scholarly journals Experimental and Theoretical Prediction Model Research on Concrete Elastic Modulus Influenced by Aggregate Gradation and Porosity

2021 ◽  
Vol 13 (4) ◽  
pp. 1811
Author(s):  
Guohui Zhang ◽  
Zhendong Yang ◽  
Yizhi Yan ◽  
Mingming Wang ◽  
Liang Wu ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Aggregate Size ◽  
Expanded Polystyrene ◽  
Polystyrene Sphere ◽  
Aggregate Gradation ◽  
Model Research ◽  
Consistent Model ◽  
Proposed Model ◽  
Self Consistent ◽  
Multiphase Composite

In this research, we developed a four-phase model, which takes the aggregate gradation and porosity into account in the prediction of the elastic modulus of concrete, based on the micromechanical theories. The model has been verified with experimental results. First, using the Mori Tanaka and the differential self-consistent (DSC) methods, the pores in both the mortar and interfacial transition zone (ITZ) were homogenized. Then, the continuously graded aggregates were divided into finite aggregate size intervals. Further, using the generalized self-consistent model and multiphase composite model derived from the Mori Tanaka method, an aggregate gradation model for the prediction of the elastic modulus of concrete was developed. By simulating the pores in concrete with expanded polystyrene sphere (EPS) grains, the effect of overall porosity on the elastic modulus of concrete was investigated. The research results show that aggregate gradation and porosity have remarkable influence on the elastic modulus of concrete, and the proposed model is effective to estimate the elastic modulus of concrete, the deviation between the predicted elastic modulus and experimental elastic modulus is less than 8%. The elastic modulus decreases with increasing ITZ porosity. However, for ITZ porosity exceeding 40%, the decrease in the elastic modulus is large with increasing ITZ porosity. For a fixed overall porosity, the ITZ porosity owned more influences than the mortar porosity on the elastic modulus of concrete. Enhancing the ITZ elastic modulus and decreasing the ITZ thickness are efficient in increasing the elastic modulus of concrete.

THEORY AND SELF-CONSISTENT MODEL OF DUST-DRIVEN WINDS

2002 ◽  
Vol 5 ◽  
pp. 65-65
Author(s):  
S. Liberatore ◽  
J.-P.J. Lafon ◽  
N. Berruyer
Keyword(s):  
Consistent Model ◽  
Self Consistent

scholarly journals Stellar Flares: Observations and Theory

1989 ◽  
Vol 104 (2) ◽  
pp. 49-52
Author(s):  
Suzanne L. Hawley
Keyword(s):  
Scaling Law ◽  
Dynamic Scaling ◽  
X Ray ◽  
Temperature Distributions ◽  
Photometric And Spectroscopic Observations ◽  
Stellar Flares ◽  
Consistent Model ◽  
Self Consistent ◽  
Flare Model ◽  
Large Flare

AbstractPhotometric and spectroscopic observations of a very large flare on AD Leo are presented. A self consistent model of a flare corona, transition region and chromosphere is developed; in particular the chromospheric temperature distributions resulting from X-ray and EUV irradiation by coronae of various temperatures are determined. The predicted line fluxes in Hγ are compared to the observed line fluxes to find the coronal temperature as a function of time during the flare. This run of temperature with time is then compared with the predictions of an independent theoretical flare model based on a dynamic scaling law (see paper by Fisher and Hawley, these proceedings).

scholarly journals A Self‐Consistent Model for Sorption and Transport in Polyimide‐Derived Carbon Molecular Sieve Gas Separation Membranes

2020 ◽  
Vol 132 (46) ◽  
pp. 20523-20527
Author(s):  
Oishi Sanyal ◽  
Samuel S. Hays ◽  
Nicholas E. León ◽  
Yoseph A. Guta ◽  
Arun K. Itta ◽  
...  
Keyword(s):  
Gas Separation ◽  
Molecular Sieve ◽  
Carbon Molecular Sieve ◽  
Separation Membranes ◽  
Gas Separation Membranes ◽  
Consistent Model ◽  
Self Consistent

scholarly journals Flexural behavior of composite structural insulated panels with magnesium oxide board facings

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Łukasz Smakosz ◽  
Ireneusz Kreja ◽  
Zbigniew Pozorski
Keyword(s):  
Magnesium Oxide ◽  
Material Model ◽  
Expanded Polystyrene ◽  
Flexural Behavior ◽  
Joint Analysis ◽  
Model Parameters ◽  
Fe Model ◽  
Computational Results ◽  
Four Point Bending ◽  
Proposed Model

Abstract The current report is devoted to the flexural analysis of a composite structural insulated panel (CSIP) with magnesium oxide board facings and expanded polystyrene (EPS) core, that was recently introduced to the building industry. An advanced nonlinear FE model was created in the ABAQUS environment, able to simulate the CSIP’s flexural behavior in great detail. An original custom code procedure was developed, which allowed to include material bimodularity to significantly improve the accuracy of computational results and failure mode predictions. Material model parameters describing the nonlinear range were identified in a joint analysis of laboratory tests and their numerical simulations performed on CSIP beams of three different lengths subjected to three- and four-point bending. The model was validated by confronting computational results with experimental results for natural scale panels; a good correlation between the two results proved that the proposed model could effectively support the CSIP design process.

scholarly journals The Rules for the Lattice Rotation Accompanying Slip as Derived From a Self-Consistent Model

1999 ◽  
Vol 31 (4) ◽  
pp. 217-230 ◽  
Author(s):  
R. A. Lebensohn ◽  
T. Leffers
Keyword(s):  
Solid Mechanics ◽  
Grain Shape ◽  
Rolling Plane ◽  
Lattice Rotation ◽  
Consistent Model ◽  
Plane Strain Deformation ◽  
Self Consistent ◽  
The One ◽  
Equiaxed Grains ◽  
Very High

The rules for the lattice rotation during rolling (plane strain) deformation of fcc polycrystals are studied with a viscoplastic self-consistent model. Very high values of the ratesensitivity exponent are used in order to establish Sachs-type conditions with large local deviations from the macroscopic strain. The lattice rotation depends on the grain shape. For equiaxed grains the lattice rotation follows the MA rule, which is the one normally used in solid mechanics. For elongated and flat grains the lattice rotation follows a different rule, the PSA rule. In the standard version the model performs a transition from MA to PSA with increasing strain. There is avery clear difference between the textures resulting from the two different rules. MA leads to a copper-type texture, and PSA leads to a brass-type texture.

scholarly journals Self-consistent model for ambipolar tunnelling in quantum-well systems

1995 ◽  
Vol 10 (5) ◽  
pp. 577-585 ◽  
Author(s):  
C Presilla ◽  
V Emiliani ◽  
A Frova
Keyword(s):  
Quantum Well ◽  
Consistent Model ◽  
Self Consistent

A self-consistent model for polycrystals undergoing simultaneous irradiation and thermal creep

1999 ◽  
Vol 79 (10) ◽  
pp. 2505-2524 ◽  
Author(s):  
P. A. Turner ◽  
C. N. Tomé ◽  
N. Christodoulou ◽  
C. H. Woo
Keyword(s):  
Thermal Creep ◽  
Consistent Model ◽  
Simultaneous Irradiation ◽  
Self Consistent

scholarly journals Dynamics of Alfvén waves in partially ionized astrophysical plasmas

2009 ◽  
Vol 76 (3-4) ◽  
pp. 305-315 ◽  
Author(s):  
DASTGEER SHAIKH
Keyword(s):  
Energy Transfer ◽  
Fluid Model ◽  
Propagation Speed ◽  
Neutral Atoms ◽  
Astrophysical Plasmas ◽  
Exchange Processes ◽  
Consistent Model ◽  
Self Consistent ◽  
Partially Ionized ◽  
Energy Equations

AbstractWe develop a two dimensional, self-consistent, compressible fluid model to study evolution of Alfvenic modes in partially ionized astrophysical and space plasmas. The partially ionized plasma consists mainly of electrons, ions and significant neutral atoms. The nonlinear interactions amongst these species take place predominantly through direct collision or charge exchange processes. Our model uniquely describe the interaction processes between two distinctly evolving fluids. In our model, the electrons and ions are described by a single-fluid compressible magnetohydrodynamic (MHD) model and are coupled self-consistently to the neutral fluid via compressible hydrodynamic equations. Both plasma and neutral fluids are treated with different energy equations that adequately enable us to monitor non-adiabatic and thermal energy exchange processes between these two distinct fluids. Based on our self-consistent model, we find that the propagation speed of Alfvenic modes in space and astrophysical plasma is slowed down because these waves are damped predominantly due to direct collisions with the neutral atoms. Consequently, energy transfer takes place between plasma and neutral fluids. We describe the mode coupling processes that lead to the energy transfer between the plasma and neutral and corresponding spectral features.

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