Abstract: The Institute of Civil Engineering of the "Ural Federal University Named after the first President of Russia B.N. Yeltsin" (UrFU) has carried out the research to improve the deformation-strength characteristics of the most common building material, i.e. concrete. One method to improvement the properties is the disperse reinforcement of the entire volume of concrete with fine fibers. The research and mathematical modeling of the dependence of the characteristics of the composite material on the properties of the dispersed phase (the properties of the fiber material of the fiber) and the dispersion medium (the structure of the concrete) will allow in-situ prediction of the strength of the structures being manufactured and to determine the ratio and quality of the raw feed components of the mixture.
Abstract: Functional enhancement of concrete, giving it heat-resistant properties becomes possible while adding mill ground additions based on silicon carbide materials of the region. The selection of silicon carbide waste and secondary production materials as a filler for the production of concrete with heat-resistant properties was based on the following principles: dispersion, the chemical composition, phase composition that reflect the chemical activity of the material in relation to the concrete binder. The thermal resistance of concrete has increased fivefold. In forming concrete structures with addition of silicon carbide occurs embedding into the structure of hydrates fine powder silicon carbide cyclone dust, with the chemical processes behaviour in the boundary contact zone between binder and filler. The increase of thermal resistance can attribute the resulting concrete composition to the category of heat-resistant concretes, and that significantly expands the functionality of concrete.
Abstract: In this paper, based on the gas-kinetic theory of plasma, a theoretical analysis of the possibility of forming a plasma state in melting channel as a result of the interaction of high-energy electrons of the electron beam with the atoms of the material, being processed in melting channel (in free state) is proposed. Also the assessment of a possible impact of this process on the quality of weld metal is given. It is shown that if we take the electron-beam welding of large thickness with formation of a knife-form melting zone, the occurring processes can develop both in the direction of self-organization (synergetic, evolution) and chaotically (it all depends on the set of after-effects, caused by them, and their duration), which is manifested either as autofocusing and melted depth increase (synergy, evolution) or as formation of defects in the center of the channel (in the central part of the weld) in the form of steam and gas cavities of quite considerable size.
Abstract: The technology of wood waste processing to obtain a construction material is presented. Thermo-modified ground bark as a filler and gypsum as a binder were used in the composite. The experimental studies to determine the strength and water absorption of the composite material of the filler concentration and the fractional composition were presented. The analysis of the results was conducted.
Abstract: A new technology of metal billets production by molding and thermal treatment of compositions based on iron powders of medium dispersion, fine powders of iron oxide, and the thermosetting binder, which provides for the required physical and mechanical properties of the material, is proposed. It is found that, at a certain concentration and dispersion of the components of the solid phase, the injection and direct compression molding of parts of complex shape (similar to the MIM-technology) is possible at pressures from 70 MPa to 100 MPa ensuring uniform density over the cross section. The established stages of thermal treatment of compositions, thermal behavior and protective medium ensuring uniformity of products, and chemical composition of the product material are presented in the paper. The experimental and theoretical studies of the dimensional accuracy of steel products obtained by the developed technology were carried out, and it was discovered that the produced parts were of the precision of steel parts produced by MIM-technology.
Abstract: The study presents a comparative analysis of consumer properties of platinit by different producers. Both the products of Russian companies and the foreign counterparts are considered. It was established that the domestic platinit, though not very different in composition from its foreign analogues, is still inferior to them in its parameters, such as physical and technological properties, as well as surface quality.
Abstract: Thermal modification is a modern demanded technology allowing receiving natural environmentally friendly material with increased bioproofness and dimensional stability. However, the known technologies of heat treatment of massive wood are rather power-intensive therefore an urgent task is to decrease the energy consumption rate of this process. For this purpose the authors have suggested the technology at which the flue gases, received by gasification of waste of the wood processing industry, act as the agent of processing. The results of the research of this process are presented in the article, the rational modes of processing for concrete types of timber (oak, pine and birch, thickness from 30 to 60 mm) are defined and also the interrelation between the moist characteristics of the wood fuel used for receiving flue gas and the technological modes of processing of massive wood are established. It is also defined that the thickness and breed of material, namely the maintenance of pentosanes as a part of the modified wood exerts impact on the process of thermal decomposition of timber.
Abstract: The article highlights the results of a study of the sorption capacity of some types of carbon fiber materials (CFM) with respect to the ions of heavy metals and oil products. A sorption method for the wastewater treatment, which allows cleaning the wastewater from oil products, ions of heavy metals, and other pollutants to the MPC, was suggested, and some recommendations for the implementation of the method were given. It was found that the use of CFMs for the sorption of heavy metal ions and oil products was more effective than that of some other known sorbents. The regeneration possibility of CFM, simplicity, and variability provide for a number of advantages compared to other known methods. The suggested method can be implemented both as a standalone and in conjunction with other methods to improve the biological treatment of wastewater.
Abstract: The paper presents the findings of the research into neoprene-like soft foamed materials during compression in water. The specific features of the internal structure of such materials lead to complex deformations. This is related to the specific features of the internal structure of materials that contain a large amount of inert air. The paper also presents the findings of structural studies which explained the relationship between the elastic properties of materials and the strength of polymer bonds forming internal air cavities. When foamed the polymer sections are destroyed under compression, it results in the loss of enclosed volume of air voids. This changes the total volume and thickness of the material, which defines some physical and thermal properties of products made of such material. Hydrostatic pressure environments have their own specific features. Rheological properties of soft polymers in a hydrostatic pressure environment give rise to a composite effect of compression deformation. The study of recent developments in the research into polymer deformations in a hydrostatic pressure environment shows that it is difficult to record the stages of reversible and nonreversible compression deformation in near-real experimental simulation of diving operations. The paper presents the developments and findings of experimental design studies for a product (wetsuit) made of foamed materials that were conducted in a hydrostatic pressure environment in an enclosed volume using special Drucktank equipment by the Marine Engineering Department of the University of Rostock
Abstract: To numerically solve a problem of stress-strain state of a workpiece metal under roll forming, finite element analysis was used that allowed using the principle of elastic-plastic deformations with a multilinear hardening curve. Numerical results of base metal lift have been analyzed and the adhesion strength of antifriction coatings and a steel base has been determined. Some recommendations have been made on optimal diameter choice of a workpiece subjected to the skew mesh roll forming