Fatigue growth threshold of small cracks

Tanaka, Keisuke; Nakai, Yoshikazu; Yamashita, Masaaki

doi:10.1007/bf00033345

Cited by 328 publications

(25 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such a relationship is depicted in Figure 3. When the inclusion size is small, those inclusions have no harmful effect on the fatigue strength, as reported by many researchers [24,25]. From this point of view, if the critical small size is assumed as ρ = 3 µm in this study, the upper bound of the fatigue strength given by Equation (3) becomes σ w9 = 1060 MPa, as indicated in Figure 3.…”

Section: Experimental Fatigue Test Data Referred In This Studysupporting

confidence: 58%

Proposal of a Probabilistic Model on Rotating Bending Fatigue Property of a Bearing Steel in a Very High Cycle Regime

et al. 2021

View full text Add to dashboard Cite

In S-N diagrams for high strength steels, the duplex S-N curves for surface-initiated failure and interior inclusion-initiated failure were usually confirmed in the very high cycle regime. This trend is more distinct in the loading type of rotating bending, due to the stress distribution across the section. In the case of interior failure mode, the fish-eye is usually observed on the fracture surface and an inclusion is also observed at the center of the fish-eye. In the present work, the authors attempted to construct a probabilistic model on the statistical fatigue property in the interior failure mode, based on the distribution characteristics of the location and the size of the interior inclusion at the crack initiation site. Thus, the P-S-N characteristics of the bearing steel (SUJ2) in the very high cycle regime were successfully explained.

show abstract

Section: Experimental Fatigue Test Data Referred In This Studysupporting

confidence: 58%

Proposal of a Probabilistic Model on Rotating Bending Fatigue Property of a Bearing Steel in a Very High Cycle Regime

et al. 2021

View full text Add to dashboard Cite

show abstract

“…6(b) shows a distinct "V" shape preceding the crack tip, with one example indicated by the red arrows, which may be a blunted crack or plastic hinge caused by local thinning and deformation from strain fields ahead of the crack tip [45][46][47], or movement of material through dislocation emission and absorption between nearby grain boundaries and the advancing crack tip [12]. The plastic deformation zone was also confined to the grains located immediately in front of the crack tip, indicating that possible slip transfer was limited by factors such as grain boundary character, slip system orientation, and angle of crack deflection [31,[48][49][50][51].…”

Section: Resultsmentioning

confidence: 99%

In Situ High-Cycle Fatigue Reveals Importance of Grain Boundary Structure in Nanocrystalline Cu-Zr

Schuler¹,

Barr²,

Heckman³

et al. 2019

JOM

View full text Add to dashboard Cite

Nanocrystalline metals typically have high fatigue strengths, but low resistance to crack propagation. Amorphous intergranular films are disordered grain boundary complexions that have been shown to delay crack nucleation and slow crack propagation during monotonic loading by diffusing grain boundary strain concentrations, suggesting they may also be beneficial for fatigue properties. To probe this hypothesis, in situ transmission electron microscopy fatigue cycling is performed on Cu-1 at.% Zr thin films thermally treated to have either only ordered grain boundaries or to contain amorphous intergranular films. The sample with only ordered grain boundaries experienced grain coarsening at crack initiation followed by unsteady crack propagation and extensive nanocracking, whereas the sample containing amorphous intergranular films had no grain coarsening at crack initiation followed by steady crack propagation and distributed plastic activity. Microstructural design for control of these behaviors through simple thermal treatments can allow for the improvement of nanocrystalline metal fatigue toughness.

show abstract

“…The first experimental data being analysed concern the fatigue threshold condition for mild steel . Such data are related to ferritic and pearlitic steels with carbon content equal to 0.20%, and grain size d of the ferritic phase equal to 7.8 μm (small‐size grain) and 55 μm (large‐size grain), respectively (the experimental threshold SI ranges related to each crack length are normalized with respect to the corresponding threshold SI range for long cracks and, in turn, the crack length is normalized with respect to the grain size).…”

Section: Applications To Fatigue Threshold and Fatigue Crack Growth R...mentioning

confidence: 99%

“…Figure 10 shows the experimental data related to fatigue crack growth rate against the normalized crack length a/d together with the corresponding theoretical curve of the kinked crack model. The experimental data refer to selected propagating and non-propagating crack cases for different stress levels, whereas the theoretical curve is described by Equation (38) Finally, some experimental data concerning fatigue crack growth in the Paris regime are analysed. 24 Such data are related to fatigue crack propagation in single edge-cracked three-point bend specimens made of normal-strength (NS) plain concrete 40 and high-strength (HS) plain concrete.…”

Section: Applications To Fatigue Threshold and Fatigue Crack Growth R...mentioning

confidence: 99%

Crack morphology models for fracture toughness and fatigue strength analysis

Carpinteri

Spagnoli

Terzano

2019

Fatigue Fract Eng Mat Struct

View full text Add to dashboard Cite

Planar cracks represent an approximation, largely adopted in fracture mechanics and fatigue problems, of the physical reality, where cracks feature complex geometric morphologies related to material microstructure, residual stresses, material properties dispersions and so on. In the present paper, firstly a model to describe the influence of roughness and friction of the crack surfaces is reviewed in relation to the resulting near‐tip stress field and the fracture resistance under monotonic loading. Such a model is based on the Distributed Dislocation Technique, and considers a periodic profile of the crack. Then, some approximate theoretical models describing periodically kinked cracks are reviewed in their application to the estimation of fatigue strength of materials. In particular, the influence of crack path meandering on fatigue propagation is analysed by modelling the crack profile as a piecewise linear periodic curve in two dimensions. The same type of model is discussed within the framework of self‐similar fractal geometries. In the paper, emphasis is given to the effect of crack size on the fracture resistance and fatigue strength, where such an effect depends on the ratio between the characteristic length of the crack morphology and the nominal length of the crack itself.

show abstract

Fatigue growth threshold of small cracks

Cited by 328 publications

References 12 publications

Proposal of a Probabilistic Model on Rotating Bending Fatigue Property of a Bearing Steel in a Very High Cycle Regime

Proposal of a Probabilistic Model on Rotating Bending Fatigue Property of a Bearing Steel in a Very High Cycle Regime

In Situ High-Cycle Fatigue Reveals Importance of Grain Boundary Structure in Nanocrystalline Cu-Zr

Crack morphology models for fracture toughness and fatigue strength analysis

Contact Info

Product

Resources

About