A numerical investigation on the effect of an overload on fatigue crack opening and closure behaviour

Abstract

The effect of a superimposed single tensile overload or a compressive overload in a block of constant‐amplitude cycles on the crack opening and closing stresses is investigated using an elastic–plastic finite element analysis. The results obtained are in basic agreement with the experimental observations. Following an applied tensile overload cycle, the crack opening and closing stresses increase instantaneously, while the imposition of a compressive overload cycle results in a small decrease of the crack opening and closing stresses. A detailed discussion of the residual stress and strain patterns caused by the plastic deformation during the overload cycle and the corresponding crack profiles is included. The main governing mechanism resulting in the change of crack growth due to an overload is pointed out.

Variable amplitude fatigue crack growth behavior — a short overview

“…Their results showed qualitative agreement with experimental results, although the FE meshes used were coarse and do not satisfy mesh refinement criteria suggested later [126,127], and the crack growth lengths with the models were small. In the recent years, many reports have been put forward to understand single overload transients using both 2D [128][129][130][131][132][133][134] and 3D [130,135] FE models. FE studies for cracks subjected to double and periodic tensile overloads have been reported by [13,92].…”

The effect of material model in describing mechanism of plasticity-induced crack closure under variable cyclic loading

“…Figure 1(a) shows a schematic of the growth retardation process. This mechanism implies that the post-overload retardation effect would be immediate with no transient acceleration (Skorupa (1999), McEvily and Ishihara (2002), Borrego et al (2003)), except for an instantaneous crack growth acceleration upon overload application (Ellyin and Wu (1999), Ward-Close and Ritchie (1988)). …”

“…Therefore, K eff,OL > K eff,before OL , the driving force for crack growth is increased; thus, an acceleration in growth rate occurs. However, it should also be noted that the acceleration may be reduced by ductile crack growth increment (DCGI) induced closure resulting from the applied overload (Ellyin and Wu (1999)). …”

Investigation of Mesh Sensitivity Influence to Determine Crack Characteristic by Finite Element Methods

“…The tetrahedral elements are available as first-(linear) and second-(quadratic) order approximations, where the hexahedral elements are restricted to firstorder in the XFEM model [29]. Since XFEM method, do not need to update the mesh to match the current geometry of the discontinuity, it is a useful method to simulate crack propagation.…”