An evaluation of the fatigue crack resistance of human dentin was conducted to identify the degree of degradation that arises with aging and the dependency on tubule orientation. Fatigue crack growth was achieved in specimens of coronal dentin through application of Mode I cyclic loading and over clinically relevant lengths (0 ≤ a ≤ 2 mm). The study considered two directions of cyclic crack gro...

An infinite elastic medium with a planar crack is considered. The crack is subjected to the pressure of fluid injected at a point on the crack surface. Description of the crack growth is based on the lubrication equation (balance of the injected fluid and the crack volume), the equation for crack opening caused by fluid pressure on the crack surface, the Poiseuille equation related local fluid ...

The initial stage of fretting fatigue crack growth is significantly influenced by tangential force induced by fretting action along the contact surface where a mixed-mode crack growth is involved. Fretting crack behavior of aluminum alloy 2024 was studied, taking into account the problem of contact asperities. Finite element was used for the determination of the stress field near the contact su...

Recent theoretical results on elastic-plastic planestrain crack growth an~ reviewed and experimental results for crack growth in a 4140 steel are discussed in terms of the theoretical concepts. The theory is based on a recent asymptotic analysis of crack surface opening and strain distributions at a quasistatically advancing crack tip in an ideally plastic solid. The analysis is incomplete in t...

Vibration energies generated by laser irradiation to a plate with a crack were calculated by the semi-analytical finite element method to elucidate the principle of defect imaging using a scanning laser source. For normal incidence in the ablation regime, the incident energy increases when the incident source is located in the vicinity of the crack, owing to the effect of the non-propagating A1...

Despite decades of study, the atomic-scale mechanisms of fatigue crack growth remain elusive. Here we use the coupled atomistic–discrete dislocation method, a multiscale simulation method, to examine the influence of dislocation glide resistance on near-threshold fatigue crack growth in an aluminum alloy. The simulations indicate that the threshold increases with an increase in dislocation glid...

in the last decade, decrease of the wear rate, increase in the axel load, and the velocity of the trains have changed the main damage mechanism of railway wheels from wear to rolling contact fatigue (rcf). rcf may lead to surface and subsurface cracks. the interaction between wear and rcf, removes the surface cracks, but the subsurface crack propagate gradually, and may lead to deeper and more ...

An assessment of the effects of microstructure on room temperature fatigue threshold and crack propagation behaviour has been carried out on microstructural variants of U720Li, i.e. as-received U720Li, U720Li-LG (large grain variant) and U720Li-LP (large intragranular coherent γ′ variant). Fatigue tests were carried out at room temperature using a 20Hz sinusoidal cycling waveform at an Rratio=0...

In this paper, the stress intensity factor (SIF) variations along an arbitrarily developing crack front, the non-planar fatigue-crack growth patterns, and the fatigue life of a round bar with an initially straight-fronted surface crack, are studied by employing the 3D symmetric Galerkin boundary element method-finite element method (SGBEM-FEM) alternating method. Different loading cases, involv...