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

Abstract

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.

Assessing plastically dissipated energy as a condition for fatigue crack growth

“…For a review pertaining to modeling aspects on the subject, see Solanki et al [35], and more recent work can be found for example in Refs. [36,37]. In our model, the normal, frictionless contact formulation in ABAQUS [38] was employed.…”

Finite element meshes for optimal modelling of plasticity induced crack closure

“…To avoid the locking effect, a selective reduced integration method is used in DD3IMP [44,45]. The optimum values of the numerical parameters of the DD3IMP implicit algorithm have been well established in previous works, concerning the numerical simulation of sheet metal forming processes [46] and PICC [47].…”

Effect of crack closure on non-linear crack tip parameters

“…To avoid the locking effect a selective reduced integration method is used in DD3IMP [87]. The optimum values of the numerical parameters of the DD3IMP implicit algorithm have been well established in previous works, concerning the numerical simulation of sheet metal forming processes [88] and PICC [89].…”