Maximum shear stress-controlled uniaxial tensile deformation and fracture mechanisms and constitutive relations of Sn–Pb eutectic alloy at cryogenic temperatures

2021 ◽  
pp. 141523
Author(s):  
Xiaoliang Ji ◽  
Qi An ◽  
Yiping Xia ◽  
Rong An ◽  
Rui Zheng ◽  
...  
Keyword(s):  
Shear Stress ◽  
Eutectic Alloy ◽  
Tensile Deformation ◽  
Constitutive Relations ◽  
Maximum Shear Stress ◽  
Uniaxial Tensile ◽  
Fracture Mechanisms ◽  
Cryogenic Temperatures ◽  
Deformation And Fracture

Atomistic Study on Nano Stress-Strain Curves of α-Fe

1997 ◽  
Vol 492 ◽  
Author(s):  
Shenyang Hu ◽  
Matthias Ludwig ◽  
Liam Farrissey ◽  
Siegfried Schmauder
Keyword(s):  
Boundary Conditions ◽  
Tensile Deformation ◽  
Tensile Axis ◽  
Plane Boundary ◽  
Uniaxial Tensile ◽  
Stress Strain ◽  
Fracture Characteristics ◽  
Deformation And Fracture ◽  
Dislocation Movement ◽  
Atomistic Study

ABSTRACTThe atomistic processes and stress-strain-curves during uniaxial tensile deformation of a single α-Fe nanocrystal have been studied with the molecular static method. Periodic boundary conditions are imposed along one direction perpendicular to the tensile axis to model plane strain conditions. The effects of the model sizes in plane, boundary conditions and crystal orientations on the stress-strain curves are systematically analyzed. Various deformation evidences such as dislocation movement, dislocation piling up and twinning are clearly observed. The deformation and fracture characteristics of a-Fe and their dependencies on the boundary conditions are investigated.

Discussions on Fracture Factors of Brittle Materials under the Shear-Compression Condition

2011 ◽  
Vol 250-253 ◽  
pp. 90-94
Author(s):  
Zhi Hui Li ◽  
Jun Ping Shi ◽  
An Min Tang
Keyword(s):  
Shear Stress ◽  
Stress State ◽  
Uniaxial Compression ◽  
Frictional Force ◽  
Shear Fracture ◽  
Maximum Shear Stress ◽  
Brittle Materials ◽  
Fracture Mechanisms ◽  
Initiation Point ◽  
Fracture Angle

Based on fundamental ideas in tribology and basic concept of stress state in solid mechanics, the existence of frictional force on shear plane is discussed under uniaxial compression of brittle materials. On account of macroscopic fracture forms and mesoscopic fracture mechanisms, the key factors influencing shear fracture angle are analyzed. The results show that, when brittle materials are compressed and shear fracture occurs, shear fracture surface at the crack initiation point is consistent with the maximum shear stress. But the reason of shear fracture angle examined in experiment greater than 45º lies in that, the existence of frictional force between endface of specimen and pressure head of testing machine, and additional tensile stress produced in the materials when harder crystalline grain wedge in softer medium have changed original uniaxial compression stress state and the direction of maximum shear stress on next fracture path.

scholarly journals Tensile deformation and fracture mechanisms of Cu/Nb nanolaminates studied by in situ TEM mechanical tests

2018 ◽  
Vol 25 ◽  
pp. 60-65 ◽  
Author(s):  
Z. Liu ◽  
M.A. Monclús ◽  
L.W. Yang ◽  
M. Castillo-Rodríguez ◽  
J.M. Molina-Aldareguía ◽  
...  
Keyword(s):  
Tensile Deformation ◽  
Mechanical Tests ◽  
Fracture Mechanisms ◽  
In Situ Tem ◽  
Deformation And Fracture

scholarly journals Uniaxial Tensile Deformation And Fracture Process of Structures Forming By Unsaturated Intercalation of Amine Molecule Into C–S–H Gel

2021 ◽  
Author(s):  
Dawei sun ◽  
Yan Zheng ◽  
Jianhua Yan ◽  
Yali Wang ◽  
Jianfeng Wang ◽  
...  
Keyword(s):  
Fracture Process ◽  
Tensile Deformation ◽  
Mean Square Displacement ◽  
Local Stress ◽  
Dynamics Simulation ◽  
Elastic Behavior ◽  
Uniaxial Tensile ◽  
Deformation And Fracture ◽  
Amine Molecule ◽  
Interlayer Region

Abstract The application of cement based materials in engineering requires the understanding of their characteristics and subsequent deformation and fracture process of C-S-H gel in service. In this work, three types of amine molecules including TEPA, PAM and TEA were intercalated unsaturatedly into C–S–H gel successfully. Systematical analysis was performed on the structures and properties on both C–S–H gel and corresponding amine molecules / C–S–H gel. It was found that unsaturated intercalation of amine molecules into C–S–H gel plays a key role in the geometry and therein density of nanocomposites. Subsequently, radial distribution function (RDF), time correlated function (TCF) and mean square displacement (MSD) were applied to characterize the structure and dynamic information of the as-generated nanocomposites, demonstrating the occurance of interaction between amine molecules with Ca–Si layer and acceleration of water diffusion by unsaturated intercalation of amine molecules into the interlayer region in C–S–H gel. Finally, deformation and fracture process of C–S–H gel and amine molecules / C–S–H gel under uniaxial tensile loads were displayed by molecular dynamics simulation. It was indicated that Young’s modulus of nanocomposites demonstrates a strain softening nature, indicating a visco-elastic behavior. The breakage of Ca–O bonds and hydrogen bonds dominates the fracture of C–S–H gel. Weak interaction for TEPA / C–S–H gel or TEA / C–S–H gel leads to a decreased tensile strength. Local stress concentration in other interlayer region governs the deformation and fracture process in spite of the formation of strong interaction between double bonded polar oxygen atoms in PAM molecules and Ca atoms in C–S–H gel.

scholarly journals Flow of a new class of non-Newtonian fluids in tubes of non-circular cross-sections

2019 ◽  
Vol 377 (2144) ◽  
pp. 20180069 ◽  
Author(s):  
Juan P. Gomez-Constante ◽  
Kumbakonam R. Rajagopal
Keyword(s):  
Shear Stress ◽  
Velocity Field ◽  
Cross Section ◽  
Cross Sections ◽  
Applied Mathematics ◽  
Constitutive Relations ◽  
Maximum Shear Stress ◽  
Circular Cross Section ◽  
Secondary Flows ◽  
Shear Stresses

Fluids described by constitutive relations wherein the symmetric part of the velocity gradient is a function of the stress can be used to describe the flows of colloids and suspensions. In this paper, we consider the flow of a fluid obeying such a constitutive relation in a tube of elliptic and other non-circular cross-sections with the view towards determining the velocity field and the stresses that are generated at the boundary of the tube. As tubes are rarely perfectly circular, it is worthwhile to study the structure of the velocity field and the stresses in tubes of non-circular cross-section. After first proving that purely axial flows are possible, that is, there are no secondary flows as in the case of many viscoelastic fluids, we determine the velocity profile and the shear stresses at the boundaries. We find that the maximum shear stress is attained at the co-vertex of the ellipse. In general tubes of non-circular cross-section, the maximum shear stress occurs at the point on the boundary that is closest to the centroid of the cross-section. This article is part of the theme issue ‘Rivlin's legacy in continuum mechanics and applied mathematics’.

scholarly journals Ionic Liquid-Nanostructured Poly(Methyl Methacrylate)

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1376 ◽  
Author(s):  
Clarice Fedosse Zornio ◽  
Sébastien Livi ◽  
Jannick Duchet-Rumeau ◽  
Jean-François Gerard
Keyword(s):  
Methyl Methacrylate ◽  
Chemical Nature ◽  
Uniaxial Tensile ◽  
Fracture Mechanisms ◽  
Large Strains ◽  
Counter Anion ◽  
Poly Methyl Methacrylate ◽  
Deformation And Fracture ◽  
Uniaxial Tensile Stress ◽  
Pmma Blends

Here, ionic liquids (ILs) based on imidazolium and ammonium cations were used as modifying agents for poly(methyl methacrylate) (PMMA) by extrusion. The effects of the chemical nature of the cation and/or counter anion on the resulting properties of IL-modified PMMA blends were analyzed. It was found that the use of low amounts of ILs (2 wt.%) improved the thermal stability. A plasticizing effect of ILs is evidenced by a decrease in glass transition temperature Tg of the modified PMMA, allowing to get large strains at break (i.e., up to 280% or 400%) compared to neat PMMA. The deformation and fracture mechanisms of PMMA under uniaxial tensile stress (i.e., crazing) reveal that the presence of IL delayed the strain during the initiation step of crazing.

The Role of Defects on Tensile Deformation and Fracture Mechanisms of AM AlSi10Mg Alloy at Room Temperature and 250℃

2021 ◽  
pp. 108215
Author(s):  
Jianguang Bao ◽  
Zhengkai Wu ◽  
Shengchuan Wu ◽  
Dianyin Hu ◽  
Wei Sun ◽  
...  
Keyword(s):  
Room Temperature ◽  
Tensile Deformation ◽  
Fracture Mechanisms ◽  
Deformation And Fracture
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