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Akhundov V.M.,National Metallurgical Academy of Ukraine
Mechanics of Composite Materials | Year: 2015

The two-level carcass theory as applied to fibrous media under large elastic and plastic deformations of matrix and fibers is expounded. The theory is incremental in its character and takes into account the deformation prehistory of the matrix and fibers in the composite media. At the macromechanical level of analysis, the geometrical equations of macroscopic deformations and the equations of macroscopic motion are defined in an incremental form. At the micromechanical (locally structural) level, incremental microboundary-value problems are solved for nodal material blocks on the basis of carcass deformations and their increments. From the internal fields found, the macroscopic stresses are determined, which allows one to close the system of equations of the macromechanical level of analysis. © 2015 Springer Science+Business Media New York

Malyi E.I.,National Metallurgical Academy of Ukraine
Coke and Chemistry | Year: 2014

If coal is modified by the volatile products formed in pyrolysis, high-quality blast-furnace coke may be produced from batch with a smaller proportion of expensive clinkering coal. In such coking, the batch is modified in the coking chamber; its clinkering properties are improved as a result of partial hydrogenation. New parameters are proposed to describe the modification of the batch; the variation in clinkering properties is established as a function of these parameters. The quality of the coke obtained from modified coal batch is assessed. The relationship between coke quality and the batch composition is determined. The formulas obtained may be used to predict coke quality. Tests show that partial hydrogenation improves coke quality © 2014, Allerton Press, Inc.

Akhundov V.M.,National Metallurgical Academy of Ukraine
Mechanics of Composite Materials | Year: 2015

Based on applied and two-level (carcass) theories, results obtained by solving the problem on cylinders with two- and three-orthogonal reinforcement schemes, where fibers are oriented in the longitudinal, circumferential, and radial directions, under the action of inertial forces caused by rotational motion are presented. The results obtained by both the theories are compared, from which follows the possibility of application of the applied theory to the investigation of bodies highly filled with fibers. © 2015, Springer Science+Business Media New York.

Akhundov V.M.,National Metallurgical Academy of Ukraine
Mechanics of Composite Materials | Year: 2014

The results of research into regularly fiber-reinforced bodies under large deformations, obtained by using a single-level applied and two-level carcass theories, are presented. Uni-, two-, and three-directionally reinforced bodies of revolution and prismatic ones, with high and low content of reinforcing fibers, subjected to butt-end torsion under the action of compression and rotation-caused centrifugal forces are investigated. Problems on the butt-end torsion of a thick-wall cylinder with axially arranged fibers and of a thick-wall toroidal shell with meridionally located fibers are considered. © 2014 Springer Science+Business Media New York.

Svyetlichnyy D.S.,AGH University of Science and Technology | Mikhalyov A.I.,National Metallurgical Academy of Ukraine
ISIJ International | Year: 2014

The paper presents three-dimensional frontal cellular automata (FCA) based model for modeling of microstructure evolution during technological processes. It is hierarchical system. The first level is FCA, the second level is modules of microstuctural phenomena; and the third level is models of technological processes. The phase transformation module (PTM) is one of the components of the second level. PTM will contain several models of phase transformation; one of them presents transformation of austenite into ferrite and perlite. This phase transformation controlled by diffusion is considered as the nucleation and the growth of grains of other phases. The nucleation algorithm is presented in the paper. An effect of nucleation sites on final microstructure was studied on three extreme nucleation variants: nucleation on the boundaries, on the edges and in the grain corners. Simulations have been carried out for low cooling rate and relatively long time of the holding at appropriate temperature. The simulation results of the microstructure evolution studies are presented in the paper. © 2014 ISIJ.

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