Discussion of fracture paper #41 - Are dislocation good or bad guys? It depends!
Around Shifting from macroscopic to microscopic plasticity helps us understand mechanisms that can help us develop high-strength metallic materials. Things that prevent dislocation dynamics or generation, such as other dislocations and grain boundaries in polycrystalline materials, lead to higher strength.t...
Discussion of fracture paper #40 - Icicle or carrot, which one has isotropic fracture properties?
Around 20 years ago, I gave a fracture mechanics lecture and talked about crack initiation that happens in the plane with the largest tensile stress. True, at least if the material has isotropic properties. The students already knew where an isotropic material would give the largest stress at bending and torsion. I planned to make a desktop experiment with an icicle and a carrot...
Discussion of fracture paper #39 - Dynamic Fracture on a Molecular Level
Dynamic fracture is a never-ending story. In 1951, EH Yoffe obtained an analytical solution for a crack of constant length travelling at constant speed along a plane. She used a Galilean transformation to get a solution for arbitrary speeds. The situation seems strange with a crack tip where the material breaks and a lagging tip where the material heals. However, there are applications...
Discussion of fracture paper #38 - Fracture of the thinnest of sheets - Graphene
The Nobel laureate Andre Geim made graphene by playing with pencil leads and Scotch tape and coauthored a paper on how to get the Nobel prize the fun way. Before that, he co-authored with his hamster, Ter Tisha, a paper on diamagnetic levitation and demonstrated it on a frog. He was honoured with the Ig Nobel prize for the paper and later became the only person so far...
Discussion of fracture paper #37 - A Novel Approach Improving Mode I+III Cohesive Zone Modellingl
The advantage of simplicity is that mechanics and physics can be understood and predicted just by using pen and paper. In the end, numerics may have to be used but then you should already have a pretty good idea of what happens. The other way around, starting with numerics and a limited toolbox of models will seldom lead to anything new...
Discussion of fracture paper #36 - The Double-K Fracture Model
The fracture of concrete and other semi-brittle materials offers some simplifications that simplify the analytical analysis. The simple check that reveals if something broken requires an elastic or an elastic-plastic fracture mechanical analysis by just trying to fit the pieces together sometimes fails. The suggestion is that if they do not fit together, we have an elastic-plastic fracture and...
Discussion of fracture paper #35 - What is Finite Fracture Mechanics?
The subject of this blog is a well-written and technically detailed study of thermal crack initiation where an adhesive joint between two dissimilar materials meets a free surface. The method that is used goes under the group designation finite fracture mechanics. The paper is "Predicting thermally induced edge-crack initiation using finite fracture mechanics" by S. Dölling, S. Bremm, A. Kohlstetter, J. Felger, and W. Becker, in Engineering Fracture Mechanics 252 (2021)
Discussion of fracture paper #34 - On the Physics of Hydrogen Embrittlement
Hydrogen embrittlement causes problems that probably will become apparent to an increasing extent as hydrogen is taken into general use for energy storage and as a fuel for heating and electricity production. According to Wikipedia, the phenomenon has been known since at least 1875. The subject of this blog
Discussion of fracture paper #33 - The Interaction Integral
This blog concerns an interesting review of the interaction integral methodology. It deserves to be read by everyone dealing with analyses of cracks. If one's focus is on mathematical analysis or numerics is irrelevant. The review is for all of us. The review paper is ”Interaction integral method for computation of crack parameters K–T – A review", by Hongjun Yu and Meinhard Kuna, Engineering Fracture Mechanics, Volume 249, 15 May 2021, 107722, p. 1-34.
Discussion of fracture paper #32 - Fatigue and Machine-learning
The paper, "A machine-learning fatigue life prediction approach of additively manufactured metals" by Hongyixi Bao, Shengchuan Wu, Zhengkai Wu, Guozheng Kang, Xin Peng, Philip J. Withers in Engineering Fracture Mechanics 242 (2021) 107508, p. 1-10., adopts a very interesting view of the correlation between fault geometry and fatigue properties. A simplified statistical description of irregular faults in large numbers is used.
Discussion of fracture paper #31 - Toughness of a Rigid Foam
A most readworthy paper, "Static and dynamic mode I fracture toughness of rigid PUR foams under room and cryogenic temperatures" by E. Linul, L. Marşavina, C. Vălean, R. Bănică, Engineering Fracture Mechanics, 225, 15 February 2020, 106274, 1-10. is selected for this ESIS blog. It has received a lot of attention and was for an extended period...
Discussion of fracture paper #30 - Weight Functions, Cracks and Corners
Weight functions are practical tools in linear elastic systems where several discrete or continuously distributed sources cause something, deformation, stress, or related stuff. In linear fracture mechanics, as also in the object of this blog, weight functions are used to calculate stress intensity factors...
Discussion of fracture paper #29 - Fast Crack Growth in Fibre Reinforced Composites
The outstanding and brilliantly written paper, "Modeling of Dynamic Mode I Crack Growth in Glass Fiber-reinforced Polymer Composites" by Liu, Y, van der Meer, FP, Sluys, LJ and Ke, L, Engineering Fracture Mechanics, 243, 2021, applies a numerical model to study the dynamics of a crack...
Discussion of fracture paper #28 - Rate effects and dynamic toughness of concrete
The paper "Estimating static/dynamic strength of notched unreinforced concrete under mixed-mode I/II loading" by N. Alanazi and L. Susmel in Engineering Fracture Mechanics 240 (2020) 107329, pp. 1-18, is a readworthy and very interesting paper. Extensive fracture mechanical testing of concrete is throughly described in...
Discussion of fracture paper #27 - Phase-field modelling of cracks and interfaces
Landau and Ginzburg formulated a theory that includes the free energy of phases, with the purpose to derive coupled PDEs describing the dynamics of phase transformations. Their model with focus on the phase transition process itself also found many other applications, not the least because many exact solutions can be obtained. During the last few decades, with...
Discussion of fracture paper #26 - Cracks and anisotropic materials
All materials are anisotropic, that's a fact. Like the fact that all materials have a nonlinear response. This we can't deny. Still enormous progress has been made by assuming both isotropy and linear elasticity. The success, as we all know, is due to the fact that many construction materials are very close to being both isotropic and linear...
Discussion of fracture paper #25 - The role of the fracture process region
The subject of this blog is a fracture mechanical study of soft polymers. It is well written and technically detailed which makes the reading a good investment. The paper: Experimental and numerical assessment of the work of fracture in injection-moulded low-density polyethylene, M. Kroon et al.
Discussion of fracture paper #24 - The sound of crack growth
Carbon fibre reinforced polymers combines desired features from different worlds. The fibres are stiff and hard, while the polymers are the opposite, weak, soft and with irrelevant fracture toughness. Irrelevant considering the small in-plane deformation that the fibres can handle before they break.
Discussion of fracture paper #23 - Paris' exponent m<2 and behaviour of short cracks
I came across a very interesting paper in Engineering Fracture Mechanics about a year ago. It gives some new results of stochastic aspects of fatigue. The paper is: ”On the distribution and scatter of fatigue lives obtained
Discussion of fracture paper #22 - Open access puts scientists in control of their own results
The last ESIS blog about how surprisingly few scientists are willing/able to share their experimental data, received an unexpectedly large interest. Directly after the publication another iMechanica blogger took the same theme but he put the focus on results produced at numerical analyses that are presented with insufficient
Discussion of fracture paper #21 - Only 6% of experimentalists want to disclose raw-data
Long term availability of raw experimental data in experimental fracture mechanics, by Patrick Diehl, Ilyass Tabiai, Felix W. Baumann, Daniel Therriault and Martin Levesque, in Engineering Fracture Mechanics, 197 (2018) 21–26.
Discussion of fracture paper #20 - Add stronger singluarities to improve numerical accuracy
Evaluation of stress intensity factors under multiaxial and compressive conditions using low order displacement or stress field fitting, R. Andersson et al., in Engineering Fracture Mechanics, 189 (2018) 204–220.
Discussion of fracture paper #19 - Fracture mechanical properties of graphene
Growth speed of single edge pre-crack in graphene sheet under tension, Jun Hua et al., Engineering Fracture Mechanics 182 (2017) 337–355.
Discussion of fracture paper #18 - A crack tip energy release rate caused by T-stress
Zi-Cheng Jiang, Guo-Jin Tang, Xian-Fang Li, Effect of initial T-stress on stress intensity factor for a crack in a thin pre-stressed layer, Engineering Fracture Mechanics, pp. 19-27.
Discussion of fracture paper #17 - What is the second most important quantity at fracture?
Fracture assessment based on unified constraint parameter for pressurized pipes with circumferential surface cracks, M.Y. Mu, G.Z. Wang, F.Z. Xuan, S.T. Tu, Engineering Fracture Mechanics 175 (2017), 201–218
Discussion of fracture paper #16 - What is wrong with pure mode I and II? A lot it seems
An improved definition for mode I and mode II crack problems" by M.R. Ayatollahi, M. Zakeri in Engineering Fracture Mechanics 175 (2017) 235–246.
Discussion of fracture paper #15 - Design for crack arrest
Brittle crack propagation/arrest behaviour in steel plate – Part I: Model formulation” by Kazuki Shibanuma, Fuminori Yanagimoto, Tetsuya Namegawa, Katsuyuki Suzuki, Shuji Aihara in Engineering Fracture Mechanics, 162 (2016) 324-340.
Discussion of fracture paper #14 - How to understand the J-integral when multiple cracks are growing at different rates
Fracture resistance enhancement of layered structures by multiple cracks, S. Goutianos and B.F. Sørensen, Engineering Fracture Mechanics, 151 (2016) 92-108.
Discussion of fracture paper #13 - Cohesive properties at ductile tearing
Cohesive zone modeling and calibration for mode I tearing of large ductile plates, P.B. Woelke, M.D. Shields, J.W. Hutchinson, Engineering Fracture Mechanics, Vol 147 (2015) pp. 293-305.
Discussion of fracture paper #12 - Crack paths and fracture process region autonomy
Method for calculating G, G_I, and G_II to simulate crack growth in 2D, multiple-material structures, E.K. Oneida, M.C.H. van der Meulen, A.R. Ingraffea, Engineering Fracture Mechanics, Vol 140 (2015) pp. 106–126.
Discussion of fracture paper #11 - Fracture processes and phase field modelling
A phase field method to simulate crack nucleation and propagation in strongly heterogeneous materials from direct imaging of their microstructure, T.T. Nguyen, J. Yvonnet, Q.-Z. Zhu, M. Bornert, C. Chateau, Engineering Fracture Mechanics, Vol 139 (2015) pp. 18–39.
Discussion of fracture paper #10 - Searching for the length scale of stress corrosion
Further study on crack growth model of buried pipelines exposed to concentrated carbonate-bicarbonate solution, B.T. Lu, Engineering Fracture Mechanics vol. 131 (2014) pp. 296-314.
Discussion of fracture paper #9 - Crack tip modelling
Effect of a single soft interlayer on the crack driving force, M. Sistaninia and O. Kolednik, Engineering Fracture Mechanics, Vol. 130, 2014, pp. 21–41.
Discussion of fracture paper #8 - Elastic follow-up
P.M. James: Re-derivation of plasticity interaction for combined loading under significant levels of elastic follow-up. Engineering Fracture Mechanics, Vol. 126, 2014, pp. 12–26.
Discussion of fracture paper #7 - Configurational force approach
K. Özenç, M. Kaliske, G. Lin, G. Bhashyam: Evaluation of energy contributions in elasto-plastic fracture: A review of the configurational force approach, Engineering Fracture Mechanics, 2014, Vol. 115, pp. 137-153.
Discussion of fracture paper #6 - Stress intensity factor for steep yield distribution
T. Yasuoka, Y. Mizutani, A. Todoroki: Applicable limit of the stress intensity factor for steep yield strength distribution, Engineering Fracture Mechanics, 2013, Vol. 110, pp. 1-11.
Discussion of fracture paper #5 - Yield ciriterion or failure criterion
Henrik Danielsson and Per Johan Gustafsson: A three dimensional plasticity model for perpendicular to grain cohesive fracture in wood, Engineering Fracture Mechanics Vol. 98 2013, pp.137–152.
Discussion of fracture paper #4 - Is paper ductile?
P. Mäkelä and S. Östlund: Cohesive crack modelling of thin sheet material exhibiting anisotropy, plasticity and large-scale damage evolution. Engineering Fracture Mechanics,Vol. 79, 2012 pp. 50-60.
Discussion of fracture paper #3 - Length scales in fracture
H. Krull and H. Yuan: Suggestions to the cohesive traction–separation law from atomistic simulations. Engineering Fracture Mechanics, Vol. 78, 2011, pp. 525-533.
Discussion of fracture paper #2 - The role of the T-stress
J.C. Sobotka, R.H. Dodds: Steady crack growth in a thin, ductile plate under small-scale yielding conditions: Three-dimensional modelling., Engineering Fracture Mechanics, Vol. 78, 2011, pp. 343-363; J.C. Sobotka, R.H. Dodds: T-stress effects on steady crack growth in a thin, ductile plate under small-scale yielding conditions: Three-dimensional modelling., Engineering Fracture Mechanics, Vol. 78, 2011, pp. 1182-1200.
Discussion of fracture paper #1 - A contol volume model
Ehsan Barati, Younes Alizadeh, Jamshid Aghazadeh Mohandesi: J-integral evaluation of austenitic-martensitic functionally graded steel in plates weakened by U-notches, Engineering Fracture Mechanics, Vol. 77, Issue 16, 2010, pp. 3341-3358.
A blog for discussing fracture papers
The aim of ESIS is not only to develop and extend knowledge in all aspects of structural integrity, but also to disseminate this knowledge world-wide by means of scientific publications and to educate young engineers and scientists. For these purposes, three Elsevier journals - Engineering Fracture Mechanics , Engineering Failure Analysis and >> Read more
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