From fractographic observations of specimens that have failed due to rolling contact fatigue, it has been concluded that the first stage of damage is the formation of mode II fatigue cracks parallel to the contact surface due to the cyclic shear stress component of the contact stress. Although these initial subsurface cracks, in both metals and ceramics, are produced in a direction parallel to the cyclic shear stress, cracks eventually grow in a direction close to the plane of the maximum tensile stress if we apply a simple mode II loading to them. The difference between crack growth in simple mode II loading and crack growth due to rolling contact fatigue is, we suppose, whether or not there is a superimposed compressive stress. Based on this hypothesis, we developed an apparatus to obtain the intrinsic characteristics of mode II fatigue crack growth, and developed a simplified model of subsurface crack growth due to rolling contact fatigue. Some results in terms of da/dN versus ΔK IE relations have been obtained using this apparatus on specimens of steel and aluminum alloys. Fractographs of the mode II fatigue fracture surfaces of the various materials are also provided.
[1]
A. R. Rosenfield,et al.
A fracture mechanics approach to wear
,
1980
.
[2]
K. Johnson,et al.
Mode II stress intensity factors for a crack parallel to the surface of an elastic half-space subjected to a moving point load
,
1985
.
[3]
Leon M Keer,et al.
SUBSURFACE AND SURFACE CRACKING DUE TO HERTZIAN CONTACT.
,
1982
.
[4]
K. Johnson.
Contact Mechanics: Frontmatter
,
1985
.
[5]
M. Kaneta,et al.
Analysis of Surface Crack Propagation in Lubricated Rolling Contact
,
1985
.
[6]
Y. Murakami.
Stress Intensity Factors Handbook
,
2006
.
[7]
D. A. Hills,et al.
On the application of fracture mechanics to wear
,
1979
.
[8]
Nam P. Suh,et al.
Mechanics of crack propagation in delamination wear
,
1977
.
[9]
Anthony G. Evans,et al.
Fatigue in ceramics
,
1980
.