THERMOMECHANICAL EFFECTS ON CRACK PROPAGATION IN ROLLING CONTACT FATIGUE FAILURE

2003 ◽  
Vol 26 (6) ◽  
pp. 615-639 ◽  
Author(s):  
Takahito Goshima
Keyword(s):  
Crack Propagation ◽  
Fatigue Failure ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Thermomechanical Effects

Effect of defect length on rolling contact fatigue crack propagation in high strength steel

2015 ◽  
Author(s):  
T. Makino ◽  
Y. Neishi ◽  
D. Shiozawa ◽  
Y. Neishi ◽  
D. Shiozawa ◽  
...  
Keyword(s):  
Crack Propagation ◽  
High Strength Steel ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
High Strength ◽  
Rolling Contact ◽  
Micro Ct ◽  
Middle Line ◽  
Micro Computed Tomography ◽  
Depth Direction

 The objective of the present paper is to clarify the effect of defect length in depth direction on rolling contact fatigue (RCF) crack propagation in high strength steel. RCF test and synchrotron radiation micro computed tomography (SR micro CT) imaging were conducted. In the case of the defect with the 15 ?m diameter, flaking life decreased with increasing defect length. In a comparison of the CT image and the SEM view, the shapes of defects and the locations of the horizontal cracks were almost the same respectively. The mechanism of RCF crack propagation was discussed by finite element (FE) analysis. Defects led to higher tensile residual stress than that without defects in the region where the defect exists. The shear stress range at 0.1 mm in depth on the middle line of the defect and the range of mode II stress intensity factor at the bottom of a vertical crack increased with increasing defect length.

A Predictive Rolling Contact Fatigue Crack Growth Model: Onset of Branching, Direction, and Growth—Role of Dry and Lubricated Conditions on Crack Patterns

2002 ◽  
Vol 124 (4) ◽  
pp. 680-688 ◽  
Author(s):  
M. C. Dubourg ◽  
V. Lamacq
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Interfacial Crack ◽  
Rolling Contact ◽  
Propagation Behavior ◽  
Branch Formation ◽  
Complex Crack ◽  
Crack Growth Model

Complex crack networks are initiated in rails under Rolling Contact Fatigue. This paper attempts to model the RCF crack propagation with a particular emphasis on the branching conditions and the parameters that play a role on them. The numerical tool proposed rests on the combination of the author’s RCF model, Hourlier and Pineau’s criterion for the branch prediction and experimental data and the corresponding models for fatigue crack extension that are derived from a Joint European project. Parametric studies on the influence of (i) residual stresses, (ii) both interfacial crack and wheel/rail contact frictional effects, (iii) neighboring crack are conducted to reach a better understanding of the RC crack propagation behavior and more particularly the branch conditions, i.e., the length of the primary crack prior to branch formation and the branch direction.

A Possible Mechanism for Rail Dark Spot Defects

1998 ◽  
Vol 120 (2) ◽  
pp. 304-309 ◽  
Author(s):  
M. Kaneta ◽  
K. Matsuda ◽  
K. Murakami ◽  
H. Nishikawa
Keyword(s):  
Fracture Mechanics ◽  
Fatigue Failure ◽  
High Speed ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Traction Force ◽  
Rolling Contact ◽  
Dark Spot ◽  
A Posteriori ◽  
Direction Opposite

Rail dark spot defect, also termed squat failure or shelling, which is a kind of rolling contact fatigue failure and occurs frequently on running surfaces of railway rails carrying high speed traffic, is one of the most dangerous rail failures. The dark spot crack is characterized by a principal crack propagating in the direction of traffic and a second crack growing in the direction opposite to traffic. By using a newly developed two-disk machine, the authors have succeeded in reproducing very similar dark spot cracks to those which appear in actual rails. It is found that the dark spot defects are caused by frequent repetitions of dry and wet runnings, and that the traction force plays an important role for the occurrence of the cracks. The principal crack may occur from a tiny pit formed a posteriori on the contacting surface and after that, the second crack is formed by cracks branched from the extended principal crack. It has also been proved experimentally that water is capable of entering the tip of the crack. Furthermore, a possible mechanism for the dark spot cracking has been proposed on the basis of the fracture mechanics approach.

Subsurface Stress Distribution and Failure of PPS Thrust Bearings under Rolling Contact Fatigue in Water

2019 ◽  
Vol 814 ◽  
pp. 152-156 ◽  
Author(s):  
Xiao Chen Shi ◽  
Akihiro Adachi ◽  
Katsuyuki Kida
Keyword(s):  
Fatigue Crack ◽  
Stress Distribution ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Polymer Materials ◽  
Thrust Bearings ◽  
Subsurface Stress

In recent years, environments of bearings and polymer materials have been more and more attractive due to several advantages against ordinary metal material. However, there is still room for the further study about strength of polymer bearings. One of questions is the mechanism of fatigue crack propagation, which is the main cause of the damage of polymer bearings under rolling contact with lubricant, like water. In this study, subsurface stress distribution and failure of PPS thrust bearings under rolling contact fatigue in water are discussed to understand the detail of the crack propagation.

Internal Shear Stress Distribution and Subsurface Cracks of PPS Thrust Bearings under Rolling Contact Fatigue in Water

2020 ◽  
Vol 858 ◽  
pp. 101-105
Author(s):  
Syunsuke Mizozoe ◽  
Katsuyuki Kida
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Crack Propagation ◽  
Contact Stress ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Subsurface Crack ◽  
Thrust Bearings ◽  
Subsurface Cracks

In this study, crack propagation in PPS thrust bearings under rolling contact fatigue (RCF) in water was observed, and relation between subsurface crack and internal shear stress parallel to the surface was investigated. It was found the cause of flaking was subsurface crack. They were evaluated in terms of contact stress and friction between their faces. It was discovered that subsurface cracks distributed around shear stress peak, and flaking failure was dominated by subsurface shear stress.

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