Mixed-Mode Fatigue Crack Propagation of Penny-Shaped Cracks

1993 ◽  
Vol 115 (4) ◽  
pp. 365-372 ◽  
Author(s):  
W. R. Chen ◽  
L. M. Keer
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Mixed Mode ◽  
Shear Loading ◽  
Small Scale ◽  
Mode I ◽  
Dugdale Model ◽  
Penny Shaped Crack ◽  
Shaped Crack

A three-dimensional penny-shaped crack under combined tensile and shear loadings is analyzed. The assumptions of Dugdale are applied to estimate the effects of plasticity around the edge of the crack. The solution for mode I tensile loading is well established within the context of the Dugdale assumptions, and for the case of shear loading, approximate results are derived for the yield ring width and crack sliding displacements, with the assumptions similar in form to the mode I case. By superposing the results of the tensile and shear loading, the solutions for a penny-shaped Dugdale crack under mixed mode static loading and modified for the analysis of fatigue crack growth. Based on the mixed mode Dugdale model and the accumulated plastic displacement criterion for crack growth, a fatigue crack growth equation with four-power effective stress intensity factor dependence is developed for a penny-shaped crack under conditions of mixed mode loading and small-scale yielding.

Fatigue Crack Growth in Mixed Mode Loading

1991 ◽  
Vol 113 (2) ◽  
pp. 222-227 ◽  
Author(s):  
Wei-Ren Chen ◽  
L. M. Keer
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Mixed Mode ◽  
Fourth Power ◽  
Small Scale ◽  
Growth Equation ◽  
J Integral ◽  
Mixed Mode Loading ◽  
Dugdale Model

In this paper, a direct approach based on the mixed mode Dugdale model, the accumulated plastic displacement criterion for crack propagation and the cyclic J-integral concept is used to develop equations to predict the mixed mode fatigue crack growth. A fourth-power stress intensity factor crack growth equation and a second-power cyclic J-integral equation are developed under conditions of mixed mode loading and small-scale yielding. By comparing the present analysis with the experimental results, the proposed fatigue crack growth rate equations lead to results that appear to yield reasonable magnitudes for various loading conditions.

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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