Abstract
A new parameter, which can quantitatively describe fatigue crack propagation, is proposed in this paper. This parameter reflects the cyclic plasticity behaviour near the crack tip, and the resulting built up of layers with the residual plastic deformations on the fatigue crack surfaces. A fatigue crack closure model suitable for an arbitrary applied stress distribution with an arbitrary residual stress distribution based on appropriately modified Dugdale's concept of crack tip plasticity is developed. A re-tensile plastic zone generated (RPG) load, at which the tensile plastic zone starts to develop ahead of a crack tip, is defined. The effective stress intensity factor range is redefined by replacing the crack opening load with the RPG load. This redefined effective stress intensity factor is termed ΔKRPG. When ΔKRPG substitutes for ΔK or the crack opening load based on ΔKeff the "knee" in the threshold region of the crack growth data is not seen any longer. As a result, it is confirmed that a stopping phenomenon of a fatigue crack propagation can be quantitatively and appropriately described without the threshold value such as (ΔK eff)th. It is also confirmed that the proposed crack closure model can provide quantitative estimates of the fatigue life under various loading conditions and in pre-existing residual stress field.
| Original language | English |
|---|---|
| Pages (from-to) | 983-992 |
| Number of pages | 10 |
| Journal | International Journal of Fatigue |
| Volume | 26 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - Sep 1 2004 |
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All Science Journal Classification (ASJC) codes
- Modelling and Simulation
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering
- Industrial and Manufacturing Engineering
Cite this
Fatigue crack propagation for a through thickness crack : A crack propagation law considering cyclic plasticity near the crack tip. / Toyosada, Masahiro; Gotoh, Koji; Niwa, Toshio.
In: International Journal of Fatigue, Vol. 26, No. 9, 01.09.2004, p. 983-992.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Fatigue crack propagation for a through thickness crack
T2 - A crack propagation law considering cyclic plasticity near the crack tip
AU - Toyosada, Masahiro
AU - Gotoh, Koji
AU - Niwa, Toshio
PY - 2004/9/1
Y1 - 2004/9/1
N2 - A new parameter, which can quantitatively describe fatigue crack propagation, is proposed in this paper. This parameter reflects the cyclic plasticity behaviour near the crack tip, and the resulting built up of layers with the residual plastic deformations on the fatigue crack surfaces. A fatigue crack closure model suitable for an arbitrary applied stress distribution with an arbitrary residual stress distribution based on appropriately modified Dugdale's concept of crack tip plasticity is developed. A re-tensile plastic zone generated (RPG) load, at which the tensile plastic zone starts to develop ahead of a crack tip, is defined. The effective stress intensity factor range is redefined by replacing the crack opening load with the RPG load. This redefined effective stress intensity factor is termed ΔKRPG. When ΔKRPG substitutes for ΔK or the crack opening load based on ΔKeff the "knee" in the threshold region of the crack growth data is not seen any longer. As a result, it is confirmed that a stopping phenomenon of a fatigue crack propagation can be quantitatively and appropriately described without the threshold value such as (ΔK eff)th. It is also confirmed that the proposed crack closure model can provide quantitative estimates of the fatigue life under various loading conditions and in pre-existing residual stress field.
AB - A new parameter, which can quantitatively describe fatigue crack propagation, is proposed in this paper. This parameter reflects the cyclic plasticity behaviour near the crack tip, and the resulting built up of layers with the residual plastic deformations on the fatigue crack surfaces. A fatigue crack closure model suitable for an arbitrary applied stress distribution with an arbitrary residual stress distribution based on appropriately modified Dugdale's concept of crack tip plasticity is developed. A re-tensile plastic zone generated (RPG) load, at which the tensile plastic zone starts to develop ahead of a crack tip, is defined. The effective stress intensity factor range is redefined by replacing the crack opening load with the RPG load. This redefined effective stress intensity factor is termed ΔKRPG. When ΔKRPG substitutes for ΔK or the crack opening load based on ΔKeff the "knee" in the threshold region of the crack growth data is not seen any longer. As a result, it is confirmed that a stopping phenomenon of a fatigue crack propagation can be quantitatively and appropriately described without the threshold value such as (ΔK eff)th. It is also confirmed that the proposed crack closure model can provide quantitative estimates of the fatigue life under various loading conditions and in pre-existing residual stress field.
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UR - http://www.scopus.com/inward/citedby.url?scp=2942708221&partnerID=8YFLogxK
U2 - 10.1016/j.ijfatigue.2003.12.006
DO - 10.1016/j.ijfatigue.2003.12.006
M3 - Article
VL - 26
SP - 983
EP - 992
JO - International Journal of Fatigue
JF - International Journal of Fatigue
SN - 0142-1123
IS - 9
ER -