STUDY ON THE FATIGUE DAMAGE OF A ROTOR UNDER OIL-WHIP BY CONTINUUM DAMAGE MECHANICS

2004 ◽  
Vol 40 (06) ◽  
pp. 5 ◽  
Author(s):  
Jianping Jing
Keyword(s):  
Fatigue Damage ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Oil Whip

Finite Element Modeling of Fatigue Damage Using a Continuum Damage Mechanics Approach

2005 ◽  
Vol 127 (2) ◽  
pp. 157-164 ◽  
Author(s):  
Abı´lio M. P. De Jesus ◽  
Alfredo S. Ribeiro ◽  
Anto´nio A. Fernandes
Keyword(s):  
Finite Element ◽  
Fatigue Damage ◽  
Damage Mechanics ◽  
Kinematic Hardening ◽  
Fatigue Crack Initiation ◽  
Continuum Damage Mechanics ◽  
Cyclic Plasticity ◽  
Continuum Damage ◽  
Elastoplastic Behavior ◽  
Fatigue Model

In this paper, a fatigue model formulated in the framework of the continuum damage mechanics (CDM) is presented. The model is based on an explicit definition of fatigue damage and introduces a kinematic damage differential equation formulated directly as a function of the number of cycles and the stress cycle parameters. The model is initially presented for uniaxial problems, which facilitates the identification of its constants. An extension of the fatigue model to multiaxial problems is also proposed. This model was implemented in a nonlinear finite element code in conjunction with a constitutive model for cyclic plasticity. The cyclic plasticity model considered is based on a J2-plasticity theory with nonlinear isotropic and kinematic hardenings. In order to enhance the description of the cyclic elastoplastic behavior, the superposition of several nonlinear kinematic hardening variables is suggested. Both fatigue and plasticity models are identified for the P355NL1 (TStE355) steel. Finally, the numerical model is used to predict the fatigue crack initiation for a welded nozzle-to-plate connection, made of P355NL1 steel, and results are compared with experimental fatigue data.

Fatigue and fretting fatigue life prediction of double-lap bolted joints using continuum damage mechanics-based approach

2016 ◽  
Vol 26 (1) ◽  
pp. 162-188 ◽  
Author(s):  
Ying Sun ◽  
George Z Voyiadjis ◽  
Weiping Hu ◽  
Fei Shen ◽  
Qingchun Meng
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Damage Mechanics ◽  
Failure Modes ◽  
Damage Model ◽  
Continuum Damage Mechanics ◽  
Fretting Fatigue ◽  
Bolted Joints ◽  
Continuum Damage ◽  
Bolted Joint

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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