scholarly journals Strain heterogeneities at the ductile to brittle transition; a case study on ice

2017 ◽  
Author(s):  
Thomas Chauve ◽  
Maurine Montagnat ◽  
Cédric Lachaud ◽  
David Georges ◽  
Pierre Vacher
Keyword(s):  
Dynamic Recrystallization ◽  
Crack Opening ◽  
Local Strain ◽  
Image Correlation ◽  
Deformation Bands ◽  
Homologous Temperature ◽  
Brittle Transition ◽  
Polycrystalline Ice ◽  
Ductile To Brittle Transition ◽  
High Homologous Temperature

Abstract. This paper presents, for the first time, the evolution of local strain fields around intragranular cracking in polycrystalline ice, at the onset of tertiary creep. Owing to the high homologous temperature conditions and relatively low compressive stress applied, stress concentration at crack tips is relaxed by plastic mechanisms associated with dynamic recrystallization. Strain field evolution followed by Digital Image Correlation indirectly shows the redistribution of stresses during crack opening, but also driven by crack tip plasticity mechanisms and recrystallization. Such redistribution induces modifications in the local strain deformation bands, and crack closure during deformation. A strong interaction between cracking and dynamic recrystallization is therefore evidenced at the ductile to brittle transition in ice deformed at high homologous temperature.

scholarly journals Strain field evolution at the ductile-to-brittle transition: a case study on ice

Solid Earth ◽  
2017 ◽  
Vol 8 (5) ◽  
pp. 943-953 ◽  
Author(s):  
Thomas Chauve ◽  
Maurine Montagnat ◽  
Cedric Lachaud ◽  
David Georges ◽  
Pierre Vacher
Keyword(s):  
Stress Concentration ◽  
Dynamic Recrystallization ◽  
Strain Field ◽  
Crack Opening ◽  
Local Stress ◽  
Image Correlation ◽  
Brittle Transition ◽  
Field Evolution ◽  
Crack Tips ◽  
Ductile To Brittle Transition

Abstract. This paper presents, for the first time, the evolution of the local heterogeneous strain field around intra-granular cracking in polycrystalline ice, at the onset of tertiary creep. Owing to the high homologous temperature conditions and relatively low compressive stress applied, stress concentration at the crack tips is relaxed by plastic mechanisms associated with dynamic recrystallization. Strain field evolution followed by digital image correlation (DIC) directly shows the redistribution of strain during crack opening, but also the redistribution driven by crack tip plasticity mechanisms and recrystallization. Associated local changes in microstructure induce modifications of the local stress field evidenced by crack closure during deformation. At the ductile-to-brittle transition in ice, micro-cracking and dynamic recrystallization mechanisms can co-exist and interact, the later being efficient to relax stress concentration at the crack tips.

scholarly journals The nucleation of the Izmit and Düzce earthquakes: Some mechanical logic on where and how ruptures began

2021 ◽  
Author(s):  
Michel Bouchon ◽  
Hayrullah Karabulut ◽  
Mustafa Aktar ◽  
Serdar Özalaybey ◽  
Jean Schmittbuhl ◽  
...  
Keyword(s):  
Strike Slip ◽  
Seismic Events ◽  
Fault Geometry ◽  
Brittle Transition ◽  
The North ◽  
Impending Rupture ◽  
Natural Tendency ◽  
Ductile To Brittle Transition ◽  
Mechanical Logic ◽  
Rupture Speed

Summary In spite of growing evidence that many earthquakes are preceded by increased seismic activity, the nature of this activity is still poorly understood. Is it the result of a mostly random process related to the natural tendency of seismic events to cluster in time and space, in which case there is little hope to ever predict earthquakes? Or is it the sign that a physical process that will lead to the impending rupture has begun, in which case we should attempt to identify this process. With this aim we take a further look at the nucleation of two of the best recorded and documented strike-slip earthquakes to date, the 1999 Izmit and Düzce earthquakes which ruptured the North Anatolian Fault over ∼200 km. We show the existence of a remarkable mechanical logic linking together nucleation characteristics, stress loading, fault geometry and rupture speed. In both earthquakes the observations point to slow aseismic slip occurring near the ductile-to-brittle transition zone as the motor of their nucleation.

scholarly journals Probing the Statistical Validity of the Ductile-to-Brittle Transition in Metallic Nanowires Using GPU Computing

2013 ◽  
Vol 9 (12) ◽  
pp. 5558-5566 ◽  
Author(s):  
William R. French ◽  
Amulya K. Pervaje ◽  
Andrew P. Santos ◽  
Christopher R. Iacovella ◽  
Peter T. Cummings
Keyword(s):  
Gpu Computing ◽  
Metallic Nanowires ◽  
Brittle Transition ◽  
Statistical Validity ◽  
Ductile To Brittle Transition

scholarly journals Fracture and Ductile-to-Brittle Transition Characteristics of Molybdenum by Impact and Static Bend Tests

1995 ◽  
Vol 36 (4) ◽  
pp. 504-510 ◽  
Author(s):  
Yutaka Hiraoka ◽  
Hiroaki Kurishita ◽  
Minoru Narui ◽  
Hideo Kayano
Keyword(s):  
Brittle Transition ◽  
Bend Tests ◽  
Ductile To Brittle Transition

Effects of thermal treatments on the ductile to brittle transition of MANET steel

1996 ◽  
Vol 233-237 ◽  
pp. 248-252 ◽  
Author(s):  
P. Gondi ◽  
R. Montanari ◽  
A. Sili ◽  
M.E. Tata
Keyword(s):  
Thermal Treatments ◽  
Brittle Transition ◽  
Ductile To Brittle Transition
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