Mixed-Mode Fatigue Crack Growth in Stainless Steels Under Biaxial Loading

1996 ◽  
Vol 118 (3) ◽  
pp. 349-355 ◽  
Author(s):  
Cai-Fu Qian ◽  
Ming-O Wang ◽  
Bao-Juan Wu ◽  
Shu-Ho Dai ◽  
J. C. M. Li
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Crack Growth ◽  
Stainless Steels ◽  
Mixed Mode ◽  
Biaxial Loading ◽  
Initial Crack ◽  
Mode I ◽  
The Relationship ◽  
Crack Paths

Mixed-Mode fatigue crack propagation tests were carried out in stainless-steel cruciform specimens in which a center initial crack oriented at 45 deg was loaded biaxially. When the loadings were in-phase, the crack was deflected with the initial crack growth angles less than 50 deg and when they were out-of-phase, it was branched with the initial crack growth angles larger than 50 deg. In all the cases, the deflected or branched cracks propagated in Mode I, namely ΔKII was almost always zero along the crack paths. The relationship between deflected or branched cracks during propagation was also analyzed.

Fatigue Crack Growth Thresholds of Deflected Mixed-Mode Cracks in PWA1484

2005 ◽  
Vol 127 (1) ◽  
pp. 2-7 ◽  
Author(s):  
K. S. Chan ◽  
J. Feiger ◽  
Y.-D. Lee ◽  
R. John ◽  
S. J. Hudak,
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Mixed Mode ◽  
Fatigue Cracks ◽  
Symmetry Plane ◽  
Crystallographic Analysis ◽  
Mode I ◽  
Test Technique ◽  
Crack Paths

The fatigue crack growth (FCG) behavior of PWA1484 single crystals was characterized in air under mixed-mode loading at 593°C as a function of crystallographic orientation using an asymmetric four-point bend test technique. Most mixed-mode fatigue cracks deflected from the symmetry plane and propagated as transprecipitate, noncrystallographic cracks, while self-similar fatigue crack growth occurred on the (111) planes in (111)/[011] and 111/[112]¯ oriented crystals. The local stress intensity factors and the crack paths of the deflected mixed-mode cracks were analyzed using the finite-element fracture mechanics code, FRANC2D/L. The results indicated that the deflected crack path was close to being normal to the maximum tensile stress direction where the Mode II component diminishes. Crystallographic analysis of the deflected crack paths revealed that the Mode I and the deflected mixed-mode cracks were usually of different crystallographic orientations and could exhibit different Mode I FCG thresholds when the crystallography of the crack paths differed substantially. These results were used to identify the driving force and conditions for cracking mode transition.

Pre-Strain Effects on Mixed-Mode Fatigue Crack Propagation Behaviour of the P355NL1 Pressure Vessels Steel

2018 ◽  
Author(s):  
João Ferreira ◽  
José A. F. O. Correia ◽  
Grzegorz Lesiuk ◽  
Sergio Blasón González ◽  
Maria Cristina R. Gonzalez ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Propagation ◽  
Crack Growth ◽  
Fatigue Crack Propagation ◽  
Mixed Mode ◽  
Pressure Vessels ◽  
Mode I ◽  
Pure Mode

Pressure vessels and piping are commonly subjected to plastic deformation during manufacturing or installation. This pre-deformation history, usually called pre-strain, may have a significant influence on the resistance against fatigue crack growth of the material. Several studies have been performed to investigate the pre-strain effects on the pure mode I fatigue crack propagation, but less on mixed-mode (I+II) fatigue crack propagation conditions. The present study aims at investigating the effect of tensile plastic pre-strain on fatigue crack growth behavior (da/dN vs. ΔK) of the P355NL1 pressure vessel steel. For that purpose, fatigue crack propagation tests were conducted on specimens with two distinct degrees of pre-strain: 0% and 6%, under mixed mode (I+II) conditions using CTS specimens. Moreover, for comparison purposes, CT specimens were tested under pure mode I conditions for pre-strains of 0% and 3%. Contrary to the majority of previous studies, that applied plastic deformation directly on the machined specimen, in this work the pre-straining operation was carried out prior to the machining of the specimens with the objective to minimize residual stress effects and distortions. Results revealed that, for the P355NL1 steel, the tensile pre-strain increased fatigue crack initiation angle and reduced fatigue crack growth rates in the Paris region for mixed mode conditions. The pre-straining procedure had a clear impact on the Paris law constants, increasing the coefficient and decreasing the exponent. In the low ΔK region, results indicate that pre-strain causes a decrease in ΔKth.

Mixed mode (I+II) fatigue crack growth in puddle iron

2017 ◽  
Vol 185 ◽  
pp. 175-192 ◽  
Author(s):  
Grzegorz Lesiuk ◽  
Paweł Kucharski ◽  
José A.F.O. Correia ◽  
A.M.P. De Jesus ◽  
C. Rebelo ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Mixed Mode ◽  
Mode I

Simulation of Fatigue Initiation and Non-Self-Similar Fatigue Crack Growth under Mixed Mode I/II Loading

2012 ◽  
Vol 224 ◽  
pp. 303-306
Author(s):  
Chen Chen Ma ◽  
Xiao Gui Wang
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Mixed Mode ◽  
Mode I ◽  
Fatigue Initiation ◽  
Self Similar ◽  
Crack Growth Model

The fatigue initiation and non-self-similar fatigue crack growth behavior of three notched compact tension and shear specimens of 16MnR steel under mixed mode I/II loading were investigated. The plane-stress finite element model with the implemented Armstrong-Frederick type cyclic plasticity model was used to calculate the elastic-plastic stress-strain responses. A recently developed dynamic crack growth model was used to simulate the effects of loading history on the successive crack growth. With the outputted numerical results, a multiaxial fatigue damage criterion based on the critical plane was used to determine the location of fatigue initiation. A formula of fatigue crack growth rate, which is based on the postulation that the fatigue initiation and crack growth have the same damage mechanism, was then used to calculate the transient crack growth rate and determine the non-self-similar crack growth path. The predicted fatigue initiation position, crack path and crack growth rate are in excellent agreement with the experimental data.

scholarly journals Mixed mode I/II/III fatigue crack growth in S355 steel

2017 ◽  
Vol 5 ◽  
pp. 896-903 ◽  
Author(s):  
D. Rozumek ◽  
Z. Marciniak ◽  
G. Lesiuk ◽  
J.A.F.O. Correia
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Mixed Mode ◽  
Mode I
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