5:15 PM - 6:45 PM
[SCG44-P16] Yielding and fracture of a complex fluid under unsteady shear rate
The flow-to-fracture transition, such as slow earthquakes and fast rupture of plate boundary earthquakes, and brittle and ductile fracturing of magma in volcanic eruptions, is an important and unexplored phenomenon in solid earth science.
In volcanology, the glass transition is considered to appear at high strain rates and control the brittle fracture of magma. In physics, on the other hand, the glass transition is more frequently associated with the appearance of yield strength at low strain rates. To bridge this discrepancy and establish the fracture mechanics for complex fluids, we experimentally show the contrasting flow/fracture behaviors of Maxwell-type viscoelastic fluid and Bingham-type yield-strength fluid.
As a viscoelastic sample, we synthesized the warm-like micellar solution and solution of the synthetic fine saponite clay. After viscoelastic measurements on a cone plate with a diameter of 25 mm using a rotary rheometer, shear tests were conducted increasing the shear rate at a given rate (0.1, 1, 10, 100 s-2).
Our results show that the evolution from flow to fracture is not explained by the conventional diagram for the prescribed strain rate. Brittle fracture and yielding of fluids are determined by critical stress or strain, like in elastic solid. We emphasize that the observation of elasticity at small strain is not sufficient to infer that fluid can generate brittle fractures.
In volcanology, the glass transition is considered to appear at high strain rates and control the brittle fracture of magma. In physics, on the other hand, the glass transition is more frequently associated with the appearance of yield strength at low strain rates. To bridge this discrepancy and establish the fracture mechanics for complex fluids, we experimentally show the contrasting flow/fracture behaviors of Maxwell-type viscoelastic fluid and Bingham-type yield-strength fluid.
As a viscoelastic sample, we synthesized the warm-like micellar solution and solution of the synthetic fine saponite clay. After viscoelastic measurements on a cone plate with a diameter of 25 mm using a rotary rheometer, shear tests were conducted increasing the shear rate at a given rate (0.1, 1, 10, 100 s-2).
Our results show that the evolution from flow to fracture is not explained by the conventional diagram for the prescribed strain rate. Brittle fracture and yielding of fluids are determined by critical stress or strain, like in elastic solid. We emphasize that the observation of elasticity at small strain is not sufficient to infer that fluid can generate brittle fractures.