Authors: Viktoriya Pasternak, Artem Ruban, Nina Zolotova, Oleg Suprun
Abstract: The article describes in detail the process of modelling an inhomogeneous environment. It should be noted that the modelling of a rectangular plate is justified by the Kirchhoff – Love methods. A special feature of this simulation with the intervention of the Abaqus software package was the setting of different steps at different points in time. We also constructed H-adaptive schemes of finite element methods and their triangulation with different steps and with pre-guaranteed accuracy. When adapting the grid at the places of the greatest errors, a local thickening of the Triangle grid was observed, which ultimately determines that the structure of the desired solutions contains features in the edges of the vertices of the fixed edge. We also found that the proximity to linear growth of the number of nodes and finite elements in the initial stages of adaptation slows down their growth in the final stages. It should also be noted that the proposed H-adaptive schemes of ITU using the Abaqus software package with pre-guaranteed accuracy of calculating approximations showed satisfactory results, since they obtained a final deviation error of 2%. Also, a detailed description of the step-by-step adaptation results allowed us to generate the reliability of the proposed schemes with different steps.
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Authors: Artem Bychenko, Maksym Udovenko, Vitalii Nuianzin, Andriy Berezovskyi
Abstract: Development of a functional model of the process of creating a knowledge base on the recognition of objects and actions of the enemy on the basis of neural networks and fuzzy logic. The aim of the work is to develop a set of software and hardware designed for remote identification of hazardous substances by machine visual recognition of information signs of dangerous goods with the output of relevant information to the means of visual display (interface). Recommendations concerning providing UAVs with the necessary technical means to monitor the zone of emergencies are analyzed. The recommendations of the organization of radio communication between the UAV and the operator depending on the range of the UAV departure, terrain conditions etc are analyzed and given. The structural scheme of the complex of remote recognition of HC in the form of blocks, units and software and hardware is developed. As a result of the analysis of programming systems, it was found that Python programming language is the best choice to ensure the full operation of the software due to the built-in capabilities and the involvement of third-party frameworks. A database containing information on more than 3.000 HCs with detailed recommendations for emergency response is developed. The hardware and software complex for remote identification of dangerous substances by machine visual recognition of information signs of dangerous goods by UAV, consisting of unmanned aerial platform with photo-video recording means, data transmission system to ground control station, PC for processing results and related software are substantiated and developed. A test of the UAV's capabilities in recognizing danger signs with UN numbers in different lighting conditions was tested. In all cases, the HC was accurately identified. The ideas and methods proposed in this article will allow to create cheap and simple tools for rescue units of Ukraine, which deal with the consequences of emergencies related to the leakage of HCs.
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Authors: V.D. Galdina, N.S. Galdin
Abstract: The paper presents the studies on the compositions selection and properties of polymer-bitumen binders obtained using the viscous petroleum bitumen, styrene-butadiene-styrene polymer and plasticizer according to the experimental planning method. Regression equations of the polymer-bitumen binders processing and performance properties, which make it possible to optimize the compositions and predict their properties taking into account the operating conditions, were obtained. Polymer-bitumen binders in comparison with the properties of viscous road bitumen have the increased indicators of heat resistance, crack toughness, ductility and elasticity. To obtain the adequate mathematical model, the experimental data were processed, compositions were optimized and dependence diagrams were constructed by using the Maple software package. The software for a personal computer including the algorithm and program for selecting the polymer-bitumen binders has been developed. When using the software it is possible to automate the calculation of the polymer-bitumen binders compositions with a given set of technical properties.
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Authors: O.S. Sirotkin, R.O. Sirotkin, M.Yu. Perukhin
Abstract: Nowadays, a lot of information on structure and properties of a wide variety of substances and materials has been accumulated. Yet, there is a lack of systemic universal approaches to assessing their structure and properties, including developing the effective approaches for monitoring and analysing various materials. It is of special interest in this respect to assess the effects of the chemical bond type on structure and properties of substances and materials. However, searching for necessary data on the effects of chemical bonds on structure of substances and materials is a rather laborious process. The authors, relying on the intermediate nature of chemical bonds of compounds of elements in any metallic and non-metallic material, as well as the system of chemical bonds and compounds developed by them in the form of a “Chemical Triangle”, produced an algorithm for creating a computer programme. It implies systematising of the database on the effect of chemical bond type on its length and energy, structure and various physicochemical and mechanical properties of homo-and heteronuclear compounds and materials. Development of such a specialised computer programme greatly simplifies this process, providing more efficient analysis and control of materials.
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Authors: Jakub Holan, Radek Štefan
Abstract: The problem of heat transfer in solid materials can be described by the well known transient heat transfer equation. However, as the problem is strongly non-linear, the solution to this equation generally cannot be determined directly. Various numerical approaches have been proposed and employed by various authors for solving the problem.However, most of the available numerical solvers are limitedly available as they are often not free to use, they have to be installed, and they are too complex.This paper presents a new web-based solver for the problem of heat transfer over the thickness of a concrete slab during fire developed by the authors.The computational algorithm is based on the finite difference method and implemented using JavaScript.A graphical user interface for the input of user-defined parameters and for the interpretation of results is created using HTML.The paper also briefly presents the theory behind the computational algorithm.Moreover, examples of various problems solved by the web-based solver are presented in the paper.A brief parametric study of the effect of initial density of the material on the temperature distribution in the slab during fire is also presented. From the presented figures and examples, it can be readily seen that the newly developed web-based solver for the assessment of temperature distribution over a slab thickness during fire is user-friendly, easy to use, highly accessible, fast, and intuitive.
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Authors: Alexandra Gabriela Ene, Carmen Mihai
Abstract: Worldwide, natural fiber insulation is in high demand, offering not only thermal comfort but also soundproofing. Another important aspect for which these biodegradable materials is popular is that it presents no health risk. Due the soft texture, natural fibers can be introduced very simply in any type of construction. Regardless of the vertical or inclined mounting, the stapling or gluing of the material gives stability. For example, the wool insulation is made from natural fibers, washed and treated. These wool fibers are held together either mechanically or using up to 12% polyester fibers to form semi-rigid tiles/mattresses or rollers. With a higher price than mineral wool, natural insulation is ideal for eco-friendly wooden houses. Depending on the type of construction, the wool can be mounted in a single layer or several layers, of different thicknesses [1]. For the evaluation of the thermal efficiency of the wool panel’s insulation four variants of insulating panels based on 100% wool were accomplished. Using a specialized simulation program, it is found that the heat losses through the walls themselves represent 86% of the total heat loss and the heat losses through the windows/doors to the outside represent 14% of the total heat losses.
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Authors: V.D. Galdina, N.S. Galdin
Abstract: When selecting the compositions and studying the properties of the activated mineral powders based on superacid fly ash, mineral and organic activating agents, the computer modelling was performed. The activated mineral powders compositions corresponding to the properties of GOST 32761 2014 requirements to the MP-1 activated mineral powders of carbonate rocks were selected using the experiment mathematical planning method. When processing the experimental data for obtaining the adequate mathematical model, optimizing the compositions and constructing the graphical dependencies, the Maple package was used. The software for the personal computer including the algorithm and se-lection program of the activated mineral powders compositions was developed. The software makes it possible to automate the calculation of the activated mineral powders formulas with the specified technical properties.
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Authors: Adriana Ionescu, Mihai Negru, Cristian Oliviu Burada, Ramona Pinţoi
Abstract: For a building equipped with anti-seismic devices, the value of the damping force of the dampers positioned at the superstructure is very important for an efficient anti-seismic damping and therefore an optimization of the seismic protection system with dampers is required. There are several configurations for placing the dampers that amplify the displacement and the damper axial force. This paper presents a computational mathematical model made for determining the coefficients of displacement multiplication and the damping force multiplication for two special positioning configurations of the antiseismic dampers using levers. Based on this model, a software program was created that allows to choose the geometrical parameters of two configurations of dampers placement having as criterion of choice the value of the amplification coefficient of the dampers displacement or the damper axial force.
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Authors: Ilya Nikolaevich Udin, A.A. Voropaev, A. Unt
Abstract: Laser technologies deservedly take their place in modern mechanical engineering production. Using laser source for welding has already become common. However, the creation of critical welded constructions is impossible without extensive technological surveys, which can be greatly simplified by using a computational experiment. To achieve this goal, special programs are usually used. That can be unjustified difficult and thereby awkward for technological practice. The article describes an application built on the basis of a simplified model for calculating the temperature field for the cases of laser and laser-arc welding of internal fillet welds as well as single-sided T-joints and simultaneous double-sided welds. The results of calculations by the model and comparing them with experimental data have shown that it is sufficiently adequate for use in technological purposes. The developed application contemporaneously has a simple and intuitive interface, does not require significant computational resources and can be used for quick preliminary estimation of the result of welding for the selected type of weld.
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Authors: T.Yu. Chernysheva, A.A. Zakharova, E.V. Telipenko, E.V. Molnina
Abstract: The possibilities of using nanomaterials and nanocoatings for machine building are considered. The review of software for engineering calculations of welding processes and heat treatment is carried out. A decision support system for choosing a rational amount of nanostructured modifier powders for welding corrosion-resistant steels is proposed.
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