The life evaluation by linear cumulative damage rule for cold dwell fatigue of Ti‐6Al‐4V alloy

2021 ◽  
Author(s):  
Yutaro Ota ◽  
Keiji Kubushiro ◽  
Yasuhiro Yamazaki
Keyword(s):  
Cumulative Damage ◽  
Life Evaluation ◽  
Dwell Fatigue ◽  
Damage Rule

Cumulative damage rule under sliding wear of White metal

2003 ◽  
Vol 2003.40 (0) ◽  
pp. 315-316
Author(s):  
Yukari Tachi ◽  
Kiyoshi Tamura ◽  
Sotomi Ishihara ◽  
Takahito Goshima
Keyword(s):  
Sliding Wear ◽  
Cumulative Damage ◽  
White Metal ◽  
Damage Rule

Application of Fracture Mechanics to Determine the Remaining Lifetime of the Old Steel Bridges Decks

2015 ◽  
Vol 1111 ◽  
pp. 110-115
Author(s):  
Silvia Mihaela Hernea ◽  
Dorel Boldus ◽  
Anamaria Feier
Keyword(s):  
Fracture Mechanics ◽  
Crack Growth ◽  
Calculation Method ◽  
Bridge Deck ◽  
Steel Bridges ◽  
Cumulative Damage ◽  
Experimental Program ◽  
Steel Bridge ◽  
Classical Calculation ◽  
Damage Rule

This paper presents a procedure based on fracture mechanics to predict the evolution of cracks detected in a part of steel bridge deck, still in operation, and establishing thus remaining lifetime below a certain range of application from future traffic. It is also described an experimental program conducted on samples from available material, to determine the material factors “C” and “m” involved in Paris formula and their use in a calculation procedure for simulating crack growth detected. Finally is presented a comparison with results obtained from a classical calculation method, the cumulative damage rule of Palmergren-Miner.

A new cumulative damage rule for multilevel cyclic loading with mean stresses

1996 ◽  
Vol 75 (2) ◽  
pp. R29-R35
Author(s):  
Yu Gui-Lan ◽  
Wang Yue-Sheng ◽  
Gai Bing-Zheng
Keyword(s):  
Cyclic Loading ◽  
Cumulative Damage ◽  
Mean Stresses ◽  
Damage Rule

Corrosion mechanism and fatigue behavior of 2A70-T6 aluminum alloy under alternating corrosion and fatigue

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lei Fu ◽  
Hui Li ◽  
Li Lin ◽  
Qingyuan Wang ◽  
Qi Fan ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Corrosion Fatigue ◽  
Intergranular Corrosion ◽  
Fatigue Behavior ◽  
Cumulative Damage ◽  
Corrosion Mechanism ◽  
Corrosive Environment ◽  
Content Type ◽  
Damage Rule

Purpose Most supersonic aircraft were manufactured using 2A70 aluminum alloy. The purpose of this paper is to study the corrosion mechanism and fatigue behavior of an aircraft in a semi-industrial atmospheric corrosive environment, alternating effects of corrosion and fatigue were used to simulate the aircraft’s ground parking corrosion and air flight fatigue. Design/methodology/approach For this purpose, the aluminum alloy samples were subjected to pre-corrosion and alternating corrosion-fatigue experiments. The failure mechanisms of corrosion and corrosion fatigue were analyzed using microscopic characterization methods of electrochemical testing, X-ray diffraction and scanning electron microscopy. Miner’s linear cumulative damage rule was used to predict the fatigue life of aluminum alloy and to obtain its safe fatigue life. Findings The results showed that the corrosion damage caused by the corrosive environment was gradually connected by pitting pits to form denudation pits along grain boundaries. The deep excavation of chloride ions and the presence of intergranular copper-rich phases result in severe intergranular corrosion morphology. During cyclic loading, alternating hardening and softening occurred. The stress concentration caused by surface pitting pits and denudation pits initiated fatigue cracks at intergranular corrosion products. At the same time, the initiation of multiple fatigue crack sources was caused by the corrosion environment and the morphology of the transient fracture zone was also changed, but the crack propagation rate was not basically affected. The polarization curve and impedance analysis results showed that the corrosion rate increases first, decreases and then increases. Fatigue failure behavior was directly related to micro characteristics such as corrosion pits and microcracks. Originality/value In this research, alternating effects of corrosion and fatigue were used to simulate the aircraft’s ground parking corrosion and air flight fatigue. To study the corrosion mechanism and fatigue behavior of an aircraft in a semi-industrial atmospheric corrosive environment, the Miner’s linear cumulative damage rule was used to predict the fatigue life of aluminum alloy and to obtain its safe fatigue life.

Calculation Methods for Equivalent Fatigue Stress Amplitude Based on Corten-Dolan Accumulative Damage Rule

2010 ◽  
Vol 156-157 ◽  
pp. 1271-1274 ◽  
Author(s):  
Hong Bing Zhu
Keyword(s):  
Stress Amplitude ◽  
Equivalent Stress ◽  
Engineering Application ◽  
Fatigue Properties ◽  
Rc Beams ◽  
Test Results ◽  
Life Evaluation ◽  
Fatigue Life Evaluation ◽  
Damage Rule ◽  
Fatigue Experiment

Structures often enduring random amplitude load or multilevel amplitude load. However, the test researches on fatigue often using equivalent amplitude load. It is very important for fatigue research that how to accurately evaluate structure’s fatigue properties of random amplitude load or multilevel amplitude load when only using equivalent amplitude load fatigue test results. According to damaging degree equivalent principle of multilevel amplitude load or random amplitude load, deduced equivalent stress amplitude calculation formula using linearity Miner accumulative damage rule and Corten-Dolan accumulative damage rule. Introduced the formula’s using method on fatigue detail or fatigue life evaluation. Utilizing the S-N curve and S-N equation from RC beams fatigue experiment, verified the formula aiming at 3 RC beams’ random amplitude fatigue experiment results, and it is indicated that the formula’s results had quite high precision and approached the experimentation result though it is partial security. The formula operated convenience and it had higher precision compared to similar formula, so the formula suit for engineering application.

Investigation Into Cumulative Damage Rules to Predict Fretting Fatigue Life of Ti-6Al-4V Under Two-Level Block Loading Condition1

2003 ◽  
Vol 125 (3) ◽  
pp. 315-323 ◽  
Author(s):  
O. Jin ◽  
H. Lee ◽  
S. Mall
Keyword(s):  
Stress Amplitude ◽  
Fatigue Behavior ◽  
Fretting Fatigue ◽  
Fatigue Tests ◽  
Cumulative Damage ◽  
Order Effects ◽  
Block Loading ◽  
Crack Growth Rates ◽  
Damage Rule ◽  
Repeated Block

The effects of variable amplitude loading on fretting fatigue behavior of titanium alloy, Ti-6Al-4V were examined. Fretting fatigue tests were carried out under constant stress amplitude and three different two-level block loading conditions: high-low (Hi-Lo), low-high (Lo-Hi), and repeated block of high and low stress amplitudes. The damage fractions and fretting fatigue lives were estimated by linear and non-linear cumulative damage rules. Damage curve analysis (DCA) and double linear damage rule (DLDR) were capable to account for the loading order effects in Hi-Lo and Lo-Hi loadings. In addition, the predictions by DCA and DLDR were better than that by linear damage rule (LDR). Besides its simplicity of implementation, LDR was also capable of estimating failure lives reasonably well. Repeated two-level block loading resulted in shorter lives and lower fretting fatigue limit compared to those under constant amplitude loading. The degree of reduction in fretting fatigue lives and fatigue strength depended on the ratio of cycles at lower stress amplitude to that at higher stress amplitude. Fracture surface of specimens subjected to Hi-Lo and repeated block loading showed the clear evidence of change in stress amplitude of applied load. Especially, the repeated two-level block loading resulted in characteristic markers which reflected change in crack growth rates corresponding to different stress amplitudes.

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