Load switching between main power grid to the backup grid by standard automatic transfer switch

PURPOSE. To develop a variant of the algorithm for the automatic input of the reserve, which consists in transferring the load in case of emergency situations, to make a simulation model in the MatLab® environment corresponding to the developed generalized electrical scheme of the system.METHODS. When solving the problem, the method of digital modeling was used, which consists in the maximum approximation of the system under study to a real object, implemented by means of MatLab.RESULTS. It is proposed to study the methods of synthesis of digital models of compensation of voltage drops by the example of a study of an automatic reserve transfer system, demonstrating an approach to modeling this system. When developing models in the MatLab environment, the parameters of real technical elements and devices and their digital analogues are taken into account. The issue of creating a digital model of an electric drive system, including a model of an asynchronous motor with a short-circuited rotor, is considered. The result, after final refinement, can be used to design a real system in production conditions.CONCLUSIONS. The developed model of the automatic transfer switch system is operable, the time indicators are satisfactory for systems that do not make excessive demands on performances and time intervals. For systems that are sensitive to current inrushes during load transfer, some improvements are required, which are reduced to the implementation of a high-speed automatic switch system. The development of this system is currently at the research stage, namely, the compilation of a load transfer logic that takes into account the phase matching of electrical circuits.

Formal grammar methodology for digital visualization of Islamic geometric patterns

In the oriental practice of art and architecture, and among the regions under their influence, Islamic geometric patterns (IGPs) have been widely used, not only due to aesthetics and decoration but also to make it possible to cover wide flat surfaces, curved surface of domes, and perforated surfaces of window and partitions, with perfectly tessellated shapes. However, with advances in time and technology, these techniques could not connect to the new technologies and benefit from the capacities of digitalization. Recent progress in science and technology tends to open new doors to study geometrical patterns by digitalizing the old ones and developing new variations. This study looks at formal grammar and computer science to introduce a new approach to digital visualization of available IGPs, particularly, star patterns. We investigate the potentials of developing a re-writing system for simulation of IGPs to provide a flexible platform, which allows introducing IGP to CAD/CAM software without previous knowledge on their design or drawing techniques. This methodology allows designers to directly develop various scenarios of IGP applications and implement them on related CAD/CAM tools. Formal language and grammar theories, based on applied mathematics are contributing to the advancements of computer science and digital modeling. They can provide an opportunity to express relational definition and written equivalents of the geometries by using strings and symbols. It is supposed that by using the formal grammar frameworks, certain languages could be developed to visualize IGPs in a machine-friendly way, and consequently, this computational interpretation of IGPs facilitates their application and further developments, for example, regards to digital fabrication. The presented method of IGP visualization is developed as a C#-based add-on for Grasshopper in Rhino3D, one of the main modeling tools used by architects and product designers.

Size Effect on Mechanical Behaviors of Intact Rocks Based on Enlarged Digital Models

The size effect on mechanical behaviors of rock materials has been a challenging topic. The previous research is mainly to study the relationship between known large-scale models and representative element volumes. However, only limited scale models can be obtained in situ or laboratory in many cases, so tests or simulations of mechanical response behaviors of large-scale models cannot be carried out. In order to obtain large-scale models, this paper proposes a multi-scale enlarged digital modeling method to synthesize granite models based on texture self-similarity. The representational ability of synthetic granite is analyzed by using mathematical statistics and finite-difference numerical method. The results show that synthetic granite can characterize the natural rock well in terms of texture morphology, geometric characteristics, and mechanical behaviors. Then, the size effect on mechanical behaviors of intact granite is performed based on an enlarged digital model. The results show that the uniaxial compressive strength of intact granite increases with the increase of model size. In addition, the relationship between heterogeneity and homogeneity is established at different unit scales by using the synthetic digital granite model. The enlarged digital rock model has great potential in studying size effects with rock heterogeneity.

Analog and digital modeling of sound and impaired periodontal supporting tissues during mechanical testing

Periodontitis is one of the most common conditions affecting oral health among adults, posing a great challenge for both patients and also for dentists aiming to treat this disease. In severe stages such deterioration of the supporting tissues, namely the periodontal ligaments and the bone, can occur, which will affect the biomechanical behavior and therefore the longevity and survival of the affected teeth. In order to be able to plan both periodontal and subsequent restorative treatment properly, valid modelling of the current clinical situation is advised. The aim of the present article is to comprehensively discuss possible analog and digital modeling methods of periodontally affected teeth and the periodontal structures surrounding them. Modelling possibilities can serve later as the basis of mechanical load, digital finite element studies, and also aid clinical treatment planning.

Advantages of Implementing Virtual Reality Tools in Design and Technological Preparation of Production

Along with digital modeling, the key modern technologies include virtual (VR) and augmented (AR) reality, the use of which is a prerequisite for the implementation of the fourth industrial revolution, also known as Industry 4.0. However, at Russian enterprises, these tools have not become widespread yet. The paper analyzes the possibility of using the tools of virtual and augmented reality and introduces the available Russian instruments. Practical examples consider the application in this area of — one of them — the VRConcept system — in detail. The availability of support in the VRConcept system for the data presentation format of the domestic computer-aided design system Compass-3D simplifies its implementation and use at the enterprise.

ANALYSIS OF THE COMBINATION OF METHODS OF FASTENING THE JUNCTION POINT OF A HORIZONTAL TUNNEL WITH A VERTICAL SHAFT IN CONDITIONS OF DENSE URBAN DEVELOPMENT

Purpose. The problem of compares the long-term behavior of a tunnel-well taking into account the rigid and flexible couplings in the projected structures in Ukraine with 3d digital modeling using the three-dimensional finite element method. A refined geotechnical model has also been developed, taking into account the nature of the piezometric starting conditions and the proposed piezometric conditions for assessing the long-term condition as well as a summary of the properties and dimensions of the tunnel and the shaft. Methodology. Analysis of structural connections based on the experience of building shallow subways in dense urban development on the example of construction projects in China and Mexico. Search for the optimal combination of implemented methods to achieve the optimal result. Problems of a choice of a mode with 3d digital modeling using the three-dimensional finite element method based on two assumptions; the first assumption considers the rigid connection as a monolithic concrete structure between the shaft wall and the tunnel body, and the second assumption considers a material with elastic behavior between the two structures, which in turn leads to a flexible connection. The main parameters that must be clarified and corrected by the designer of the system during commissioning are determined. Next, the soft soil model was used to perform the analyzes with end elements for compressible layers. Findings. Simulation in the application, the Plaxis software environment obtained graphs of transients for the most important operating parameters, such as the geometry of the tunnel and the indicated lining, the flotation pool, three-dimensional clusters. Originality. Scientific interest in advancing technologies used in combination. Development of an algorithm for the optimal selection of the parameters of flexibility and durability in specific conditions, to save time and simplify the calculation forms. Practical value. The analysis of the obtained results is carried out, the main focus was on the relative loads and stress concentrations in the connecting elements, namely the stresses that occur in the transverse direction of the joint. Also in articles were determined some of the advantages and disadvantages of the different connection alternatives are discussed in order to neutralize the impact of the case in the future.

Contour Fitting of Fused Filaments Cross-Section Images by Lemniscates of Booth: Application to Viscous Sintering Kinetics Modeling

A method for image analysis was implemented to determine the edge pixels of two biopolymer-based thermoplastic filaments during their hot melt isothermal sintering at 120 °C. Successive inverted ellipses are adjusted to the contour of the sintered filaments and lead to the identification of the parameters of the corresponding lemniscates of Booth. The different steps of the morphological image analysis are detailed, from 8-bit coded acquired images (1 frame/s), to the final fitting of the optimized mathematical functions describing the evolution of the filaments envelope. The complete sequence is composed of an initial pure viscous sintering step during the first minute, followed by viscoelastic swelling combined with melt spreading for a longer time, and then the stabilization of the sintered filaments shape for over 2 min at high temperatures. Using a master curve obtained from Hopper’s abacus, the characteristic viscous sintering time is assessed at tvs = 78 s, confirming the one previously found based on the measurement of the bonding neck length alone. Then, the full description of the evolution of the thermoplastic filaments envelope is assessable by image analysis during sintering trials as a result of its digital modeling as successive lemniscates of Booth, reflecting geometry changes in the molten state.

Research on Digital Modeling and Life Cycle Information Management of Architectural Heritage Protection Based on BIM

Building information modelling (BIM) has been adopted in the architectural heritage industry. The digital protection method with BIM Technology as the core can introduce the information management workflow into the protection of architectural heritage, which can provide possibility for the complete preservation of all kinds of information related to the architectural heritage, improve the efficiency of protection, and meet the management needs of the whole life cycle of the architectural heritage. This paper is based on digital technology and combined with the characteristics of architectural heritage to create a BIM model of architectural heritage. The Autodesk Revit software, which is commonly used in China, is used as the entry point, and the C# language is used to develop Revit to make up for the shortcomings of traditional architectural heritage protection. At the same time, all kinds of information related to the architectural heritage are completely preserved, improving the efficiency of protection work, and meeting the information management needs in the process of building heritage maintenance and management.

Acute Approaches to the Development of Closed Cycle Economy in the Field of Hard Communal Waste Treatment

By methods of analysis and synthesis the article studies the problem of developing closed cycle economy in the field of hard communal waste treatment (HCW). Dynamics of waste making up was analyzed and its physical and mechanic properties and chemical composition were provided. The article gives economic tools, functions and classification of these tools that are necessary to organize the process approach to management. The authors put forward a promising scheme of treating HCW built on the basis of European experience and worked out the acute functional-structural scheme of the treatment system by the HCW complex, which demonstrates key business processes and tools of management. Such complex approach to describing the system of HCW treatment can simplify digital modeling of multi-variant business processes, such as burial of waste at waste-grounds, utilization at waste-burning plants, sorting and recycling at waste-recycling enterprises. Digital modeling with successful automated functional and cost analysis can give an opportunity to decrease uncertainty in the field of economic efficiency of managerial decision-making for rational HCW treatment and development of closed cycle economy in this sphere. A correct choice of approaches to the development of closed cycle economy in the field of HCW treatment can reduce the load on nature and support health of people.