scholarly journals A Study of Fatigue Crack Growth Laws in Small and Large Cracks Based on COD. (Rotating Bending Fatigue Tests of Annealed 0.45%C Steel).

1994 ◽  
Vol 60 (572) ◽  
pp. 942-945
Author(s):  
Hironobu Nisitani ◽  
Yasuji Oda ◽  
Reizo Murakami
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Tests ◽  
Bending Fatigue ◽  
Rotating Bending Fatigue ◽  
Growth Laws ◽  
Rotating Bending

On the Fatigue Crack Growth Behavior of a Nitrided and Shot Peened Steel

2007 ◽  
Vol 345-346 ◽  
pp. 375-378 ◽  
Author(s):  
Mario Guagliano ◽  
Laura Vergani
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Residual Stresses ◽  
Crack Growth ◽  
Fatigue Tests ◽  
Crack Growth Behavior ◽  
Initiation Point ◽  
Growth Properties ◽  
Micro Hole ◽  
Rotating Bending Fatigue

In this paper the fatigue crack growth properties of a nitrided shot-peened steel is dealt with: different peening intensities were considered and the resulting residual stresses measured by means of an X-ray diffractometer. Rotating bending fatigue tests were executed on specimens with a blind micro-hole, acting as a pre-existent crack. The results allowed determining the threshold of propagation of the nitrided and of nitrided and shot peened material. It was also possible to relate the crack initiation point with the applied and the residual stresses.

Fatigue/Creep Interactions in Ni3Al-Base Alloys

1988 ◽  
Vol 133 ◽  
Author(s):  
G. M. Camus ◽  
D. J. Duquette ◽  
N. S. Stoloff
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Tests ◽  
Frequency Effect ◽  
Propagation Mode ◽  
Crack Blunting ◽  
Fatigue Crack Growth Test

ABSTRACTStress-controlled fatigue tests and fatigue crack growth rate tests respectively have been carried out on two Ni3Al Cr/Zr alloys, IC 218 at 600°C and 800°C, and IC 221 at 800°C, in vacuum, at various test frequencies. Decreasing the test frequency and/or increasing the temperature leads to a decrease in the number of cycles to failure, and a gradual disappearance of a fatigue fracture zone. In fatigue crack propagation tests, the crack growth rate only decreases at the lowest frequency and remains constant in the major part of the frequency range investigated. The fatigue propagation mode in all cases is intergranular. These trends are shown in both cases to be related to a true creep component but, under fatigue crack growth test conditions, crack blunting intervenes gradually as the frequency is decreased, leading therefore to a less severe frequency effect.

scholarly journals Continuous Estimation of the Crack Growth Rate during Rotating‒Bending Fatigue Testing

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 275 ◽  
Author(s):  
Gabriela Martinez-Cazares ◽  
Rafael Mercado-Solis ◽  
Yaneth Bedolla-Gil ◽  
Diego Lozano
Keyword(s):  
Growth Rate ◽  
Crack Growth Rate ◽  
Crack Growth ◽  
Fatigue Testing ◽  
Crack Nucleation ◽  
Bending Fatigue ◽  
Initial Load ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Continuous Estimation

A method for estimating the crack growth rate in steel during rotating‒bending fatigue testing is presented. Constant deflection tests were conducted in which the initial load remained constant prior to crack nucleation, when it decreased as the crack grew. In the proposed approach, steel samples were sharp-notched to produce a characteristic circular fracture upon loading and the final fracture area was correlated with a ratio of the load prior to fracture and the initial load. In this method, the deflection imposed is a function of a material’s elastic modulus rather than its yield strength and the correlation obtained to estimate the average crack length as a function of the instantaneous load is independent of the applied stress or steel grade.

Near-Threshold Fatigue Crack Growth at 63Sn37Pb Solder Joints

2002 ◽  
Vol 124 (4) ◽  
pp. 385-390
Author(s):  
Ki-Ju Kang ◽  
Seon-Ho Choi ◽  
Tae-Sung Bae
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Tests ◽  
Lap Joint ◽  
Growth Data ◽  
Micro Structure ◽  
Crack Behavior ◽  
Temperature Aging ◽  
Near Threshold

Fatigue tests were performed using single lap-joint specimens to obtain near-threshold fatigue crack growth data of solder joint under mode-II load. Attention was focused on the effect of high temperature aging and microstructures separately from the intermetallics. As a result, it was shown that the long cast time yielded the intermetallics and microstructures of the solder invariable regardless of aging condition. The granular micro-structure of the air-cooled specimens was shown to be inferior to the laminated micro-structure of the furnace-cooled specimens. Also, transition of fatigue crack behavior with ΔJ and the procedure of fatigue crack propagation from the pre-crack tip were discussed.

Fatigue Behaviour of DLC Coated Al 7075-T6 Alloy in an Aggressive Mixture

2014 ◽  
Vol 627 ◽  
pp. 81-84 ◽  
Author(s):  
Sergio Baragetti ◽  
Riccardo Gerosa ◽  
Francesco Villa
Keyword(s):  
High Performance ◽  
Contact Fatigue ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Structural Elements ◽  
Pvd Coatings ◽  
Bending Fatigue ◽  
Al 7075 ◽  
Rotating Bending Fatigue ◽  
Rotating Bending

7075-T6 aluminium alloy is commonly adopted in high performance structures and components. Its fatigue behaviour is however dramatically worsened by exposure to aggressive environments. The deposition of PVD coatings, which are commonly adopted to increase the surface properties of structural elements in terms of hardness, contact fatigue and wear resistance, could be beneficial also for the fatigue behaviour of a 7075-T6 substrate in an aggressive environment. In the present work, Diamond Like Carbon (DLC) PVD coated 7075-T6 specimens immersed in methanol have been analysed, by means of step-loading rotating bending fatigue tests (R = -1) at 2·105 cycles. Coated specimens were tested in laboratory air for comparison, and uncoated polished samples were studied in both the environments to obtain reference values. SEM micrographs of the fracture surfaces were taken to investigate the effects of the corrosive environment on the failure mechanism.

Effect of KIII on Fatigue Crack Growth Behavior

2010 ◽  
Author(s):  
Masanori Kikuchi ◽  
Yoshitaka Wada ◽  
Chikako Ohdama
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Tests ◽  
Crack Growth Behavior ◽  
Crack Growth Simulation ◽  
Slant Surface ◽  
Cracked Specimens

Mixed mode fatigue tests are conducted using surface cracked specimen. Slant surface cracked specimens are made where crack angle is 15°, 30°, 45° and 60°. It is shown that factory roof is made at deepest point of surface crack due to ΔKIII, and crack growth rate decreases by the factory roof. Fatigue crack growth is simulated using S-version FEM (Finite Element Method) using crack growth criteria. It is shown that conventional crack growth criteria are not available to predict fatigue crack growth with factory roof. In this study, modified criterion for the prediction of crack growth rate is proposed. By using this criterion, fatigue crack growth simulation is conducted, and results are compared with those of experiments and discussed.

scholarly journals Influence of Strain Ratio on Bending Fatigue Life and Fatigue Crack Growth in TiNi Shape-Memory Alloy Thin Wires

2006 ◽  
Vol 47 (3) ◽  
pp. 759-765 ◽  
Author(s):  
Ryosuke Matsui ◽  
Yoshiyasu Makino ◽  
Hisaaki Tobushi ◽  
Yuji Furuichi ◽  
Fusahito Yoshida
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Crack Growth ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Crack Growth ◽  
Strain Ratio ◽  
Bending Fatigue ◽  
Thin Wires
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