Delayed fracture of an inhomogeneous soft solid

Science

Volumn 280, Issue 5361, 1998, Pages 265-267

  Bonn, Daniel ^a   Kellay, Hamid ^a   Prochnow, Michaël ^a   Ben Djemiaa, Karim ^a   Meunier, Jacques ^a  

^a NONE

Author keywords

[No Author keywords available]

Indexed keywords

POLYMER;

ARTICLE; ELASTICITY; ENERGY; MATERIAL STATE; MECHANICAL STRESS; POLYMERIZATION; PRIORITY JOURNAL; SOLID;

EID: 0032502824     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.280.5361.265     Document Type: Article

References (14)

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3. Agarose type XII, I-a, and III-a (denoted as gels 1, 2, and 3) from Sigma was dissolved at 1 weight % in water (Milli-Q-Plus) at 95°C by stirring. Subsequently, the solution was poured into a mold and left for at least 2 hours at 20°C before use. For the three gels, we found E = 75.2, 46.1, and 50.6 kPa. For σ < 50 Pa or frequency f < 10 Hz, the elastic or storage modulus G′ = 22.8, 14.6, and 15.6 kPa, respectively. As expected for a gel, Poisson's ratio ≈ 0.5. The ratio of G′ and the viscous or loss modulus G″ (G′/G″) is between 10 and 13 for the three gels. Rheological measurements were performed on a Reologica Stress-Tech rheometer. For the fracture experiments, a rectangular bar (100 mm × 20 mm × 10 mm) rested on a Teflon-coated surface greased with liquid Vaseline oil, with its ends held in place by two aluminium rods. The middle flexion point moved on an air bearing and was coupled to a force transducer. A small amount of plastic deformation was observed for the largest forces; in the experiments, the force was always kept constant. Plastic deformation due to aging was not observed in the experiments.
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14. We thank M. Adda-Beds for helpful discussions and V. Bergeron (Rhone-Poulenc) for the use of the high-speed camera. Laboratoire de Physique Statistique de l'Ecole Normale Supérieure is Unité de Recherche Associée 1306 of the CNRS, associated with Universities Paris 6 and 7.