Sat, 19 Jul 2008 02:59:24 BST CiteULike: dchen's library [874 articles] http://www.citeulike.org/user/dchen/article/2759114 CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dchen/article/2759114 <i>Physical Review Letters, Vol. 100, No. 17. (2008)</i><br /><br />The full 2D analysis of roughness profiles of fracture surfaces resulting from quasistatic crack propagation in gelatin gels reveals an original behavior characterized by (i) strong anisotropy with maximum roughness at V-independent symmetry-preserving angles and (ii) a subcritical instability leading, below a critical velocity, to a cross-hatched regime due to straight macrosteps drifting at the same magic angles and nucleated on crack-pinning network inhomogeneities. Step height values are determined by the width of the strain-hardened zone, governed by the elastic crack blunting characteristic of soft solids with breaking stresses much larger than low strain moduli. Magic Angles and Cross-Hatching Instability in Hydrogel Fracture T Baumberger C Caroli D Martina O Ronsin doi:10.1103/PhysRevLett.100.178303 Physical Review Letters, Vol. 100, No. 17. (2008) 2008-05-05T20:13:26-00:00 2008 Physical Review Letters 100 17 APS defect gel interface structure