Shear band propagation from a crack tip

• Published in: Journal of the mechanics and physics of solids 2003-11, Vol.51 (11), p.1903-1922
• Main Authors: Zhang, Z., Clifton, R.J.
• Format: Article
• Language: English
• Subjects: Applied sciences; Crack tip plasticity; Dynamic fracture; Exact sciences and technology; Fracture mechanics (crack, fatigue, damage...); Fracture mechanics, fatigue and cracks; Fractures; Fundamental areas of phenomenology (including applications); Inelasticity (thermoplasticity, viscoplasticity...); Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metallic materials; Metals. Metallurgy; Physics; Plate impact; Solid mechanics; Stress waves; Structural and continuum mechanics; Viscoelasticity, plasticity, viscoplasticity
• ISSN: 0022-5096
• DOI: 10.1016/j.jmps.2003.09.027

Results are reported for pressure-shear plate impact experiments designed to study the competition between dynamic shear fracture and dynamic shear band formation for a crack subjected to plane wave loading in Mode III. Experiments showing the propagation of a shear band ahead of the main crack are analyzed by using methods developed previously by others for the diffraction of an elastic shear wave by a semi-infinite crack. Based on measured, room-temperature flow stresses, the predicted speed of propagation of the tip of the band is found to be substantially less than that corresponding to the measured extension of the shear band in the experiments. Possible reasons for differences between predicted and measured shear band speeds are discussed. Reduced shearing resistance in the shear band, presumably due to thermal softening, is viewed as the likely explanation for the relatively long shear bands observed.