title: Creep and fracture of a protein gel under stress.
abstract: Biomaterials such as protein or polysaccharide gels are known to behave qualitatively as soft solids and to rupture under an external load. Combining optical and ultrasonic imaging to shear rheology we show that the failure scenario of a protein gel is reminiscent of brittle solids: after a primary creep regime characterized by a power-law behavior whose exponent is fully accounted for by linear viscoelasticity, fractures nucleate and grow logarithmically perpendicularly to shear, up to the sudden rupture of the gel. A single equation accounting for those two successive processes nicely captures the full rheological response. The failure time follows a decreasing power law with the applied shear stress, similar to the Basquin law of fatigue for solids. These results are in excellent agreement with recent fiber-bundle models that include damage accumulation on elastic fibers and exemplify protein gels as model, brittlelike soft solids.
authors.affiliation: Université de Lyon, Laboratoire de Physique, École Normale Supérieure de Lyon, CNRS UMR 5672, 46 Allée d'Italie, 69364 Lyon cedex 07, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Leocmach
authors.affiliation: Université de Lyon, Laboratoire de Physique, École Normale Supérieure de Lyon, CNRS UMR 5672, 46 Allée d'Italie, 69364 Lyon cedex 07, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Perge
authors.affiliation: Centre de Recherche Paul Pascal, CNRS UPR 8641 - 115 avenue Schweitzer, 33600 Pessac, France.
authors.forename: Thibaut
authors.initials: T
authors.lastname: Divoux
authors.affiliation: Université de Lyon, Laboratoire de Physique, École Normale Supérieure de Lyon, CNRS UMR 5672, 46 Allée d'Italie, 69364 Lyon cedex 07, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Manneville
mesh_terms: D002364:Caseins / Q000737:chemistry; D005782:Gels / Q000737:chemistry*; D008956:Models, Chemical; D055095:Optics and Photonics / Q000379:methods; D011134:Polysaccharides / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D012212:Rheology; D033081:Shear Strength; D014465:Ultrasonics / Q000379:methods
chemical_list: D002364:Caseins; D005782:Gels; D011134:Polysaccharides; D011506:Proteins