this model material, and the mechanical properties of disordered cohesive granular media in general.

References in corpus (7)

• Jamming, Force Chains and Fragile Matter
• Tunable failure: control of rupture through rigidity
• A cohesive granular material with tunable elasticity
• Effect of long-range repulsive Coulomb interactions on packing structure of adhesive particles
• From liquid to solid bonding in cohesive granular media
• Shear shocks in fragile networks
• Interface propagation in fiber bundles: Local, mean-field and intermediate range-dependent statistics

Cited by in corpus (5)

• Failure processes of cemented granular materials
• Strain localization and failure of disordered particle rafts with tunable ductility during tensile deformation
• Role of normal stress in the creep dynamics and failure of a biopolymer gel
• Crossover from viscous fingering to fracturing in cohesive wet granular media: a photoporomechanics study
• Measuring and upscaling micromechanical interactions in a cohesive granular material