scholarly journals Multiaxial High Cycle Fretting Fatigue

2019 ◽  
Vol 300 ◽  
pp. 02002
Author(s):  
José Alexander Araújo ◽  
Gabriel Magalhães Juvenal Almeida ◽  
Fábio Comes Castro ◽  
Raphael Araújo Cardoso
Keyword(s):  
Fretting Fatigue ◽  
Accurate Estimate ◽  
Multiaxial Fatigue ◽  
Fretting Wear ◽  
Critical Plane ◽  
Life Estimation ◽  
Wide Range ◽  
Tools And Techniques ◽  
Critical Direction ◽  
High Cycle Fretting Fatigue

The aim of this work is to show that multiaxial fatigue can be successfully adpted to model fretting problems. For instance, the paper presents (i) the critical direction method, as an alternative to the critical plane concept, to model the crack initiation path under fretting conditions and (ii) studies on size effects considering the influence of incorporating fretting wear on the life estimation. A wide range of new data generated by a two actuators fretting fatigue rig considering Al 7050-T7451 and of Ti-6Al-4V aeronautical alloys is produced to validate these analyses. It is shown that, the development of appropriate tools and techniques to incorporate the particularities of the fretting phenomenon into the multiaxial fatigue problem allow an accurate estimate of the fretting fatigue resistance/life in the medium high cycle regime. Such tools and techniques can be extended to the design of other mechanical components under similar stress enviroments.

Effects of process variables on fretting fatigue crack initiation in Ti-6A1-4V

2002 ◽  
Vol 37 (6) ◽  
pp. 535-547 ◽  
Author(s):  
S A Namjoshi ◽  
S Mall ◽  
V K Jain ◽  
O Jin
Keyword(s):  
Fatigue Crack ◽  
Crack Initiation ◽  
Coefficient Of Friction ◽  
Fatigue Crack Initiation ◽  
Orientation Angle ◽  
Fretting Fatigue ◽  
Multiaxial Fatigue ◽  
Process Variables ◽  
Critical Plane ◽  
The Coefficient Of Friction

A fretting fatigue crack initiation mechanism (number of cycles, location and orientation angle) using critical plane based parameters has been addressed by several researchers. There are several process variables that can affect these parameters and thereby the prediction of fretting fatigue crack initiation behaviour. Effects of two such parameters, viz. process volume and the coefficient of friction, were investigated in this work. Fretting fatigue experiments with a titanium alloy were conducted with different contact pad geometries. Finite element analysis (FEA) was used to obtain a stress state in specimens for the experimental conditions used during fretting fatigue tests. Analysis was carried out for two values of the coefficient of friction, thereby providing a framework for calculation of several critical plane based multiaxial fatigue parameters for different process volumes. A program was developed to compute these multiaxial fatigue parameters from the FEA data for different values of process variables. It was observed that parameters for cylindrical pad geometries with no singularity-type behaviour were inversely proportional to the size of process volume and directly proportional to the coefficient of friction. There was no change in the predicted orientation of the primary crack for this geometry, due to variations in these process variables. Parameters for flat-pad geometries with behaviour approaching that of a singularity were also inversely proportional to the size of process volume, but the coefficient of friction had a minimal effect on their values. Predicted orientation of the primary crack for these geometries changed slightly when the process volume increased from that of a grain size of the tested material to a larger size, and then did not change with the increase of process volume size. Overall, the effect of these process variables on the critical plane based parameters was similar in all five contact geometries used in this study, when the scatter in fatigue data is kept in mind. Finally, the modified shear stress range parameter satisfactorily predicted the crack initiation location, orientation angle and number of cycles to fretting fatigue crack initiation independent of the contact geometry for a given process volume size and coefficient of friction.

Cracking under fretting fatigue: Damage prediction under multiaxial fatigue

2002 ◽  
Vol 37 (6) ◽  
pp. 519-533 ◽  
Author(s):  
M-C Dubourg ◽  
Y Berthier ◽  
L Vincent
Keyword(s):  
Crack Initiation ◽  
Prediction Models ◽  
Crack Nucleation ◽  
Fretting Fatigue ◽  
Multiaxial Fatigue ◽  
Stage I ◽  
Fretting Wear ◽  
Stage Ii ◽  
Contact Conditions ◽  
Damage Prediction

Fretting is one of the plagues of modern industry. It occurs whenever a junction between components is subjected to cyclic sliding, with small relative displacements at the interface of the contacting surfaces. Further cyclic bulk stresses may be superimposed on to one or both components. The investigation of fretting wear and fretting fatigue started in the early 1970s. It is responsible for premature fatigue failures and often limits the life of a component. Crack initiation and growth under fretting contact conditions have been investigated. The fretting map concepts allow the first degradation responses of the material—no degradation, cracking and wear—to be related to a fretting regime with its corresponding local contact conditions during fretting tests. The fretting fatigue prediction models have been developed and compared to experiments conducted either on metallic or photoelastic materials. A special emphasis has been directed towards crack nucleation and early growth during stage I, the stage I-stage II transition and stage II crack growth (crack initiation sites, orientation, growth path, formation of a branch, growth mechanism). The analysis of the different stages that comprise the crack lifetime has been carried out in order to understand the effects of diverse parameters that are thought to influence the fretting damage.

Finite Element Analysis of Fretting Stresses

1997 ◽  
Vol 119 (4) ◽  
pp. 797-801 ◽  
Author(s):  
P. A. McVeigh ◽  
T. N. Farris
Keyword(s):  
Finite Element ◽  
Tensile Stress ◽  
Element Model ◽  
Fretting Fatigue ◽  
Maximum Tensile Stress ◽  
Multiaxial Fatigue ◽  
Fretting Wear ◽  
Symmetric Distribution ◽  
Element Analysis ◽  
Riveted Joints

Clamped contacts subjected to vibratory loading undergo cyclic relative tangential motion or micro-slip near the edges of contact. This cyclic micro-slip, known as fretting, leads to removal of material through a mechanism known as fretting wear and formation and growth of cracks through a mechanism known as fretting fatigue. In aircraft, fretting fatigue occurs at the rivet/hole interface leading to multisite damage which is a potential failure mechanism for aging aircraft. A finite element model of a current fretting fatigue experiment aimed at characterizing fretting in riveted joints is detailed. A non-symmetric bulk tension is applied to the specimen in addition to the loads transferred from the fretting pad. The model is verified through comparison to the Mindlin solution for a reduced loading configuration, in which the bulk tension is not applied. Results from the model with the bulk tension show that the distribution of micro-slip in the contact is not symmetric and that for some loads reversed micro-slip occurs. Finite element results are given for the effects that four different sets of loading parameters have on the maximum tensile stress induced by fretting at the trailing edge of contact. It can be shown using multiaxial fatigue theory that this stress controls fretting fatigue crack formation. This maximum tensile stress is compared to that of the Mindlin solution for a symmetric distribution of micro-slip. This stress is also compared to that of a variation based on the Mindlin solution for the cases with a non-symmetric distribution of micro-slip. It is concluded that the solution based on the Mindlin variation and the full finite element solution lead to similar predictions of the maximum tensile stress, even when the shear traction solutions differ significantly.

Fatigue Life Evaluation of Press-Fitted Specimens by Using Multiaxial Fatigue Theory at Contact Edge

2005 ◽  
Vol 297-300 ◽  
pp. 108-114 ◽  
Author(s):  
Dong Hyung Lee ◽  
Byeong Choon Goo ◽  
Chan Woo Lee ◽  
Jae Boong Choi ◽  
Young Jin Kim
Keyword(s):  
Fatigue Life ◽  
Crack Initiation ◽  
Fatigue Crack Initiation ◽  
Fretting Fatigue ◽  
Cyclic Stress ◽  
Multiaxial Fatigue ◽  
Critical Plane ◽  
Bending Load ◽  
The Press ◽  
Number Of Cycles

In the shrink or press-fitted shafts such as railway axles, fretting can occur by cyclic stress and micro-slippage due to local movement between shaft and boss. When the fretting occurs in the press-fitted shaft, the fatigue strength remarkably decreases compared with that of without fretting. In this paper fretting fatigue life of press-fitted specimens was evaluated using multiaxial fatigue criteria based on critical plane approaches. An elastic-plastic analysis of contact stresses in a press-fitted shaft in contact with a boss was conducted by finite element method and micro-slip due to the bending load was analyzed. The number of cycles of fretting fatigue and the crack orientation were compared with the experimental results obtained by rotating bending tests. It is found that the crack initiation of fretting fatigue between shaft and boss occurs at the contact edge and the normal stress on the critical plane of contact interface was an important parameter for fretting fatigue crack initiation. Furthermore, the results indicated that a critical plane parameter could predict the orientation of crack initiation in the press-fitted shaft.

Multiaxial Fatigue of 16MnR Steel

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
Zengliang Gao ◽  
Tianwen Zhao ◽  
Xiaogui Wang ◽  
Yanyao Jiang
Keyword(s):  
Pure Shear ◽  
Ambient Air ◽  
Shear Loading ◽  
Multiaxial Fatigue ◽  
Experimental Results ◽  
Pressure Vessel Steel ◽  
Critical Plane ◽  
Cracking Behavior ◽  
Vessel Steel ◽  
Axial Torsion

Uniaxial, torsion, and axial-torsion fatigue experiments were conducted on a pressure vessel steel, 16MnR, in ambient air. The uniaxial experiments were conducted using solid cylindrical specimens. Axial-torsion experiments employed thin-walled tubular specimens subjected to proportional and nonproportional loading. The true fracture stress and strain were obtained by testing solid shafts under monotonic torsion. Experimental results reveal that the material under investigation does not display significant nonproportional hardening. The material was found to display shear cracking under pure shear loading but tensile cracking under tension-compression loading. Two critical plane multiaxial fatigue criteria, namely, the Fatemi–Socie criterion and the Jiang criterion, were evaluated based on the experimental results. The Fatemi–Socie criterion combines the maximum shear strain amplitude with a consideration of the normal stress on the critical plane. The Jiang criterion makes use of the plastic strain energy on a material plane as the major contributor to the fatigue damage. Both criteria were found to correlate well with the experiments in terms of fatigue life. The predicted cracking directions by the criteria were less satisfactory when comparing with the experimentally observed cracking behavior under different loading conditions.

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