Materials physics and mechanics

RAR RUS 85-89 University of Warmia and Mazury in Olsztyn Fraczyk

Olsztyn, Poland

University of Bialystok Breczko

Bialystok, Poland

Study of Crystallization of Fe95Si5 Amorphous Alloy Using XRD and DSC Crystallization of amorphous metallic alloy Fe95Si5 (at. %) was investigated using X-ray diffraction measurements performed in-situ during isothermal annealing. Fe95Si5 ribbons, prepared by melt-spinning, have been analyzed by differential scanning calorimetry (DSC). Their nanostructural evolution has been studied by combining heat treatments with conventional X-ray diffraction. The objective of the experiment was to determine changes in the structural parameters during crystallization of the examined alloy. The crystalline diameter and the lattice constant of the crystallizing phase were used as parameters to evaluate structural changes in the material. FeSi Alloys Crystallization XRD DSC https://mpm.spbstu.ru/article/2010.13.1/ MPM_9_2_P01.pdf

RAR RUS 90-95 Institute of Metal Physics, Ural Branch of RAS Yakovenkova

Ekaterinburg, Russia

Institute of Metal Physics, Ural Branch of RAS Karkina

Ekaterinburg, Russia

Core Structure of Superdislocations and Destruction of the Dislocation Barriers after High-Temperature Deformation of Ti3Al An electron microscopic analysis of the dislocation structure of the Ti3Al intermetallic after high-temperature deformation is performed. It is found that the microstructure of the samples deformed at T = 1073-1173 K contains mobile a, 2c+a and other c component superdislocations. Experimental data are discussed considering results of the computer simulation of the superdislocation core structure in Ti3Al. Ti3Al Superdislocations Dislocation Barriers High-Temperature Deformation https://mpm.spbstu.ru/article/2010.13.2/ MPM_9_2_P02.pdf

RAR RUS 96-104 Vilnius Gediminas Technical University Kačeniauskas

Vilnius, Lithuania

Vilnius Gediminas Technical University Pacevič

Vilnius, Lithuania

Vilnius Gediminas Technical University Katkevičius

Vilnius, Lithuania

DAM Break Flow Simulation on Grid In this contribution we report on a dam break flow simulation on gLite based grid infrastructure. The dam break problem including breaking waves is solved by the pseudoconcentration method improved by interface sharpening technique. The developed interface sharpening procedure helps to preserve interface sharpness and mass conservation. The computed position of the leading edge of water column has been compared with the experimental measurements. DAM break flow simulation Interface sharpening technique https://mpm.spbstu.ru/article/2010.13.3/ MPM_9_2_P03.pdf

RAR RUS 105-110 St. Petersburg State University Prozorova

St.Petersburg, Russia

Influence of Dispersion on Cross Flows in Gaz Mechanics The aim of this paper is to discuss the modified Navier-Stokes equations and to find the reason for appearing the second viscosity and cross flow through the sides of elementary volume at large gradients of the physical values. The modified laws of conservation were obtained for the particles without structure in gas, liquid, and solid taking into account the influence of angular momentum. The equilibrium conditions formulated as the conditions of angular momentum equilibrium for continuous mechanics with boundary conditions were suggested in previous works. The equilibrium conditions for forces are a special case of more general conditions of angular momentum equilibrium and follow from them. We discuss also the problems that can appear if the variation of angular momentum in an elementary volume near a surface takes place. Gaz Mechanics Cross Flows Dispersion https://mpm.spbstu.ru/article/2010.13.4/ MPM_9_2_P04.pdf

RAR RUS 111-134 Peter the Great St. Petersburg Polytechnic University Melker A.I.

St.Petersburg, Russia

Cracks: Challenge to Physics In this contribution we have considered how the mathematical description of cracks was changing. A sketch of the works done in the framework of the theory elasticity and fracture mechanics that have relation to stress concentration around cracks is given. Considerable attention was focused on the physical ideas introduced into the theory of elasticity and fracture mechanics by Griffith and Mott. A sketch of the new approach, molecular dynamics simulations, is also given. It is shown that this approach revealed some features of crack behavior in crystalline and amorphous materials, polymers, and carbon nanotubes that cannot be imagined on the basis of speculative knowledge. At last,we have tried to attract attention to using the theory of solitons for solving nonlinear problems of the theory of elasticity and fracture mechanics. The solitonic theory of a moving crack is thoroughly discussed. Cracks Theory elasticity Fracture mechanics https://mpm.spbstu.ru/article/2010.13.5/ MPM_9_2_P05.pdf

RAR RUS 135-161 Peter the Great St. Petersburg Polytechnic University Melker A.I.

St.Petersburg, Russia

Radiation Damage and Cracks in Solids In this contribution we considered different aspect of brittle fracture of solids under the action of irradiation by powerful pulsed beams of relativistic electrons and neutrons. The fracture of aluminum plates consists of several stages including formation of blisters, craters and laminations; and is accompanied by appearance of a complex system of stresses in the surface layer. Computer simulation by Monte Carlo method revealed that the loose zone containing the main quantity of Frenkel’s pairs does not overlap with the maximum of absorbed energy. Computer simulation by Molecular Dynamics revealed that vacancy clusters can transform into dislocation loops, voids or microcracks in dependence on strain state. A model of brittle fracture of metals suggested incorporates Coulomb’s explosion that generate shock waves. The fracture in the form of chunks induced by neutrons is simulated by Monte Carlo method. It is found that crack interaction can be different, i.e. cracks can attract, repel, and lead to breaking off parts of a material. Radiation Damage Cracks Solids https://mpm.spbstu.ru/article/2010.13.6/ MPM_9_2_P06.pdf

RAR RUS 162-166 United Institute of Informatics Problems of National Academy of Sciences of Belarus Feranchuk

Minsk, Belarus

De Novo Protein Structure Prediction by Simulation of Folding Pathways We have developed a new de novo protein structure prediction algorithm, SKIFOLDING. The search space of the algorithm is built from all the possible combinations of secondary structure elements in a given subset of protein structures databank. Search directions follow the best possible folding pathways, with a simple statistical score function. We tested the algorithm on the ability to distinguish between different families within the immunoglobulin-like type of fold, for 9 proteins with known structure. For the most of tested proteins the correct structure was presented in the program output and false-positive decoys were of worse quality than the correct structure. Modelling Protein structure SKIFOLDING https://mpm.spbstu.ru/article/2010.13.7/ MPM_9_2_P07.pdf