A Continuum Damage Mechanics (CDM) Modeling Approach for Prediction of Fatigue Failure of Metallic Bolted Joints

Fatigue and fretting fatigue are the main failure mode in bolted joints when subjected to cyclic load. Based on continuum damage mechanics, an elastic–plastic fatigue damage model and a fretting fatigue damage model are combined to evaluate the fatigue property of bolted joints to cover the two different failure modes arisen at two possible critical sites. The predicted fatigue lives agree well with the experimental results available in the literature. The beneficial effects of clamping force on fatigue life improvement of the bolted joint are revealed: part of the load is transmitted by friction force in the contact interface, and the stress amplitude at the critical position is decreased due to the reduction in the force transmitted by the bolt. The negative effect of fretting damage on the bolted joint is also captured in the simulation.

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A Continuum Damage Mechanics Model for Multiaxial Low Cycle Fatigue Failure

Journal of the Mechanical Behavior of Materials ◽

10.1515/jmbm.2001.12.1.1 ◽

2001 ◽

Vol 12 (1) ◽

pp. 1-20

Author(s):

Alexander Zolochevsky, ◽

Takamoto Itoh, ◽

Yoichi Obataya,

Keyword(s):

Fatigue Failure ◽

Damage Mechanics ◽

Low Cycle Fatigue ◽

Continuum Damage Mechanics ◽

Continuum Damage ◽

Cycle Fatigue ◽

Mechanics Model

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Numerical estimation of fretting fatigue life of bolted joints using continuum damage mechanics and SEAM Tool

Advances in Structural Engineering ◽

10.1177/1369433220911155 ◽

2020 ◽

Vol 23 (11) ◽

pp. 2486-2499

Author(s):

Xinhao Lin ◽

Yazhou Xu ◽

Hui Zhang ◽

Qianqian Ren ◽

Junqi Yu

Keyword(s):

Fatigue Life ◽

Damage Mechanics ◽

Continuum Damage Mechanics ◽

Fretting Fatigue ◽

Cyclic Stress ◽

Initial Crack ◽

Bolted Joints ◽

Propagation Path ◽

Continuum Damage ◽

Tightening Torque

For fretting fatigue, micro-slipping often causes initial micro-cracks in the contact surfaces, which gradually propagate and eventually result in fracture failure. However, it is difficult to directly observe and measure the crack initiation and propagation processes of single-lap bolted joints due to the obstacle of testing technique. Therefore, this article presents an elastic analysis–based method, in which the total fretting fatigue lifetime is divided into initiation life predicted by continuum damage mechanics and propagation life calculated by SEAM Tool in combination with Paris’s law. Since the initiation life model implicitly reflects the result of damage process, one can directly calculate the initiation life based on the elastic stress analysis. The predicted fretting fatigue life, initial crack location, and propagation path are in reasonable agreement with the fretting fatigue test and scanning electron microscope observation results. In addition, it is found that among the main factors affecting fretting fatigue of steel single-lap bolted joints, the initial life is affected by cyclic stress, friction coefficient, and tightening torque, and the propagation path is mainly influenced by tightening torque.

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