Subsonic and intersonic mode II crack propagation with a rate-dependent cohesive zone

• Published in: Journal of the mechanics and physics of solids 2002-06, Vol.50 (6), p.1231-1268
• Main Authors: Samudrala, O., Huang, Y., Rosakis, A.J.
• Format: Article
• Language: English
• Subjects: A. Dynamic fracture; B. Rate-dependent cohesive law; C. Analytic functions; Crack propagation; Exact sciences and technology; Fracture mechanics (crack, fatigue, damage...); Fracture mechanics, fatigue and cracks; Fundamental areas of phenomenology (including applications); Intersonic speeds; Physics; Solid mechanics; Structural and continuum mechanics
• ISSN: 0022-5096
• DOI: 10.1016/S0022-5096(01)00129-6

A recent experimental study has demonstrated the attainability of intersonic shear crack growth along weak planes in otherwise homogeneous, isotropic, linear elastic solids subjected to remote loading conditions (Rosakis et al., Science 284 (5418) (1999) 1337). The relevant experimental observations are summarized briefly here and the conditions governing the attainment of intersonic crack speeds are examined. Motivated by experimental observations, subsonic and intersonic mode II crack propagation with a rate-dependent cohesive zone is subsequently analyzed. A cohesive law is assumed, wherein the cohesive shear traction is either a constant or varies linearly with the local sliding rate. Complete decohesion is assumed to occur when the crack tip sliding displacement reaches a material-specific critical value. Closed form expressions are obtained for the near-tip fields. With a cohesive zone of finite size, it is found that the dynamic energy release rate is finite through out the intersonic regime. Crack tip stability issues are addressed and favorable speed regimes are identified. The influence of shear strength of the crack plane and of a rate parameter on crack propagation behavior is also investigated. The isochromatic fringe patterns predicted by the analytical solution are compared with the experimental observations of Rosakis et al. (1999) and comments are made on the validity of the proposed model.