A Finite Element Analysis of Crack Initiation and Propagation in a Notched Disk Submitted to Rolling Contact Fatigue

1998 ◽  
Vol 120 (3) ◽  
pp. 436-441 ◽  
Author(s):  
V. Bordi ◽  
Ch. Dorier ◽  
B. Villechaise
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Crack Initiation ◽  
Crack Growth ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Crack Initiation And Propagation ◽  
Element Analysis ◽  
Initiation And Propagation

A finite element model has been developed to predict crack initiation and propagation in a notched disk submitted to rolling contact fatigue. The aim of this study is to validate the model with experimental results obtained by tests carried out on a two-disk machine. First, a three-dimensional finite element analysis is performed. A unidimensional equivalent damage stress is calculated by applying a plastic criterion in an attempt to estimate the damage location and the time necessary to initiate cracks from the notches. Then a two-dimensional calculation based on linear fracture mechanics is conducted to determine mixed mode stress intensity factors at the tip of a crack initiated from the notch. Several crack growth criteria are used to evaluate crack growth direction and rate. Numerical results are in good agreement with experimental ones.

scholarly journals Observation of Flaking Process in Rolling Contact Fatigue by Laminography Using Ultra-bright Synchrotron Radiation

2018 ◽  
Vol 165 ◽  
pp. 11002
Author(s):  
Yoshikazu Nakai ◽  
Daiki Shiozawa ◽  
Shoichi Kikuch ◽  
Hitoshi Saito ◽  
Takashi Nishina ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Crack Initiation ◽  
Rolling Contact Fatigue ◽  
Rolling Direction ◽  
Contact Fatigue ◽  
Critical Length ◽  
Rolling Contact ◽  
Crack Initiation And Propagation ◽  
Initiation And Propagation ◽  
Damage Process

The flaking failure in rolling contact fatigue (RCF) results from crack initiation and propagation has been believed to originate from non-metallic inclusions located beneath the surface. With conventional microscopies, however, damage process in the internal region of materials could not be observed, then RCF crack initiation and propagation behaviours were observed by using synchrotron radiation computed laminography (SRCL) in the brightest synchrotron facility in Japan, and the effect of the inclusion orientation on the RCF property was examined. In our previous studies, crack initiation and propagation behaviours caused by extended MnS inclusions distributed in depth or transverse (width) direction was observed by the SRCL. In the present study, the fracture mechanism under RCF was discussed on specimens with MnS inclusions distributed in the rolling direction. As a result, vertical cracks were initiated on the surface, parallel to the ball-rolling direction in specimens. The crack propagation direction was then changed perpendicular to the rolling direction. Thereafter, similar with our previous studies, vertical cracks caused the horizontal cracks beneath the surface, when the vertical cracks reached to a critical length. The ratio of the vertical crack initiation life to the flaking life was higher than specimens with other inclusion orientation.

scholarly journals Implementation of a damage calculation in a numerical wheel-rail contact simulation

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Christian Buzzi ◽  
◽  
Andreas Dutzler ◽  
Martin Leitner ◽  
◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Great Distance ◽  
Rolling Contact ◽  
Local Damage ◽  
Post Processing ◽  
Element Analysis ◽  
Finite Element Software

Railways can transport cargo and persons a great distance. The combination of high axle loads, and the rigid wheels and rails made of steel results in high stresses at the wheel-rail contact. These high stresses cause rolling contact fatigue. To prevent and to forecast the rolling contact fatigue, the knowledge of the stresses and their effect on the local damage are important. One possible way to achieve results of the stresses is based on a finite element analysis. The calculation of the rolling contact fatigue is conducted subsequently. This paper will present one possibility to implement the damage calculation into a finite element software and use the post-processing to enable a fast assessment of rolling contact fatigue on the surface and the adjacent volume of a rail.

Investigation of Crack Initiation and Propagation during Rolling Contact Fatigue of SUJ2 Steel Bearings Using a Newly Developed One-Point Testing Machine

2011 ◽  
Vol 418-420 ◽  
pp. 1613-1617 ◽  
Author(s):  
Justyna Rozwadowska ◽  
Katsuyuki Kida ◽  
Edson Costa Santos ◽  
Takashi Honda ◽  
Hitonobu Koike ◽  
...  
Keyword(s):  
Crack Initiation ◽  
Rolling Contact Fatigue ◽  
Testing Machine ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
X Ray Diffraction ◽  
Crack Initiation And Propagation ◽  
New Device ◽  
Initiation And Propagation ◽  
Laser Confocal Microscope

An innovative type of one-point rolling contact fatigue (RCF) machine was developed in order to investigate crack initiation and propagation in metals. The microstructural changes and propagation of subsurface cracks during rolling contact in specimens tested by using the new device were studied by laser confocal microscope and X-ray diffraction. It was shown that this new method presents several important advantages compared to the conventional thrust type RCF machines.

Microstructure Features and Contact Fatigue Crack Growth on Rail

2010 ◽  
Vol 654-656 ◽  
pp. 2491-2494
Author(s):  
Jung Won Seo ◽  
Seok Jin Kwon ◽  
Hyun Kyu Jun ◽  
Dong Hyung Lee
Keyword(s):  
Fatigue Crack ◽  
Crack Growth ◽  
Rolling Contact Fatigue ◽  
Fatigue Crack Initiation ◽  
Contact Fatigue ◽  
Fe Analysis ◽  
Rolling Contact ◽  
Crack Initiation And Propagation ◽  
Loss Of Life ◽  
Initiation And Propagation

Rolling Contact Fatigue (RCF) damage on the surface of rails such a head check, squats is a growing problem. Since rail fractures can cause derailment with loss of life and property, the understanding of rail fracture mechanism is important for reducing damages on the rail surface. In this study, we have investigated RCF damage, fatigue growth and fracture surface morphology on the surface of broken rail using failure analysis and finite element (FE) analysis. The investigation indicates that the crack grows at about 20° to the depth of 8mm from the surface and branches into two cracks. One crack propagates downward at about 47°, the other propagates upward. Since the crack growth rate of the downward crack was faster than that of upward crack, rail eventually was broken. Since the downward branches lead to fracture of the rail, they are more dangerous to the integrity of rails. It has been observed that White Etching Layer (WEL) occurs within the surface of broken rail. It was found that the fatigue crack initiation and propagation was accelerated by WEL.

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