A new energy-based effective strain theory for mechanical properties of multiphase composites

2019 ◽  
Vol 76 ◽  
pp. 279-289 ◽  
Author(s):  
Wei Liu ◽  
Lichun Bian
Keyword(s):  
Mechanical Properties ◽  
Effective Strain ◽  
Strain Theory ◽  
Multiphase Composites ◽  
New Energy

Mechanical Properties of HPC and Numerical Simulation of Mine Shaft under 3D Load

2015 ◽  
Vol 777 ◽  
pp. 48-51
Author(s):  
Hui Cao ◽  
Lin Lin Jiang
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
High Strength Concrete ◽  
Effective Strain ◽  
Earth Pressure ◽  
High Strength ◽  
Wall Structure ◽  
Concrete Wall ◽  
Mine Shaft ◽  
Strength Concrete

The mechanical properties of high-strength concrete was studied in the laboratory, and obtained a high strength concrete uniaxial compressive strength changes with curing period, found that low temperature curing C100 Poisson's ratio of concrete is 0.24, and elastic modulus reached about 52.5GPa. The test results are applied to the numerical calculation, established a separate type reinforced concrete wall, and the multiaxial loading the stress state is simulated, the research shows that it is applied to C100 reinforced concrete shaft lining under its own gravity and the surrounding soil earth pressure, the maximum effective stress are respectively 25MPa , and effective strain is 4E-4mm, structure of shaft wall failure caused by shear wall structure. Under the three state of compression, the strength of concrete is improved.

scholarly journals Correlation of Strain Path, Texture, Twinning, and Mechanical Properties in Twinning-Induced Plasticity Steel during Wire Drawing

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2250 ◽  
Author(s):  
Joong-Ki Hwang
Keyword(s):  
Mechanical Properties ◽  
Strain Path ◽  
Electron Backscatter Diffraction ◽  
Steel Wire ◽  
Effective Strain ◽  
Metal Flow ◽  
Wire Drawing ◽  
Surface Areas ◽  
The Wire ◽  
Backscatter Diffraction

The effect of changing the strain path on texture development, twin kinetics, and mechanical properties in twinning-induced plasticity steel was investigated to understand twinning behavior in more detail. Among the various plastic deformation processes, the wire drawing process was selected to achieve the aims of the study. Specimens of cold-drawn TWIP steel wire under the same effective strain but with different crystallographic textures were successfully fabricated using the effect of the wire drawing direction. Electron backscatter diffraction results showed that the drawn wires using both unidirectional (UD) and reverse-directional (RD) wire drawing processes were characterized as duplex fiber textures of major <111> and minor <100>. It was found that the RD wire had a higher fraction of <111> component at both the center and surface areas compared to the UD wire, because the metal flow of the RD wire was beneficial for the development of a <111> orientation. The pronounced <111> crystallographic orientation of the RD wire activated the twinning rate and geometrically necessary dislocation density, leading to an increase in strength but a decrease in ductility. The strain path is as important as the amount of strain for strengthening the materials, especially those that are deformed by twinning.

FINITE STRAIN MEASUREMENT USING IMAGE ANALYSIS UNDER REVERSE SHEAR AFTER FORWARD SHEAR

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Yasuyuki Kato
Keyword(s):  
Image Analysis ◽  
Effective Strain ◽  
Local Deformation ◽  
Gauge Length ◽  
Strain Theory ◽  
Strain Component ◽  
Deformation Path ◽  
Strain Behavior ◽  
Natural Strain ◽  
Shearing Strain

The purpose of this research is to investigate the progress of local deformation under finite deformation by using image analysis based on the Natural Strain theory. Since Natural Strain used in the image analysis can satisfy the addition law of strain on an identical line element and can remove the rigid body rotation from shearing strain component, it is an effective strain for representing stress and strain behavior under large deformation. Therefore, in this research, these features of Natural Strain theory will be incorporated into the method of image analysis. In the present study, using the test pieces made of high purity tough pitch copper, the local deformation occurring under large simple shear is investigated by comparing the strains in each element from the upper position to the middle position with the average strain in the gauge length. In order to investigate the progress of local deformation caused by differences of strain hardening in the material, the experiments are conducted under different deformation histories which are given by applying reverse shear after applying forward shear with different sizes. Consequently, it is revealed that if the value of plastic strain obtained by integrating over the whole deformation path is almost the same, the progress of local deformation is approximately the same even if the deformation path is different.

Overall Mechanical Properties of Particulate Porous Composites Following Two-Step Homogenization Scheme

2012 ◽  
Vol 232 ◽  
pp. 45-50 ◽  
Author(s):  
Salma Barboura ◽  
Salah Ramtani
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Iterative Process ◽  
Current Approach ◽  
Elastic Media ◽  
Effective Moduli ◽  
Multiphase Composites ◽  
Self Consistent ◽  
Homogenization Scheme ◽  
Porous Composites

The present work tries to make an attempt to improve previous work which offers a simple but effective way to construct satisfied predicating model. Indeed, recent work due to Peng et al. [13] and dealing with a two-step homogenization scheme is revisited here by introducing an iterative process which allows us to take into account differently the porosity of the elastic media. Several homogenization schemes (dilute, Mori-Tanaka, self-consistent ...) are presented and compared with experimental data. One can say that the current approach provides reasonably accurate predictions for the effective moduli of multiphase composites without using the n parameter as proposed by Peng et al. [13]

Microstructural and Mechanical Properties Enhancement in Ultrafine Grained Ni-Cr Alloy

2012 ◽  
Vol 1372 ◽  
Author(s):  
Kuk Hyun Song ◽  
Hye Jin Lee ◽  
Han Sol Kim ◽  
Won Yong Kim
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Effective Strain ◽  
Initial Material ◽  
Grain Boundary Character ◽  
Ultrafine Grained ◽  
Processed Material ◽  
Average Grain Size ◽  
Ebsd Technique ◽  
Conventional Rolling

ABSTRACTThe present study was carried out to evaluate the microstructures and mechanical properties of severely deformed Ni-30Cr alloy. Cross-roll rolling (CRR) as severe plastic deformation (SPD) process was introduced and Ni-30Cr alloy sheets were cold rolled to a 90% thickness reduction and subsequently annealed at 700 °C for 30 min so as to obtain the recrystallized microstructure. For the analysis of grain boundary character distributions (GBCDs), electron back-scattered diffraction (EBSD) technique was introduced. CRR on Ni-30Cr alloy was effective to enhance the grain refinement through heat treatment; consequently, average grain size was significantly reduced from 33 μm in initial material to 0.6 μm in CRR processed material. This grain refinement directly affected the mechanical properties improvement, in which yield and tensile strengths were significantly increased than those of initial material. In this study, we systematically discussed the grain refinement, accompanying with increase in mechanical properties, in terms of the effective strain imposed by CRR, comparing with conventional rolling (CR).

Numerical study of the effect of geometric parameters on compressive mechanical properties of metallic lattice cylinders

2021 ◽  
pp. 095440622110590
Author(s):  
Amir Mahmoud Zanganeh ◽  
Sina Ghaemi Khiavi ◽  
Bagher Mohammad Sadeghi ◽  
Mehdi Divandari
Keyword(s):  
Mechanical Properties ◽  
Strain Distribution ◽  
Lattice Structure ◽  
Numerical Study ◽  
Effective Strain ◽  
Constant Strain Rate ◽  
Maximum Energy ◽  
Strut Thickness ◽  
Simulation Results ◽  
Abaqus Software

In the current research, the numerical simulations were done on 15 cylindrical lattice specimens under compressive stress at a constant strain rate using Abaqus software. The lattice cylinders have different strut thicknesses of 3, 4, and 5 mm, and with the fillets in the radiuses of 0.3, 0.6, 0.9, and 1.2 mm, respectively. The mechanical properties of the AlSi11Cu2 (Fe) aluminum alloy were used. The Mises stress distribution was evaluated to determine the effect of fillet radius on the lattice structure for the strut thickness of 3 mm. Also, the effective strain distribution of the lattice structure was investigated after different stages of deformation. After comparing the simulation results, it was shown that by applying fillets with a radius of 0.3 mm in lattice cylinders, the maximum energy absorption and maximum force can be achieved at the ultimate tensile strength (UTS) point. Also, the optimal strain can be obtained at the UTS point.

Analytical and experimental investigation of deformation in constrained groove pressing process

2018 ◽  
Vol 233 (11) ◽  
pp. 3751-3759 ◽  
Author(s):  
Farshad Nazari ◽  
Mohammad Honarpisheh
Keyword(s):  
Mechanical Properties ◽  
Deformation Behavior ◽  
Effective Strain ◽  
Surface Hardness ◽  
Deformation Method ◽  
Pressing Process ◽  
Respective Contribution ◽  
Analytical Relations ◽  
High Ultimate Strength ◽  
Deformation Procedure

Constrained groove pressing process is a severe plastic deformation method, which can improve the properties of a metal sheet. The purpose of this research is to investigate the effect of deformation behavior and effective strain on the constrained groove pressed sheet properties. For this aim, deformation procedure and effective strain were investigated based on analytical relations and deformation geometry. Formation in the constrained groove pressing process was divided into the bending, stretching, and pressing sections, and the respective contribution of each in the formation procedure was evaluated. Then, the effect of main sections on the formation force, mechanical properties, and microstructure of constrained groove pressed sheets was determined by an experimental study. According to the analytical results, about 41.4% of the formation procedure occurs in the pressing section, creating 70% more effective strain than stretching section. Thus, the pressing section has a significant effect on the properties of constrained groove pressed sheets. The pressing section, due to more effective strain than the stretching section, creates 36% more yield strength, 14.6% more surface hardness, 37.6% more homogeneity and 22.6% smaller grain size. But, compared to the stretching section, the pressing section reduces elongation about 42.8%. So, to produce sheets with high ultimate strength and good formability, using the constrained groove pressing process in the stretching section is more effective.

Effects of Strain Rate in Cold-Rolled Pure Copper Produced by Different Rolling Processes

2011 ◽  
Vol 695 ◽  
pp. 307-311
Author(s):  
Kuk Hyun Song ◽  
Han Sol Kim ◽  
Won Yong Kim
Keyword(s):  
Mechanical Properties ◽  
Effective Strain ◽  
Pure Copper ◽  
Refined Grains ◽  
Grain Boundary Character ◽  
Processed Material ◽  
Cold Rolled ◽  
Ebsd Technique ◽  
Conventional Rolling ◽  
Electron Back Scattered Diffraction

To evaluate the microstructures and mechanical properties in cross-roll rolled pure copper, comparing with conventionally rolled materials, this work was carried out. Pure copper (99.99 mass%) sheets with thickness of 5 mm were cold rolled to 90% thickness reduction by cross-roll rolling (CRR) and subsequently annealed at 400 °C for 30 min. Also, to analyze the grain boundary character distributions (GBCDs), electron back-scattered diffraction (EBSD) technique was employed. As a result, the cold rolled and annealed materials consisted of significantly refined grains than that of the initial material (100 mm). Especially, the CRR processed material showed more refined grain size (6.5 mm) in average than that (9.8 mm) of conventional rolling (CR). These grain refinements directly affected an increase in mechanical properties. Therefore, the microstructural and mechanical properties development observed in both processes was systematically discussed in terms of the effective strain originated by the plastic deformation.

Enhancement of Grain Refinement and Formability of Cross Roll Rolled Ni-10Cr Alloy

2013 ◽  
Vol 761 ◽  
pp. 95-99
Author(s):  
Kuk Hyun Song ◽  
Han Sol Kim ◽  
Won Yong Kim
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Grain Refinement ◽  
Transverse Direction ◽  
Effective Strain ◽  
Initial Material ◽  
Rolled Material ◽  
Roll Mill ◽  
Average Grain Size ◽  
Conventional Rolling

This study evaluated the microstructure and mechanical properties enhancement of cross roll rolled Ni-10Cr alloy, comparing with conventional rolled material. Cold rolling was carried out to 90% thickness reduction and subsequently annealed at 700 °C for 30 min to obtain the fully recrystallized microstructure. Particularly, cross roll rolling was carried out at a tilted roll mill condition of 5º from the transverse direction in RD – TD plane. Application of cross roll rolling on Ni-10Cr alloy contributed to the notable grain refinement due to higher effective strain than that of conventional rolling, consequently, average grain size was refined from 135 µm in initial material to 4.2 µm in cross roll rolled material. Furthermore, //ND texture in CRR material was well developed than that of CR material, which contributed to the mechanical properties and formability enhancement.

Microstructure and Mechanical Properties Development in Cross Roll Rolled Ni-30Cr Alloy

2012 ◽  
Vol 706-709 ◽  
pp. 2462-2467
Author(s):  
Kuk Hyun Song ◽  
Han Sol Kim ◽  
Won Yong Kim
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Effective Strain ◽  
Initial Material ◽  
Grain Boundary Character ◽  
Microstructure And Mechanical Properties ◽  
Cold Rolled ◽  
Conventional Rolling ◽  
The Relationship ◽  
Electron Back Scattered Diffraction

In order to evaluate the microstructure and mechanical properties of cross roll rolled Ni-30Cr alloy, comparing with conventionally rolled material, this work was carried out. The materials were cold rolled to 90% in thickness reduction by conventional rolling and cross roll rolling methods and subsequently annealed at 700°C for 30 min. After this work, in order to evaluate the grain boundary character distributions of the materials, electron back-scattered diffraction technique was introduced. The application of cross roll rolling was more effective to develop the microstructure and mechanical properties than those of conventional rolling. As a result, the grain size was significantly refined to 1.3 μm in conventional rolling and 0.6 μm in cross roll rolling, compared to initial material (30 μm), respectively. Also, these grain refinements directly affected an increase in mechanical properties. In the present study, we systematically discussed the relationship between grain size and mechanical properties in terms of an increase in effective strain.

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