Modeling Grain Size Heterogeneity Effects on Mechanical Behavior of Crystalline Rocks Under Compressive Loading

2018 ◽  
pp. 177-184
Author(s):  
Jun Peng ◽  
Louis Ngai Yuen Wong ◽  
Cee Ing Teh
Keyword(s):  
Grain Size ◽  
Mechanical Behavior ◽  
Compressive Loading ◽  
Crystalline Rocks ◽  
Heterogeneity Effects ◽  
Size Heterogeneity

scholarly journals Influence of grain size heterogeneity on strength and microcracking behavior of crystalline rocks

2017 ◽  
Vol 122 (2) ◽  
pp. 1054-1073 ◽  
Author(s):  
Jun Peng ◽  
Louis Ngai Yuen Wong ◽  
Cee Ing Teh
Keyword(s):  
Grain Size ◽  
Crystalline Rocks ◽  
Size Heterogeneity

Paradox of Strength and Ductility in Metals Processed Bysevere Plastic Deformation

2002 ◽  
Vol 17 (1) ◽  
pp. 5-8 ◽  
Author(s):  
R. Z. Valiev ◽  
I. V. Alexandrov ◽  
Y. T. Zhu ◽  
T. C. Lowe
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Yield Strength ◽  
Mechanical Behavior ◽  
High Strength ◽  
High Ductility ◽  
Elongation To Failure ◽  
Failure Ductility ◽  
Strength And Ductility

It is well known that plastic deformation induced by conventional forming methodssuch as rolling, drawing or extrusion can significantly increase the strength of metalsHowever, this increase is usually accompanied by a loss of ductility. For example, Fig.1 shows that with increasing plastic deformation, the yield strength of Cu and Almonotonically increases while their elongation to failure (ductility) decreases. Thesame trend is also true for other metals and alloys. Here we report an extraordinarycombination of high strength and high ductility produced in metals subject to severeplastic deformation (SPD). We believe that this unusual mechanical behavior is causedby the unique nanostructures generated by SPD processing. The combination ofultrafine grain size and high-density dislocations appears to enable deformation by newmechanisms. This work demonstrates the possibility of tailoring the microstructures ofmetals and alloys by SPD to obtain both high strength and high ductility. Materialswith such desirable mechanical properties are very attractive for advanced structuralapplications.

Heterogeneity Effects in X-Ray Analysis*

1961 ◽  
Vol 5 ◽  
pp. 335-354 ◽  
Author(s):  
Fernand Claisse ◽  
Claude Samson
Keyword(s):  
Grain Size ◽  
Size Effect ◽  
Mathematical Treatment ◽  
Grain Size Effect ◽  
Light Elements ◽  
X Ray Diffraction ◽  
Limited Region ◽  
X Ray ◽  
Grain Sizes ◽  
Heterogeneity Effects

AbstractA fundamental quantitative treatment of the heterogeneity effects in X-ray fluorescence has been made. The theory predicts that the grain-size effect appears only in a limited region of grain sizes which depends on the wavelength of the primary radiation and the nature of the compounds in the mixture. With monochromatic radiation, the fluorescence intensity showed increase or decrease by a factor of a few units as grain size is decreased, A factor as large as 12, the theoretical value, has been observed in one particular experiment. Usually the grain-size effect can be eliminated by intensive grinding. For the light elements fine grinding is disastrous if long wavelengths are used. By an appropriate choice of the wavelength it is possible to eliminate the effect even without grinding. The mathematical treatment also predicts, but less rigorously, a grain-size effect in X-ray diffraction.The effect on the fluorescence intensities by changes in the chemical composition of the grains that contain the fluorescent element is predicted by the theory.These findings are discussed in relation to the analysis of elements when polychromatic beams are used.

Grain Size Distribution Effect on Mechanical Behavior of Nanocrystalline Materials

2004 ◽  
Vol 821 ◽  
Author(s):  
A.V. Sergueeva ◽  
N.A. Mara ◽  
A.K. Mukherjee
Keyword(s):  
Grain Size ◽  
Mechanical Behavior ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Nanocrystalline Materials ◽  
Tensile Deformation ◽  
Size Structure ◽  
Niti Alloy ◽  
Distribution Effect ◽  
The Matrix

AbstractGrain size distribution effect on the mechanical behavior of NiTi and Vitroperm alloys were investigated. Yielding at significantly lower stresses than found in equiaxed counterparts, along with well defined strain hardening was observed in these nanocrystalline materials with large grains embedded in the matrix during tensile deformation at temperatures of 0.4Tm. At higher temperature the effect of grain size distribution on yield stress was not revealed while plasticity was increased in 50% in NiTi alloy with bimodal grain size structure.

scholarly journals Influence of machining damage generated during trimming of CFRP composite on the compressive strength

2019 ◽  
Vol 54 (11) ◽  
pp. 1413-1430 ◽  
Author(s):  
N Nguyen-Dinh ◽  
C Bouvet ◽  
R Zitoune
Keyword(s):  
Surface Roughness ◽  
Mechanical Behavior ◽  
Composite Structures ◽  
Compressive Loading ◽  
Machined Surface ◽  
Reinforced Plastic ◽  
Cfrp Composite ◽  
Optical Topography ◽  
Induced Defects ◽  
Machining Damage

Machining of composite materials is a challenging task due to the heterogeneity and anisotropy of composite structures. The induced defects reduce integrity of the machined surface as well as the loading capacity of the composite structure in service. Therefore, it is necessary to quantify the damage induced during trimming and correlate the quality of the machined surface to mechanical properties. The correlation of the surface roughness criteria, widely used in literature, to the mechanical behavior raise several contradictions. For this reason, new parameters for the characterization of the machined surface are proposed and correlated to the mechanical behavior under compressive loading. In this context, carbon fiber-reinforced plastic laminates are conventionally trimmed, and the machining damage is characterized using scanning electron microscope observations, X-ray tomography, and 3D optical topography. The results reveal that crater volume and maximum depth of damage quantify the machining damage more realistic compared to the classical surface roughness criteria.

The Effect of Strain Rate and Temperature on the Mechanical Behavior of Al/Fe Interface Under Compressive Loading

2020 ◽  
Vol 51 (5) ◽  
pp. 2573-2589
Author(s):  
Zeina G. El Chlouk ◽  
Mutasem A. Shehadeh ◽  
Ramsey F. Hamade
Keyword(s):  
Strain Rate ◽  
Mechanical Behavior ◽  
Compressive Loading
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