Analiza utjecaja oblika matrice na stanje naprezanja u procesu istiskivanja alumijiskih profila s tankim stjenkama

A theoretical analysis of the effect of die shape on the stress - strain state during hot extrusion of T-section bar of two different aluminium alloys has been carried out in this study. A finite element method-based program, was used for modelling the extrusion process. Tests were carried out to obtain optimal process parameters of extrusion of T-shaped section, at which no deformation of the section occurs. The effect of the antechamber height and the shape as well as arrangements of the die channel on the geometrical shape of the extruded product have been determined.U ovoj studiji je razrađena teorijska analiza utjecaja oblika matrice na naprezanje i deformiranje pri toplom istiskivanju T-profila dviju različitih aluminijskih slitina. Za modeliranje procesa istiskivanja rabljen je program temeljen na metodi konačnih elemenata. Provedena su ispitivanja za optimalne parametre procesa istiskivanja T-profila pri kojima nije došlo do nikakvih deformacija profila. Utvrđen je utjecaj visine pretkomore te oblika i izvedbi kanala matrice na geometrijski oblik istiskivanog proizvoda

Uporaba trodimenzionalne simulacije za razvoj matrica za ekstruziju aluminijskih profila

The automated system of three-dimensional computer simulation with use of FEM is developed. The model is based on the Euler approach. The function of Markov variation principle is used for derivating. The connected task of thermo-viscous-plasticity is solved. The flat die is designed for extrusion of the thin-walled shape from a soft aluminium alloy 6060.Razvijena je automatska trodimenzionalna kompjutorska simulacija uporabom FEM-a. Model se temelji na Eulerovom pristupu. Za deriviranje se koristi funkcija Markovog načela varijacije. Riješen je zadatak termo-viskozne plastičnosti koji je s time povezan. Projektirana je ravna matrica za ekstruziju profila s tankim stjenkama iz mekane aluminijske legure 6060

Theoretical analysis and optimisation of parameters in extrusion process of explosive cladded bimetallic rods

Abstract The article discusses the problem of theoretical choice of the optimal shape of extrusion die and extrusion ratio during the extrusion process of aluminium rods copper cladded with the help of the explosive method to join the core and the coat. Mathematical model of extrusion process based on finite elements method was worked out to attaining the objective. The model makes it possible to carry out the analysis of mechanical state (stress and strain) on the boundary of layers for the sake of main parameters of the process. Optimal values of process parameters were obtained basing on the mathematical analysis for bimetallic rod with outer diameter 18 mm and copper layer thickness 2 mm

Вплив пропелерної модуляції на ефективність просторової режекції завад адаптивними антенами бортових систем зв'язку

Розглянуто проблему впливу пропелерної модуляції на ефективність просторової режекції завад адаптивними антенами бортових систем зв’язку

Development of a method for introducing 1-aminophosphonate fragment in a siloxane matrix

© 2016 Taylor & Francis Group, LLC.A versatile synthetic method for the preparation of 1-aminophosphonate derivatives of methylsiloxane oligomers was developed. The introduction of trimethylsilyl amino protecting groups promotes hydrosilylation. The proposed modeling technique allows entering 1-aminophosphonate fragment into the siloxane skeleton of the matrix structure, as well as into the hydrolytically unstable alkoxy-functionalized organosilicon compounds

Synthesis of methyl(1-aminophosphonate)siloxane oligomers

© 2016, Springer Science+Business Media New York.A synthesis of 1-aminophosphonate derivative of methylsiloxane oligomer was developed. A methodology of the introduction of 1-aminophosphonate fragment not only into the stable siloxane structures, but also into hydrolytically unstable alkoxyfunctional organosilicon compounds was suggested

Synthesis of new organoelement copolymers based on polydimethylsiloxanes and aminophosphonates

© 2018 Based on commercially available 3-Aminopropyl (diethoxy)methylsilane new alkoxysilane with functional aminophosphonate group - diethyl (2-((3-(diethoxy (methyl)silyl)propyl)amino)propan-2-yl)phosphonate were synthesized and characterized. Obtained functional alkoxysilane were transformed to tetrasiloxane in active medium in the presence of acetic acid and then copolymerized with octamethylcyclotetrasiloxane (D4). The chemical structure of the resulting polymer was studied and confirmed by a combination of physical methods, namely,1H,13C,31P and29Si NMR, GPC, and IR spectroscopy. The thermophysical and rheological properties of the polymer were also studied