When selecting technology options for additive manufacturing, it is important to be guided by a list of basic requirements for manufactured parts, powder material features, and the range of equipment specifications. To develop the most effective solution, pilot testing of the technology will be required to determine the preferred process modes that ensure the required quality, cost, and manufacturing time. Accordingly, for such industries, it is important to develop a model that describes the stages of additive manufacturing. In this regard, this paper is devoted to considering the issues of optimization, planning, and management of additive manufacturing technology based on multiple criteria for selecting the most effective technology that involves optimal loading of production facilities. The proposed model introduces indicators that characterize adaptation and allow arguing the practical benefits of using 3D printing technologies. Comparison of process routes by these indicators allows choosing a specific manufacturing route. Having selected the manufacturing option, it is possible to calculate the most efficient placement of products on platforms, as well as to develop a suitable sequence of execution of the main manufacturing operations in order to minimize costs and time expenditures. It was found that the use of the proposed model allows to reduce the manufacturing time of a batch of products by approximately 2.5%. Thus, the proposed model can be useful in additive manufacturing to reduce downtime of installations and speed up the release of products.
Keywords: production organization, productivity assessment, equipment reconfiguration, machine loading, automation, multi-product production
Tests to determine the seismic stability of elements of pipeline systems, in particular pipeline fittings, are included in the list of those necessary to confirm the operability of the element. In this study, a stand was developed for testing to determine the seismic stability of butterfly check valves, which are a type of pipeline fittings. A finite element analysis was carried out, data on maximum deformations, stresses and displacements of structural elements were obtained, and the response of the installation table to seismic impact was calculated. The resulting displacement values of the table structure do not exceed the limit values specified by the technical requirements and do not lead to distortion of the structure or destruction of joints, which makes it possible to move from design to manufacturing and commissioning of the stand.
Keywords: vibration tests, seismic resistance test bench, pipeline, pipeline valves, swing back gate, mathematical modeling, finite element method, strength calculation, simulation modeling, stress-strain state
Due to the constant increase in production, new structural materials development and growing rates of non-renewable resources consumption, the issue of increasing the machinery resource is urgent. Thus, it is necessary to develop technologies for spraying coatings that improve the functional characteristics of products, in particular, impact strength, microhardness, resistance to wear, corrosion and other environmental factors by modifying the surface layer structural-phase state. These technologies application is necessary in strategically important industries, such as machine tool manufacturing, aerospace, automotive, shipbuilding, chemical, energy, etc. This article is devoted to the facility development for multicomponent nanocomposite coatings sputtering. The design and commissioning of such a facility requires a high time and material resources investment. In this regard, it is necessary to use modern computer software systems that allow simulating multiphysics processes that take place during the facility operation. The simulation of the cathode-anode unit was carried out. Based on the simulation results it was shown that it is necessary to take into account the physical processes in the interelectrode region when designing the plasma spraying unit, since the resource of the cathode-electrode unit and the productivity of the sputtering process directly depend on the parameters of the discharge and the resulting plasma jet. Thus, high temperature and current density, as well as the arc spot abrupt movement, lead to increased wear and failure of the copper nozzles. The maximum values of the temperature and velocity of the plasma jet during spraying were 32000 K and 1800 m/s, respectively.
Keywords: plasma spraying, multicomponent nanocomposite coatings, multiphysics processes, mathematical modeling
The problems of the operation of buildings on subsidence soils of the Rostov region are considered. A brief analysis of the methods used to consolidate the soil. Concrete examples of the use of cementation and silicatization of soil bases in the development of reconstruction projects for buildings in the cities of Shakhty and Taganrog, Rostov Region are given. An integrated approach to the choice of technology for fixing the soil base of reconstructed objects is proposed, which provides for the simultaneous consideration of the following factors: - basic physical and mechanical properties of soils; - mineralogical composition of soils; - change in the state of the soil base during the operation of the building (local decompression, erosion, chemical and mechanical suffusion, etc.); - chemical composition and groundwater level, forecast of their change; - terrain, the danger of activation of landslide processes; - the presence of retaining walls and other retaining structures in the zone of influence, assessment of the loads on them in the process of consolidation; - the technical condition of building structures of the building, including its underground part and the blind area; - the status of the reconstructed object. With special care and precaution, it is necessary to choose the technological and design parameters of soil consolidation for cultural heritage sites of federal or regional significance; - technical and economic indicators.
Keywords: subsidence of soils, strengthening of soils, fixing of soils, cementation, silicatization, Geology, construction, cultural heritage object
The methods of injection fixing the soils of the base under the foundations of cultural heritage are considered. The specific examples show the features of soil consolidation by cementation and silicatization methods. The technological features of soil consolidation, taking into account the material of the foundations and the technical condition of cultural heritage sites are given
Keywords: cementation, silicatization, injector, soil, consolidation, foundation, object of cultural heritage, sediment, subsidence, deformation
The analysis of the projects for securing the soil foundations, which are part of the new construction projects of educational institutions in the Rostov region in 2016-18, is carried out. On the example of the construction of schools in the cities of Rostov-on-Don, Taganrog, Shakhty, Novocherkassk, Aksai and the village of Chaltyr, the main technical and technological solutions for soil consolidation are considered, depending on the engineering and geological conditions of the construction sites
Keywords: cementation, injector, soil, consolidation, foundation, soil piles, retaining walls, sediment, subsidence, deformation