Prediction of Fatigue Crack Growth Path and Fatigue Life due to Repeated Hertzian Rolling Contact

The main objective of this work was to present a numerical modelling of crack growth path in linear elastic materials under mixed-mode loadings, as well as to study the effect of presence of a hole on fatigue crack propagation and fatigue life in a modified compact tension specimen under constant amplitude loading condition. The ANSYS Mechanical APDL 19.2 is implemented for accurate prediction of the crack propagation paths and the associated fatigue life under constant amplitude loading conditions using a new feature in ANSYS which is the smart crack growth technique. The Paris law model has been employed for the evaluation of the mixed-mode fatigue life for the modified compact tension specimen (MCTS) with different configuration of MCTS under the linear elastic fracture mechanics (LEFM) assumption. The approach involves accurate evaluation of stress intensity factors (SIFs), path of crack growth and a fatigue life evaluation through an incremental crack extension analysis. Fatigue crack growth results indicate that the fatigue crack has always been attracted to the hole, so either it can only curve its path and propagate towards the hole, or it can only float from the hole and grow further once the hole has been lost. In terms of trajectories of crack propagation under mixed-mode load conditions, the results of this study are validated with several crack propagation experiments published in literature showing the similar observations. Accurate results of the predicted fatigue life were achieved compared to the two-dimensional data performed by other researchers.

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A study on the prediction of a fatigue crack growth path (1st report, A preliminary study)

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A ◽

10.1299/kikaia.52.2139 ◽

1986 ◽

Vol 52 (481) ◽

pp. 2139-2142 ◽

Cited By ~ 2

Author(s):

Satoshi FUJIWARA ◽

Takashi MIYAZONO ◽

Shuuichi FUKUDA

Keyword(s):

Fatigue Crack ◽

Fatigue Crack Growth ◽

Crack Growth ◽

Growth Path ◽

Preliminary Study ◽

Crack Growth Path

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Prediction of fatigue crack growth path in mechanical joints using a weight function approach

Fatigue & Fracture of Engineering Materials & Structures ◽

10.1046/j.1460-2695.2002.00538.x ◽

2002 ◽

Vol 25 (10) ◽

pp. 985-991 ◽

Cited By ~ 2

Author(s):

S. P. HEO ◽

W. H. YANG

Keyword(s):

Fatigue Crack ◽

Fatigue Crack Growth ◽

Weight Function ◽

Crack Growth ◽

Function Approach ◽

Growth Path ◽

Mechanical Joints ◽

Crack Growth Path

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Research on Microstructure Dependence of Near-Threshold Fatigue Crack Propagation by Combined Analyses of Fracture Surface and Fatigue Crack Growth Path

Volume 6: Materials and Fabrication, Parts A and B ◽

10.1115/pvp2009-77448 ◽

2009 ◽

Author(s):

Ming-Liang Zhu ◽

Fu-Zhen Xuan ◽

Guo-Zhen Wang ◽

Zheng-Dong Wang

Keyword(s):

Fatigue Crack ◽

Fatigue Crack Growth ◽

Crack Propagation ◽

Crack Growth ◽

Crack Advance ◽

Growth Path ◽

Austenite Grain Size ◽

Fatigue Crack Growth Resistance ◽

Crack Growth Path ◽

Near Threshold

Near-threshold fatigue crack growth behavior was investigated in a newly developed steel 25Cr2NiMo1V with different heat treatments to meet different property requirements of high-pressure (HP) and low-pressure (LP) parts in the combined steam turbine rotor. The load-shedding method was adopted in the near-threshold fatigue crack growth experiment at room temperature with a constant load ratio of 0.1. Combined analyses of crack surface and fatigue crack growth path were carried out to identify the dominant crack growth mechanisms in both HP and LP. Results show that in the threshold regime, fatigue crack growth resistance of the HP is clearly superior to that of LP and hence shows strongly dependence on the microstructure of 25Cr2NiMo1V. The distributed bainitic microstructures and larger prior austenite grain size in HP result in more tortuous crack propagation path than that in LP. Compared with ferritic blocks in HP, the tempered martensitic laths in LP do not play a dominate role in stopping the fatigue crack advance.

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