The ranges of the threshold stress intensity factor (SIF), δKIIth and δKIIIth, for small shear-mode cracks in bearing steel are measured using torsional fatigue testing under static compression. The threshold values are described as a function of the crack size and the crack-face interference. In addition, to simplify the evaluation of the shear-mode threshold, a single parameter, Kτ, is introduced to represent the SIF of shear-mode cracks. Moreover, a practical expression for approximating Kτ is proposed on the basis of the area parameter model. Finally, the threshold SIF range δKτth is found to exhibit a dependence on the crack size similar to that of small mode I cracks, i.e., δKτth∝(area)1/3, for the regime of small shear-mode cracks with area values ranging from 0.01 to 1mm.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanical Engineering
- Applied Mathematics