Application of BIM technology for surveying heritage buildings

The preservation of heritage buildings is beyond doubt an important problem of today. The examination of a heritage building involves a number of problems, viz. missing design documentation, the need to find extant reports about technical condition of the building structures and building reconstruction projects prepared by different organizations, and nonconformance of data contained in drawings and documents of different organizations. In this paper the abovementioned problems are reviewed exemplified by the case of the federal heritage-listed building "Ekaterinburg State Academic Opera and Ballet Theatre", Yekaterinburg. The paper proposes the use of solutions based on information modeling methods for the examination of structures of the abovementioned building and reviews the possibility of employing these methods for upkeeping the building. The article demonstrates the practical value of the proposed application of a BIM model method comprising the building reconstruction stages for the structure survey on a specific example. The method proposed in the paper has a great practical value and can be employed for the improvement of normative and technical documentation, heritage building survey works, and for creating design documentation for restoration of buildings

Modernization of the fuel supply system in the internal combustion engine by electronic control of the ring valve

The research was carried out in order to develop a method for skipping fuel supplies (turning off individual piston strokes) at low frequencies of crankshaft rotations and at partial engine operating modes with direct-acting fuel supply systems to increase fuel efficiency. The developed method is easily implement using a ring-type discharge valve with electronic control. A valve made in the form of a split elastic ring and installed in a high-pressure line above the plunger pair controls the fuel supply. An electromagnet, located in the cavity of the annular valve, controls the valve, using an electronic regulator, acting at the right moment according to the signals coming from the sensors of the engine crankshaft speed, the volume of incoming air and the position of the piston. The proposed direct-acting fuel supply system with an electronically controlled ring valve reliably ensures the speed and load characteristics of the engine by affecting the number of cyclic feeds. With a decrease in the load and speed of the engine crankshaft, the number of cyclic fuel supplies decreases due to a decrease in signals sent to the electromagnet winding and, as a result, the valve does not attract the fuel and misses the fuel supply. Reducing the unevenness of the fuel supply by the dynamic component that occurs when the supply is switch off is ensured by reducing the inertia of the regulator due to the electronic control of the ring valve. The developed mathematical model of a direct-acting fuel supply system with an annular discharge valve allows us to reveal the relationship of fuel supply parameters with the design dimensions of the split ring. Such direct-acting fuel supply system with an electronically controlled discharge valve allows, due to the skipping of working strokes in low-load and idle modes, redistributing the provided amount of fuel to the working cylinders, significantly reducing fuel consumption

Application and research twin roll casting-extruding process for production longish deformed semi-finished products from aluminum alloys

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.At present, Russia is actively developing methods of combined treatment of aluminum alloys, one of which is the method of twin roll casting-extruding. It is very suitable for processing aluminum alloys having a relatively low melting point. The method consists in pouring a melt into the rotating rolls, crystallizing it on the roll surfaces, rolling with a predetermined reduction amount, pressing out in front of the die and squeezing out the product of the predetermined configuration and dimensions through it with drawing ratio in the range of values 10-40. Analysis of technical and economic indicators showed that this method has a number of advantages in comparison with traditional technologies of semicontinuous extruding and continuous castingrolling. So the output of a good metal at high production volumes can reach 95-97% at a productivity of up to 3-4 tons per hour. In addition, it is possible to quickly move from one profile size to another by changing the matrix. The authors proposed and patented various designs and methods for producing solid and hollow press products from non-ferrous alloys. On their basis, laboratory and pilot-industrial units for combined processing have been created, on which experimental studies have been carried out to obtain long-dimensioned deformed semi-finished products from aluminum alloys series 5xxx, 6xxx, 8xxx and others. The energy-power parameters of the process are determined and found that they are significantly smaller in comparison with traditional technologies (in 10-50 times). Investigations of the mechanical characteristics of press products have been carried out, which showed that when implementing such a treatment scheme, even when producing extruded products from low-plastic alloys, they have a high level of plastic and strength properties. Developed technologies based on the method twin roll casting-extruding now are tested in a laboratory of combined treatment methods in School of Non-ferrous Metals and Material Science in Siberian federal university and industrial conditions of a number of metallurgical plant

Computer Modeling and Analysis of the Energy-Power Process Parameters of the Combined Machining of Alloys Al-Mg System

Article shows the results of studies of the process of combined rolling-extruding of an alloy of the Al-Mg system (AlMg6) under various temperature-speed and deformation conditions. Calculations shows that with increasing metal temperature at the entrance to the deformation center, the values ​​of the forces on the rolls and the die decrease, the increase in drawing leads to an increase in the values ​​of forces on both the rolls and the die, and an increase in the deformation rate leads to hardening of the metal and increasing energy parameters of the process of combined machining. However, the maximum extruding force on the combined machining units is 5-10 times lower than the efforts to obtain the same press products on hydraulic presses. A computer model of the combined machining process created with the help of the DEFORM 3D complex, the analysis of the metal flow is made, the temperature distribution of the metal over the section of the workpiece invstigated when producing round bars of different diameters. Shaping of the metal corresponds to the data of experimental and theoretical studies, while the deformation center has a characteristic appearance, including the gripping zones of the workpiece and its rolling, repressing and extrusion. The peculiarity for this alloy is that with a drawing ratio of μ = 3.7 and a strain rate of ξ = 0.78 s-1, the steady extruding process takes place without completely filling the deformation zone from the side of the roll with a protrusion. An increase in drawing ratio or strain rate leads to a decrease in the contactless zone or to its absence. The change in metal temperature also depends on the presence of a contactless zone, which contributes to an increase in heat transfer from the billet to the rolls. The results of the research were used to develop the technology for the production of welding wire from Al-Mg system alloys

Application of BIM technology for surveying heritage buildings

The preservation of heritage buildings is beyond doubt an important problem of today. The examination of a heritage building involves a number of problems, viz. missing design documentation, the need to find extant reports about technical condition of the building structures and building reconstruction projects prepared by different organizations, and nonconformance of data contained in drawings and documents of different organizations. In this paper the abovementioned problems are reviewed exemplified by the case of the federal heritage-listed building "Ekaterinburg State Academic Opera and Ballet Theatre", Yekaterinburg. The paper proposes the use of solutions based on information modeling methods for the examination of structures of the abovementioned building and reviews the possibility of employing these methods for upkeeping the building. The article demonstrates the practical value of the proposed application of a BIM model method comprising the building reconstruction stages for the structure survey on a specific example. The method proposed in the paper has a great practical value and can be employed for the improvement of normative and technical documentation, heritage building survey works, and for creating design documentation for restoration of buildings

Continuously tunable middle-IR bandpass filters based on gradient metal-hole arrays for multispectral sensing and thermography

Continuously tunable middle-infrared bandpass filters have been developed based on gradient metal-hole arrays with two distinct geometries. The rotation filter relies on an array of metal holes with gradually changing periods and hole sizes in the azimuthal direction, while the translation filter exploits a metal-hole array with a linear gradient. The filters are fabricated in a Ti film on a ZnSe substrate using electron- beam nanolithography. They are characterized experimentally using Fourier-transform infrared spectroscopy, and the observed results are compared with numerical predictions of the finite element method. The developed filters offer wide spectral tunability when operating with a focused beam. Particularly, the central wavelength of the transmission band is tunable in the λc [ ð9, 15Þ μm range, for the rotation filter, and in the λc [ ð8, 13Þ μm range for the translation one, as a linear function of the filter angular or linear displacement. The filters feature relatively broad bandwidths of Δλ ≃ 0:2λc, while their spectral contrast and energy efficiency depend on the gradient type. The filter spectral response function shape and the extent of its spectra tunability can be further optimized by judicious design of the hole geometry and the metal-hole array gradient, respectively. The developed filters hold strong potential in the infrared multispectral sensing and imaging, thanks to their conceptual simplicity. Considering the linearity of Maxwell’s equations and availability of appropriate technologies for the fabrication of gradient arrays of sub-wavelength metal holes, the developed concept can be translated to other spectral ranges