Notch Sensitivity and Crack Initiation Position Influence on Life Evaluation of Notched Specimens under Non-proportional Multiaxial Low Cycle Fatigue

2017 ◽  
Vol 2017 (0) ◽  
pp. OS0517
Author(s):  
Stefano BRESSAN ◽  
Takahiro MORISHITA ◽  
Takamoto ITOH
Keyword(s):  
Crack Initiation ◽  
Low Cycle Fatigue ◽  
Notch Sensitivity ◽  
Cycle Fatigue ◽  
Notched Specimens ◽  
Life Evaluation

Investigation of Fatigue Behaviour and Notch Sensitivity of Ti-6Al-4V

2011 ◽  
Vol 80-81 ◽  
pp. 7-12 ◽  
Author(s):  
Shabnam Hosseini ◽  
Mohammad Bagher Limooei
Keyword(s):  
Biomedical Application ◽  
Low Cycle Fatigue ◽  
Fatigue Behaviour ◽  
Notch Sensitivity ◽  
Cycle Fatigue ◽  
Bending Fatigue ◽  
Notched Specimens ◽  
Bending Fatigue Test ◽  
Sensitivity Data ◽  
Low Sensitivity

In this research, fatigue behaviour of Ti-6Al-4V alloy was investigated for smooth and notched specimens with stress concentration factor(Kt) 3.6 and 4.1.This investigation was conducted for various diameter bars having different ultimate strength.Rotating bending fatigue test at R= -1 was emploied for this research. Notch sensitivity data was compared with those of steels. The result indicated that the presence of notch in this alloy has a different amount of sensitivity when the notch specimens were subjected to high cycle fatigue (HCF) and low cycle fatigue(LCF) tests.The notch sensitivity of this alloy was shown generally to be much lower than steel alloys with similar ultimate strength values. Therefore,considering the low sensitivity to notch of this alloy, can be recommended for applications with the presence of notch such as biomedical application

Life Prediction for Notched Components in Nonproportional Low Cycle Fatigue: Experiment and FEM Analysis

2004 ◽  
Author(s):  
Masao Sakane ◽  
Tsuneo Itoh ◽  
Tomoshige Susaki ◽  
Yoshiyasu Kawazoe
Keyword(s):  
Crack Initiation ◽  
Linear Models ◽  
Low Cycle Fatigue ◽  
Notch Root ◽  
Fem Analysis ◽  
Local Strain ◽  
304 Stainless Steel ◽  
Cycle Fatigue ◽  
Notched Specimens ◽  
Strain Paths

This paper studies the low cycle fatigue of circumferential notched specimens of type 304 stainless steel in nonproportional loading. Strain controlled tension-torsion low cycle fatigue tests were carried out using the notched specimens under 15 strain paths. Crack initiation lives detected by a d.c. potential method were discussed in relation to the strain concentration factors and strain histories. Finite element analyses were carried out for evaluating the local strain at the notch root using elastic-perfectly plastic and bi-linear models. The maximum principal strain and nonproportional strain ranges conservatively estimated the crack initiation lives of the notched specimens.

Notch Effect in Low-Cycle Fatigue at Elevated Temperatures—Life Prediction From Crack Initiation and Propagation Considerations

1986 ◽  
Vol 108 (4) ◽  
pp. 279-284 ◽  
Author(s):  
Masao Sakane ◽  
Masateru Ohnami
Keyword(s):  
Crack Initiation ◽  
Elevated Temperatures ◽  
Low Cycle Fatigue ◽  
Strain Range ◽  
Notch Effect ◽  
Cycle Fatigue ◽  
Crack Initiation And Propagation ◽  
Total Strain Range ◽  
Notched Specimens ◽  
Initiation And Propagation

This paper describes the notch effect in low-cycle fatigue of an austenitic stainless steel SUS 304 at 873 K in air. Total strain range-controlled tests were carried out using a round unnotched and three round notched specimens. A prediction method for low-cycle fatigue lives of notched specimens was developed by predicting the crack initiation and propagation periods separately. To predict the former Neuber’s rule was applied and a nominal stress/strain criterion was developed to predict the latter. Failure lives, obtained by adding the two prediction lives, closely agree with observed failure lives.

Low-cycle fatigue-crack initiation study in Ren� 95

1975 ◽  
Vol 10 (9) ◽  
pp. 1571-1581 ◽  
Author(s):  
M. N. Menon ◽  
W. H. Reimann
Keyword(s):  
Fatigue Crack ◽  
Crack Initiation ◽  
Low Cycle Fatigue ◽  
Fatigue Crack Initiation ◽  
Cycle Fatigue

Considerations of crack initiation and crack propagation in low-cycle fatigue

1975 ◽  
Vol 9 (11) ◽  
pp. 1141-1146 ◽  
Author(s):  
P.S. Maiya
Keyword(s):  
Crack Initiation ◽  
Crack Propagation ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue

Rapid method for low cycle fatigue properties: thickness effect on the fatigue crack initiation life of welded joints

2015 ◽  
Vol 38 (12) ◽  
pp. 1492-1506 ◽  
Author(s):  
J. Raujol-Veillé ◽  
D. Thévenet ◽  
C. Doudard ◽  
S. Calloch ◽  
H. Minnebo
Keyword(s):  
Fatigue Crack ◽  
Crack Initiation ◽  
Rapid Method ◽  
Welded Joints ◽  
Low Cycle Fatigue ◽  
Fatigue Crack Initiation ◽  
Thickness Effect ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Crack Initiation Life

Fatigue Behaviour of the Novel Titanium Alloys TIMETAL® 407 and TIMETAL® 412

2021 ◽  
Author(s):  
◽  
William Davey
Keyword(s):  
Crack Initiation ◽  
Titanium Alloys ◽  
Low Cycle Fatigue ◽  
Fatigue Crack Initiation ◽  
Charpy Impact ◽  
Fatigue Behaviour ◽  
High Energy ◽  
Process Window ◽  
Cycle Fatigue ◽  
The Impact

TIMETAL®407 (Ti-407) is a medium strength (~650MPa 0.2%YS) titanium alloy, recently developed by TIMET, in conjunction with Rolls-Royce plc for use in applications requiring high energy absorption at impact. Preliminary Charpy Impact (V notch) testing showed Ti-407 to absorb nearly twice the impact energy of Ti-6-4 and exhibit more than 2.5 times the lateral expansion. Further initial testing suggested the high cycle fatigue (HCF) run out stress of Ti-407 matches that of Ti-6-4 and other high strength alpha-beta titanium alloys. Ti-407 displayed more than double the tool life than that of Ti-6-4. The reduction in tool wear supports lower forces required for faster, more efficient machining. Compared to Ti-6-4, the relatively low elevated temperature flow stress, greater malleability and wide process window should allow Ti-407 to be processed with fewer reheats, while exhibiting reduced surface cracking and giving a consistently good surface finish. Optimised Ti-407 manufacturing processes should allow parts to be formed closer to net shape giving higher yields and requiring less machining to the components finished size. This project has evaluated HCF, as well as low cycle fatigue (LCF) and dwell fatigue crack initiation mechanisms in Ti-407, to clarify the effects of alloy chemistry, microstructural morphology and scale, and crystallographic texture. A derivative of Ti-407, Ti-412 (~750MPa 0.2%YS) was also tested towards the end of the project and helped to further elucidate understanding of the fatigue characteristics of the two alloys. Of interest was the strong HCF response displayed relative to the monotonic tensile strength. As well as the investigation into the crack initiation mechanisms, an assessment of crack propagation across a range of microstructural conditions was carried out on Ti-407 material.

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