Effect of hydride precipitation on the fatigue cracking behavior in a zirconium alloy cladding tube

2019 ◽  
Vol 129 ◽  
pp. 105230 ◽  
Author(s):  
Jianghua Li ◽  
Zhiyang Wang ◽  
Yao Cheng ◽  
Yunchang Xin ◽  
Hao Wu ◽  
...  
Keyword(s):  
Zirconium Alloy ◽  
Fatigue Cracking ◽  
Cracking Behavior ◽  
Hydride Precipitation

SEM In Situ Investigation on Fatigue Cracking Behavior of X80 Pipeline Steel with Inclusions

2011 ◽  
Vol 284-286 ◽  
pp. 1096-1100 ◽  
Author(s):  
Ke Tong ◽  
Yan Ping Zeng ◽  
Xin Li Han ◽  
Yao Rong Feng ◽  
Xiao Dong He
Keyword(s):  
Crack Initiation ◽  
Pipeline Steel ◽  
Fatigue Cracking ◽  
Fatigue Loading ◽  
In Situ Observation ◽  
X80 Pipeline Steel ◽  
Cracking Behavior ◽  
The Matrix ◽  
Extension Period

The micro-mechanical behavior of inclusions in X80 pipeline steel under fatigue loading was investigated by means of SEM in situ observation. The influence of sizes and shapes of inclusion on crack initiation and propagation was analyzed. The result shows that for large-size single-particle inclusion, cracks initiate from the interior under the fatigue loading. When a certain circulation cycles are reached, cracks initiate at the matrix near the sharp corner of the inclusion. The cracks extend at the matrix during the stable extension period and unstable extension period following the crack initiation, until fracture occurred. For chain inclusion, cracks first initiate at the interface between inclusion and matrix within the chain area, and the circulation cycles needed for initiation are far less than single inclusion. Cracks steadily extend after the initiation, and then fracture after very short circulation cycles. A chain of inclusion with the shape corners is serious harmful to the fatigue properties.

Cumulative Damage Behavior of Anisotropic Al-6061-T6 as a Function of Axial-Torsional Loading Mode Sequence

1994 ◽  
Vol 116 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Hong Lin ◽  
Hamid Nayeb-Hashemi ◽  
Charles A. Berg
Keyword(s):  
Damage Accumulation ◽  
Low Cycle Fatigue ◽  
Constitutive Relations ◽  
Fatigue Cracking ◽  
Fatigue Tests ◽  
Multiaxial Fatigue ◽  
Cracking Behavior ◽  
Al 6061 ◽  
Damage Models ◽  
Loading Mode

Two types of low cycle fatigue tests were conducted along two principal orthotropic directions of an orthotropic Al-6061-T6 plate in strain control at room temperature: (1) reference fatigue tests under three loading conditions: push-pull, torsion, and combined push-pull/torsion in-phase; (2) sequential fatigue tests in which different sequences of push-pull and torsion were performed. Fatigue cracking behavior was observed during all of the fatigue tests. Shear cracking dominated the damage of the material. Anisotropic constitutive relations of the material were used in the evaluation of several multiaxial fatigue damage models. The predictive capabilities of these models were assessed based on the results of reference fatigue tests. The damage accumulation behavior of the material was found to depend on the sequence of the loading mode. For the sequence of torsion then push-pull, the damage summation was greater than unity. However, for the sequence of push-pull then torsion, the damage accumulation was near unity as predicted by the linear damage rule. A nonlinear damage accumulation rule could represent the results of the sequential fatigue tests.

Effects of temperature and strain range on fatigue cracking behavior in Hastelloy X

2008 ◽  
Vol 62 (28) ◽  
pp. 4351-4353 ◽  
Author(s):  
H.U. Hong ◽  
I.S. Kim ◽  
B.G. Choi ◽  
H.W. Jeong ◽  
C.Y. Jo
Keyword(s):  
Strain Range ◽  
Fatigue Cracking ◽  
Cracking Behavior ◽  
Hastelloy X ◽  
Effects Of Temperature

RETROFITTING METHODS AGAINST FATIGUE CRACKING IN STEEL GIRDER WEB PENETRATION

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Chihiro Sakamoto ◽  
Masahiro Sakano ◽  
Hideyuki Konishi ◽  
Takashi Fujii
Keyword(s):  
Fatigue Life ◽  
Fatigue Cracking ◽  
Highway Bridges ◽  
Lower Surface ◽  
Strength Properties ◽  
Fatigue Tests ◽  
Stress Distributions ◽  
Steel Girder ◽  
Cracking Behavior ◽  
Weld Toe

Fatigue cracking in steel girder web penetration details is so dangerous that it can break steel girders. Since a number of highway bridges have such web penetration details in Japan, it is of urgent importance to grasp these fatigue strength properties and develop effective retrofitting methods. In a previous report, we investigated the stress distributions around web penetration details, and fatigue cracking behavior, using steel girder specimens with web penetration details. In this study, we investigate effects of retrofitting methods against fatigue cracking in web penetration details through fatigue tests using large girder specimens with web penetration details in which cross beam lower flanges are connected to lower surface of a slot by welding. Principal results obtained through this study are as follows: (1) Weld toe grinding can extend fatigue life more than 5 times, (2) Two-face attachment can extend fatigue life more than 10 times, and (3) Two-face attachment with weld toe grinding can extend fatigue life more than 25 times.

Impact of Aging on the Viscoelastic Properties and Cracking Behavior of Asphalt Mixtures

2019 ◽  
Vol 2673 (6) ◽  
pp. 406-415 ◽  
Author(s):  
Runhua Zhang ◽  
Jo E. Sias ◽  
Eshan V. Dave ◽  
Reyhaneh Rahbar-Rastegar
Keyword(s):  
Viscoelastic Properties ◽  
Complex Modulus ◽  
Fatigue Cracking ◽  
Compact Tension ◽  
Asphalt Mixtures ◽  
Fatigue Properties ◽  
Cracking Behavior ◽  
Stiffness Reduction ◽  
Fracture Tests

Aging can significantly affect the viscoelastic properties and cracking behavior of asphalt mixtures, causing increase in stiffness, reduction in relaxation capability, and increase in brittleness. Eleven mixtures are evaluated using different laboratory conditioning protocols to evaluate how the properties of asphalt mixtures, including viscoelastic properties, fatigue, and fracture behavior will change over time. Comparisons between different aging levels and mixtures are conducted by using complex modulus (E*) (field cores are included), simplified viscoelastic continuum damage (S-VECD) approach, semi-circular bending (SCB), and disk shaped compact tension (DCT) fracture tests. The climatic aging index developed by the NCHRP 09-54 project is utilized in this study to calculate the appropriate field aging duration corresponding to the different laboratory aging protocols. Pavement evaluation tools FlexPAVETM and IlliTC are also used to predict and compare the fatigue and thermal cracking performance of these mixtures. The results of E* and S-VECD tests indicate that the mixtures are more prone to fatigue cracking with aging, and the two long-term conditioning protocols induce statistically similar changes in linear viscoelastic and fatigue properties. However, prediction of fatigue performance from FlexPAVE TM does not show a consistent trend once pavement structure and traffic are considered. Fracture tests and IlliTC predictions show the virgin mixtures and those with soft base binders will have better capability to resist cracking after long-term aging. In this study, the two mixtures with the largest difference between high and low temperature performance grade (PG) show the largest change in fracture and fatigue properties with aging.

Sign in / Sign up

Export Citation Format

Share Document