scholarly journals On the fatigue and dwell-fatigue behavior of a low-density steel and the correlated microstructure origin of damage mechanism

2021 ◽  
Author(s):  
A. Moshiri ◽  
A. Zarei-Hanzaki ◽  
A.S. Anousheh ◽  
H.R. Abedi ◽  
Seok Su Sohn ◽  
...  
Keyword(s):  
Fatigue Behavior ◽  
Damage Mechanism ◽  
Low Density ◽  
Dwell Fatigue

Investigation on ratcheting-fatigue behavior and damage mechanism of GH4169 at 650 ℃

2019 ◽  
Vol 743 ◽  
pp. 314-321 ◽  
Author(s):  
Y.M. Liu ◽  
L. Wang ◽  
G. Chen ◽  
B.B. Li ◽  
X.H. Wang
Keyword(s):  
Fatigue Behavior ◽  
Damage Mechanism

scholarly journals Effect of Rise and Fall Time on Dwell Fatigue Behavior of a High Strength Titanium Alloy

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 914 ◽  
Author(s):  
Qingyuan Song ◽  
Yanqing Li ◽  
Lei Wang ◽  
Ruxu Huang ◽  
Chengqi Sun
Keyword(s):  
Titanium Alloy ◽  
Fatigue Life ◽  
Crack Initiation ◽  
Cross Section ◽  
Fatigue Behavior ◽  
Circular Cross Section ◽  
High Strength ◽  
Initiation Mechanism ◽  
Fall Time ◽  
Dwell Fatigue

Frequency is an important factor influencing the fatigue behavior. Regarding to the dwell fatigue, it corresponds to the effect of rise and fall time, which is also an important issue especially for the safety evaluation of structure parts under dwell fatigue loading, such as the engines of aircrafts and the pressure hulls of deep-sea submersibles. In this paper, the effect of rise and fall time (2 s, 20 s, 110 s, and 200 s) on the dwell fatigue behavior is investigated for a high strength titanium alloy Ti-6Al-2Sn-2Zr-3Mo-X with basket-weave microstructure. It is shown that the dwell fatigue life decreases with increasing the rise and fall time, which could be correlated by a linear relation in log–log scale for both the specimen with circular cross section and the specimen with square cross section. The rise and fall time has no influence on the crack initiation mechanism by the scanning electron microscope observation. The cracks initiate from the specimen surface and all the fracture surfaces present multiple crack initiation sites. Moreover, the facet characteristic is observed at some crack initiation sites for both the conventional fatigue and dwell fatigue tests. The paper also indicates that the dwell period of the peak stress reduces the fatigue life and the dwell fatigue life seems to be longer for the specimen with circular cross section than that of the specimen with square cross section.

Thermomechanical Damage Development in SiC(SCS6)/Ti-6-4 Metal Matrix Composite

1992 ◽  
Author(s):  
S. Aksoy
Keyword(s):  
Fatigue Behavior ◽  
High Stress ◽  
Damage Mechanism ◽  
Material Behavior ◽  
Effect Of Temperature ◽  
Damage Development ◽  
Element Analysis ◽  
Mechanical Cycling ◽  
Single Temperature ◽  
Thermomechanical Damage

A series of experiments were conducted to investigate the thermomechanical fatigue behavior of SiC(SCS-6)/Ti-6-4 composite. Three types of tests were conducted. In the first, specimens were subjected to load-controlled mechanical cycling under isothermal conditions. The other two types of test involved simultaneous cycling of load and temperature: in-phase and out-of-phase cycles. The effect of temperature cyclic ranges of 250°C to 528°C were evaluated for the out-of-phase (low temperature-high stress) conditions. A single temperature range of 250°C was employed for the in-phase (high temperature-high stress) condition. Fatigue-life diagrams were developed to evaluate the fatigue performance of the composite based on certain damage mechanism maps. In addition, micromechanical stresses in the fiber and matrix were computed using a generalized plane strain finite element analysis. The intention of this analytical effort was to provide the understanding of the fundamental mechanisms governing material behavior for guiding the development of life prediction methodology.

Fully Reversed Electric Fatigue Behavior of a Piezoelectric Composite Actuator

2008 ◽  
Author(s):  
Sung-Choong Woo ◽  
Nam Seo Goo
Keyword(s):  
Fatigue Damage ◽  
Fatigue Behavior ◽  
Damage Mechanism ◽  
Ceramic Layer ◽  
Piezoelectric Composite ◽  
Transgranular Fracture ◽  
Intergranular Cracking ◽  
Composite Actuator ◽  
Electric Fatigue ◽  
Pzt Ceramic

The aim of this study is to investigate fully reversed electric fatigue behavior of a piezoelectric composite actuator (PCA). For that purpose, fatigue tests with different loading conditions have been conducted and the performance degradation has been monitored. During a preset number of loading cycles, non-destructive acoustic emission (AE) tests were used for monitoring the damage evolution in real time. The displacement-cycle curves were obtained in fully reversed cyclic bending loading. The microstructures and fracture surfaces of PCA were examined to reveal their fatigue damage mechanism. The results indicated that the AE technique was applicable to fatigue damage assessment in the piezoelectric composite actuator. It was shown that the initial damage mechanism of PCAs under fully reversed electric cyclic loading originated from the transgranular fracture in the PZT ceramic layer; with increasing cycles, local intergranular cracking initiated and the either developed onto the surface of the PZT ceramic layer or propagated into the internal layer, which were some different depending on the drive frequencies and the lay-up sequence of the PCA.

Fatigue behavior and damage mechanism of carbon/carbon composites: a review

2013 ◽  
Vol 9 (2) ◽  
pp. 284-288 ◽  
Author(s):  
Xi Yang ◽  
Hejun Li ◽  
Shouyang Zhang ◽  
Kuahai Yu ◽  
Zhi Wang
Keyword(s):  
Fatigue Behavior ◽  
Damage Mechanism ◽  
Carbon Composites

524 Effect of Density on Contact Fatigue Behavior and Damage Mechanism of Sintered Alloys

2001 ◽  
Vol 2001.9 (0) ◽  
pp. 409-410
Author(s):  
Makoto HORIKOSHI ◽  
Yukio MIYASHITA ◽  
Rajapa Gnanamoorthy ◽  
Jin-Quan XU ◽  
Yoshiharu MUTOH ◽  
...  
Keyword(s):  
Fatigue Behavior ◽  
Contact Fatigue ◽  
Damage Mechanism ◽  
Sintered Alloys

Continuous damage-based Voronoi finite element analysis of contact fatigue of a wind turbine gear

2019 ◽  
Vol 233 (10) ◽  
pp. 1483-1495
Author(s):  
Peitang Wei ◽  
Huaiju Liu ◽  
Caichao Zhu ◽  
Haifeng He
Keyword(s):  
Finite Element ◽  
Wind Turbine ◽  
Mechanical Response ◽  
Fatigue Behavior ◽  
Maximum Shear Stress ◽  
Contact Fatigue ◽  
Damage Mechanism ◽  
Mechanical Transmission ◽  
Element Analysis ◽  
Gear Contact

Contact fatigue failures of gears, especially those used in heavy duty conditions such as wind turbine gears, become important issues in mechanical transmission industry. In the present work, a continuous damage mechanism and Voronoi-based finite element model is developed to investigate the contact fatigue of a wind turbine gear. Plane strain assumption is adopted to simplify the gear contact model. Voronoi tessellations are utilized to represent the microstructure topology of the gear material, and continuous damage mechanism is implemented to reflect the material degradation within critical substrate area. With the developed framework, the contact pressure distribution, intergranular mechanical response and the progressive fatigue damage at the grain boundaries during repeated gear meshing are evaluated and discussed in detail. The depths of the maximum shear stress reversal and the crack initiation agree well with previously reported findings. The influence of microstructure on the gear contact fatigue behavior is also investigated.

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