ა(ა)იპ განათლებისა და მეცნიერების პროგრესი
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The International Scientific and Technical Conference "Problems of Engineering Sciences"
Yerevan University of International Relations named after A. Shirakatsi
Yerevan – Armenia
May 20-22, 2022
Edited by
Gela Kipiani
Board of the Universities and Partners
გამომცემლობა
ISSBN
Committees
Honorary Committee
International Scientific Committee
Organizing Committee
INVESTIGATION OF PROPERTIES AND PARAMETERS OF COMPOSITE PLASTICS ON THE BASIS OF THEORIES OF HEREDITY
Bidzina Abesadze
Georgian Aviation University, Tbilisi, Georgia
Presented methodology, describing the rheological properties (complexity and relaxation) of composite plastics based on theories of heredity. The method includes in itself all the deformed material of the stretched-deformed material at a given moment temporarily with the wound of the essential state with the help of impact functions. The final purpose is to determine the parameters of this function, which will characterize a given specific composite material.
Determination of parameter functions influences the analytical path is impossible because of the complex mathematical form, therefore the simplified method is used, including the combination of graphs, representation of the theoretical theory, and so on. At present, this method is used to assemble graphs with the help of modern computer programs. The result determines the specific parameters of the percussion functions, as well as the module of adjustment of materials and other characteristics. Semi-finished results allow you to accurately determine the geometric scale details in the case of using a specific material under the given conditions of assembly.
EVAPORATION - INFLUENCE OF CONDENSATION PROCESSES ON THE SUSTAINABILITY OF TORNADO-LIKE EVENTS
Amiran Aptsiauri, Gegi Aptsiauri
Georgian Aviation University, Tbilisi, Georgia
Amiranaptsiauri@gmail.com, Gegiaptsiauri@gmail.com
Thermodynamic analysis of complex, multicomponent systems confirms that alternating phase transformations can perform a thermodynamic cycle, that generates mechanical energy by converting the thermal energy of the environment. In particular, such a thing is possible when water droplets condense in the air at relatively low temperatures, which is accompanied by the cooling of the air, so when the condensation process takes place at higher temperatures, a thermodynamic cycle is carried out, in the process the gas absorbs heat and converts it into mechanical energy. In the upper, cloudy part of a tornado, when the blunt center of a rotating vane cone absorbs air, saturated with fog and droplets, the smallest droplets of fog evaporate due to the high velocity of the flow, thus completing a process accompanied by a simultaneous decrease in air temperature and entropy. In addition, the temperature drop is relatively insignificant, because the pressure increases as the flow move from top to bottom and the parallel compression of the air partially compensates for the temperature drop. Thus, this process is close to the isothermal process, where the entropy decreases and the pressure increases. Inside the tornado within the land surface, we have airflow saturated with moisture as much as possible, followed by intense rain and hail. The flow of rain and hail on the ground causes a torrent, while the marsh harrier changes direction with the ground, loses kinetic energy (resulting in a colossal collapse) and a relatively calm stream begins to move, first horizontally and then vertically. At low speeds, the air cannot hold a large amount of moisture and some of it condenses, causing rain near the tornado. This process is close to the isobaric process, in which entropy increases. Afterward, the condensed air is led upwards again. Completes the circuit, that triggers the release of energy and ensures, that the tornado is maintained for a long time. The fact, that tornadoes occur only in cloudy atmospheres, proves that phasic transformations play one of the main roles in this process.
THE LAWS OF THE MICRO PARTICLES AGAINST THE LAWS OF PHENOMENOLOGICAL THERMODYNAMICS
Amiran Aptsiauri
Kutaisi Technological Academy
The paper shows that the founders of modern thermodynamics, who, from the position of the second law, refuted the idea of the brilliant Scottish scientist James Maxwell about the possibility of sorting molecules, made a gross mistake, which determined the development of energetics and scientific and technological progress in general, in the wrong direction. Returning again to the idea of James Maxwell that, in order to obtain useful energy, it is possible to use the thermal energy of an equilibrium medium (a system of bodies of equal temperature), by sorting fast and slow molecules, the author of this work emphasized that the sorting of molecules actually occurs on the phase separating boundary surface at liquid evaporation. Therefore, evaporation is one example of such processes that violate the principles of Clausius, Kelvin and Carnot. It is proved that, in real complex systems in which there is a phase, chemical, mechanical, electromagnetic, etc. non-equilibrium, temperature equilibrium is not an obstacle to the generation of useful energy. Accordingly, the fundamental principles of thermodynamics are valid only for simple thermodynamic systems and for the correct development of science, in classical thermodynamics, the approach of James Maxwell must be brought to the fore.
It is shown that the validity of Carnot's theory implies the validity of Clausius's theory, and when proving Clausius's theory, the validity of Carnot's theory is implied. Accordingly, there is a movement of logical thought in a vicious circle. The discrepancy between theory and practice is confirmed by the existence of such physical processes that violate the requirements of the second law of thermodynamics. As such, the problem of air and warm water drop is given. The paper shows that the presence of chemical processes, by analogy with phase transformations, also leads to a violation of the second law of thermodynamics.
Accordingly, the time of James Maxwell should come in modern thermodynamics.
POSSIBLE THEMATIC INTERPRETATIONS OF DIFFERENT DIMENSIONAL MODELS IN ARCHITECTURAL-CONSTRUCTION DESIGN
Vakhtang Archvadze
Georgian Technical University, Tbilisi, Georgia
To some extent, design is associated with modeling. Therefore, the appropriateness of applying some of the prominent modeling theories in the course discussing design-specific methodological issues in various fields (including architectural-construction) should not give rise to any doubts or questions. In response to the possible (provoking) remark that “theory without practice is dead”, we may cite a well-known saying, whereby nothing is as practical as a good theory. The introduction to this article, tinged with somewhat deliberative tone, reflects the authors’ keen interest in the study of urban development objects and design issues amid the logical methodological boom and paradoxical historical zigzags. The following are the problem-specific issues:
• Design - as one of the crucial types of modeling
• Identifying spatial-temporal priorities in modeling
• Key features of modeling (model classification)
• Dimension – as a crucial characteristic of a model and its association with mathematical objects (structures)
• Generalizing the concept of dimension and the prospects of its use
• Geometric interpretation of “non-geometric” objects and processes
• Three main aspects of modeling (cognitive, creative, communicative)
• Thematic interpretations of dimensional modeling
• Paradox of a fractal dimension.
DETERMINATION OF SEISMIC INERTIAL LOADS OF AN ARCH DAM
Gocha Badzgaradze
Georgian Technical University, Tbilisi, Georgia
Arc dam calculations are performed separately for the three directions of the seismic wave: along the valley / longitudinally, transversely / across the valley and vertically. When designing a dam, the results of one of these three calculations that reach the maximum values of its internal tension are taken into account. Most often, this is the calculation of seismic impact on arched dams when the wave is directed transversely/beyond the valley.
It should be noticed that in the calculations of arch dams, which is based on the spectral theory of seismic resistance of buildings, the methods for determining the calculated inertial loads are still being refined. According to the earlier normative documents, this load was determined by summing its values, which corresponded to each shape of the building's own oscillation spectrum. However, there is significant resistance to this method: the specified components of seismic load, as well as the different forms of the natural oscillation of the dam, occur at different times and, therefore, we have no right to sum them.
Consequently, such a calculation obviously does not reflect the real picture of the process of formation of seismic inertial loads on buildings. Various proposals are known from the literature to eliminate the indicated resistance.
Recently, it has been recommended to use a correction-determination approach, according to which the seismic loads are defined, as the mean square value of the loads, corresponding to each spectrum of the dam oscillation shape.
This method has another drawback. When determining the average quadratic value of the seismic load, the possibility of the seismic load of different signs at the same point on the average surface of the dam is not taken into account.
LIABILITY OF FRAME-PANEL BUILDINGS BY STRETCHING REINFORCEMENT UNDER CONSTRUCTION CONDITIONS
Lia Balanchivadze, Nino Nakvetauri, Boris Beraia
Georgian Technical University, Tbilisi, Georgia
l.balanchivadze@gtu.ge; n.nakvetauri@gtu.ge
Deformations caused by pre-voltage drop in pre-tensioned frame-panel buildings were processed and investigated.Pre-tensioned reinforced concrete frame-panel buildings with so-called reinforcement under construction conditions, construction with the IMS system, began in the 80s of the last century in Georgia and not only here (Azerbaijan, Ukraine, Russia, Belarus and other republics), the construction of which was simultaneously stopped and the city was left with unfinished and abandoned buildings, where the population still continues to live.For the purposes of reliability and safety, the structures of frame-panel buildings were inspected to determine the condition of the materials and joints used as the creep-induced deformations in the armature can be disastrous for both the floor and the connecting nodes.
The investigated materials showed that the magnitude of the voltage drop across the pre-stressing fittings does not pose a risk to the inter-floor overlap because, compared to theoretical studies, it was found that the slab deformation is entirely within the values of construction norms.
The aim of the studies was also to study the deformations caused by the breakage of the pre-stressing reinforcement. As the results of the study proved, inadmissible deformation of roofing structures is possible only if all the pre-stressing fixtures in the cross section are interrupted at the same time, which is physically impossible.
Therefore, based on the analysis of the obtained results, we can conclude that unfinished and semi-abandoned frame-panel buildings meet the standards in terms of reliability by stretching the reinforcement under construction conditions and it is necessary to complete and further exploit them.
A NEW DESIGN OF THE DISC FOR FINISHING THE SURFACE OF MINERAL - STONE CLADDING
Karolina Bednarczyk, Paweł Rajczyk
Czestochowa University of Technology
karolina.bednarczyk.97@wp.pl , rajczyk.pawel@wip.pcz.pl
The constructions of working elements of working tools, known from practice, in the form of discs for finishing grinding and polishing the surface of mineral materials, granites, and marble have many negative features. These include the irrational use of expensive materials introduced into the synthetic matrix of abrasive elements, for example (diamond powders) for the production of working segments. This is due to the analysis of technological operations, especially their work in the process of wall impact. The abrasive work efficiency is derived from the hardness of the segment matrix binder and the associated resulting ability to retain the diamond grain in the segment matrix.
The geometric form of the segments and their arrangement on the base surface of the wheel have a significant impact on the abrasive efficiency. Abrasive efficiency determined for tools in the form of a disc with a diameter of 100 mm rotating at a rotational speed of up to 660 rpm and moving with a translational motion Vp = 0.01 m/s can be defined as the length of the contact lines of the grains protruding from the surface of all abrasive segments arranged on the base face of the target. The presented dependencies allow to collect data in an organized form for the analysis of the work of newly designed material and geometric forms of the shield structure, where additionally the possibility of shaping the channels on the working surface of the disc for discharging the excavated material and the coolant supplied to the contact zone of the tool with the processed material in the process of surface treatment of mineral materials is taken into account.
STRUCTURAL TOPOLOGY OPTIMIZATION OF HIGH-RISE BUILDINGS CONSIDERING WIND AND GRAVITY LOADS1
Vasili Beruashvili
Georgian Technical University, Tbilisi, Georgia
Kutaisi International University, Kutaisi Georgia
Topology optimization has recently been investigated as a technique for the conceptual design of efficient structures during the early stage of the design of buildings to tackle the design challenges. The use of this technique, which leads to optimum structures, mostly results in aesthetic, lightweight, and best performance from the perspective of engineers or architects. However, the topology optimization results are not usually known for direct realization in practice, and the engineer and architect should be able to choose the best solution among numerous choices in close cooperation. This paper has focused on defining a parametric framework of continuous optimum design of lateral bracing systems for tall buildings considering wind and gravity loads. The bidirectional evolutionary structural optimization method was employed, considering the main optimization parameter, loading scenarios, and constraints. In order to show the effectiveness of the suggested topology optimization framework for minimizing compliance (maximizing stiffness) and minimum consumption of materials in the design of lateral bracing systems, 2D and 3D systems have been discussed. According to the obtained results, this framework could employ topology optimization during the conceptual design to seek a new definition of the optimum layout of lateral bracing systems with high structural performance, elegant geometries, and other characteristics considered by architects and engineers.
1This research PHDF-21-3812 has been supported by Shota Rustaveli National Science Foundation of Georgia (SRNSFG)
SLAB FOUNDATION REPORT BASED ON GROUND GEOTECHNICAL ALGORITHM1
Zurab Bobokhidze
Georgian Technical University, Tbilisi, Georgia
Monolithic or prefabricated foundations, which are mainly used for building columns in industrial construction, with well-known advantages, are characterized by high labor intensity of the construction site and significant cost of materials. Compared to monolithic foundations, the use of concrete stepped foundations, although it leads to some reduction in labor costs at the construction site, but at the same time significantly increases the cost of the materials used (carpet, steel), thereby increasing its cost.
One of the possible ways to increase the bearing capacity of building columns, tanks, radio-television and water towers, chimneys and ventilation pipes and other buildings of a circular capacity is the use of thin-walled spatial foundations of a conical or angular shape. At present, the manufacture of cone foundations based on tiles and industrial buildings laid under columns has been mastered by reinforced concrete plants in many countries.
The results of research in the field of cortical foundations have not yet met the requirements of practice. From a theoretical point of view, the issues of calculating such foundations under any loads, which have the shape of a conical membrane and are based on tiles and soil, will be especially poorly worked out.
The solution of such problems is associated with the need to take into account reports obtained using the geological properties of the soil, geotechnical analysis and computer programs. Also, an objective analysis of the load on the structure, when th
13 Br. Zubalashvili II dead lock