Effective Toughness of Heterogeneous Materials with Rate-Dependent Fracture Energy

Gabriele Albertini (1, 2) , Mathias Lebihain (3, 4) , François Hild (5) , Laurent Ponson (4) , David S Kammer (2)

1 ETH Zürich - Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich]
2 Cornell University [New York]
3 NAVIER UMR 8205 - Laboratoire Navier
4 DALEMBERT - Institut Jean Le Rond d'Alembert
5 LMT - Laboratoire de mécanique et technologie

We investigate dynamic fracture of heterogeneous materials experimentally by measuring displacement fields as a rupture propagates through a periodic array of obstacles of controlled fracture energy. Our measurements demonstrate the applicability of the classical equation of motion of cracks at a discontinuity of fracture energy: the crack speed jumps at the entrance and exit of an obstacle, as predicted by the crack-tip energy balance within the brittle fracture framework. The speed jump amplitude is governed by the fracture energy contrast and by the combination of rate-dependency of fracture energy and inertia of the medium, which allows the crack to cross a fracture energy discontinuity at constant energy release rate. This discontinuous dynamics and the rate-dependence cause higher effective toughness, which governs the coarse-grained behavior of these cracks.

Domaines: Mécanique des matériaux [physics.class-ph]

Gabriele Albertini, Mathias Lebihain, François Hild, Laurent Ponson, David S Kammer. Effective Toughness of Heterogeneous Materials with Rate-Dependent Fracture Energy. Physical Review Letters, 2021, 127 (3), ⟨10.1103/PhysRevLett.127.035501⟩. ⟨hal-03358024⟩