Numerical simulation of plasticity induced crack closure: Identification and discussion of parameters

• Published in: Engineering fracture mechanics 2008-07, Vol.75 (10), p.3101-3120
• Main Authors: Antunes, F.V., Rodrigues, D.M.
• Format: Article
• Language: English
• Subjects: Classical and quantum physics: mechanics and fields; Classical mechanics of continuous media: general mathematical aspects; Elastic–plastic material behaviour; Exact sciences and technology; Finite element analysis; Fracture mechanics (crack, fatigue, damage...); Fundamental areas of phenomenology (including applications); Inelasticity (thermoplasticity, viscoplasticity...); Measurement and testing methods; Middle-crack tension specimen; Numerical parameters; Physics; Plasticity induced crack closure; Solid mechanics; Structural and continuum mechanics
• ISSN: 0013-7944; 1873-7315
• DOI: 10.1016/j.engfracmech.2007.12.009

Numerical studies play a major role in the understanding and prediction of plasticity induced crack closure (PICC). However, the available numerical models can be considered simplifications of reality as they consider discrete crack propagations, relatively high fatigue crack growth rates (FCGR), sharp cracks, and propagation occurring at well-defined loads. Besides, there are a great number of numerical and physical parameters affecting the predictions of PICC. The aim of this paper is to discuss the numerical study of PICC. The numerical parameters affecting the accuracy of the numerical simulations, and the dependent parameters used to characterise the plastic wake and the closure level, are identified. The influence of the radial size of crack front elements and crack propagation is analysed. An extrapolation model is proposed, with excellent results. An intrinsic uncertainty is associated with the number of load cycles between crack increments and the definition of crack closure level. Finally, the effect of the stress ratio ( R) on crack closure level is analysed.