Topic
Crack closure
About: Crack closure is a research topic. Over the lifetime, 28157 publications have been published within this topic receiving 588158 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, an underaged, aged, and overaged microstructure of an austenitic Fe-36 at.% Ni-12 at.%. Al alloy was investigated for fatigue crack propagation.
175 citations
TL;DR: In this paper, the micromechanics of failure emanating from machining-induced cracks in brittle materials are investigated and two components of residual stress have been identified: a crack-wedging force due to the plastic zone beneath the strength-controlling machining groove, and a compressive surface layer due to adjacent grooves.
Abstract: The micromechanics of failure emanating from machining-induced cracks in brittle materials is investigated. In situ monitoring of crack response during breaking tests (with use of acoustic wave scattering), strength measurements and post-failure fractography all indicate that the crack response is dominated by residual stresses. Two components of residual stress have been identified: a crack-wedging force due to the plastic zone beneath the strength-controlling machining groove, and a compressive surface layer due to adjacent grooves. The wedging force dominates and causes stable equilibrium crack extension during a breaking test. The implications of the results for non-destructive evaluation of surface damage by acoustic wave scattering is discussed.
175 citations
TL;DR: In this paper, the effect of the stress ratio on near-threshold growth of delamination fatigue cracks was investigated with unidirectional laminates made from Ciba Geigy 914C prepegs (T300/914) and from Toray P305 pre-pegs.
174 citations
TL;DR: In this article, the effects of different constitutive models, including the influence of mean stress relaxation, were investigated in terms of an interaction between residual deformations and crack opening displacements.
174 citations
25 Nov 2008-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the fatigue properties of an extruded AZ31B magnesium alloy were evaluated using strain-controlled push-pull cyclic tests at different total strain amplitudes at room temperature.
Abstract: Fatigue properties of an extruded AZ31B magnesium alloy were evaluated using strain-controlled push–pull cyclic tests at different total strain amplitudes at room temperature. The alloy exhibited an asymmetric sigmoidal-shaped hysteresis loop due to twinning in compression during the unloading phase and detwinning during the loading phase. As the total strain amplitude increased, the asymmetry of hysteresis loops, plastic strain amplitude, mean stress, and stress amplitude increased, while the ratcheting strain and pseudoelastic modulus decreased. As the cyclic deformation progressed at a given total strain amplitude (greater than 0.3%), an abrupt increase in the plastic strain amplitude was observed, representing the onset of fatigue crack initiation. The extent of this increase process, which decreased with increasing total strain amplitude, corresponded to the fatigue crack propagation prior to the final fast failure. Fatigue crack initiation was observed to occur at the specimen surface, and fatigue crack propagation was characterized by typical striations. The smaller spacing of fatigue striations and larger fatigue crack propagation zone at the lower total strain amplitude gave rise to a longer fatigue life. The Coffin–Manson and Basquin's relationships can be used to describe the fatigue lifetime of this alloy.
174 citations