Browsing by Author "Okorokov, Andrii M."

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Assessing the Efficiency of Centralized Use of Train Formations within an Extensive Supply Network for Metallurgical Production
(TECHNOLOGY CENTER PC, Kharkiv, 2025) Zaruba, Oleksandr V.; Okorokov, Andrii M.; Vernyhora, Roman V.; Prokopa, Oleh I.; Khomenko, Yurii L.
ENG: This study investigates a transportation-technological system that enables raw material supply by rail to meet the needs of a metallurgical enterprise. The task addressed is to assess the effectiveness of centralized use of train shipments in an extensive supply network for the needs of metallurgical production. The hypothesis of the study assumes that under conditions of centralized management of the rolling stock fleet of railroad transport within an extensive supply network, its number will be smaller than in the case of a non-centralized one. A mathematical and simulation model has been built in the AnyLogic University Researcher environment using agent and discrete-event approaches. The main criterion is the minimization of the average delivery time; additional criteria are the optimal use of the working fleet of railroad cars and train locomotives. Applying them in combination makes it possible to optimize the working fleet of railroad cars and locomotives, taking into account the extensiveness of the supply network and the conditions of centralized management. It was experimentally established that with centralized fleet management, fluctuations and volumes of metallurgical raw material residues at the enterprise depend on the loading rate of railroad cars of the sending or group of railroad cars of the stepped routes. According to the calculated values of the determination coefficients, the approximation by the exponential function turned out to be denser. The variability of raw material residues decreases with a change in the technical loading rate of the train or railroad car batch. It was established that the difference between the standard deviation for the train loading rate of 4000 t (σ(х) = 4524.7 t) and the standard deviation of 2606.5 t (σ(х) = 4524.7 t) is 1918.2 t. This corresponds to 42% of the initial value of the indicator. The proposed approach allows for a more accurate assessment of the need for a working fleet of railroad cars and locomotives, as well as improves the efficiency of transportation management.
Determining Loading Patterns in the Bearing Structure of a Railroad Flatcar with a Floor Made from Sandwich Panels
(PC TECHNOLOGY CENTER, 2023) Lovska, Alyona O.; Nerubatskyi, Volodymyr; Okorokov, Andrii M.; Vernyhora, Roman V.; Zhuravel, Iryna L.
ENG: The object of research is the processes of emergence, perception, and redistribution of loads in the supporting structure of a flatcar with a floor made of sandwich panels. To reduce the impact of dynamic loads on the supporting structure of a flatcar, as well as the safety of goods transported in it, it is proposed to manufacture floors from sandwich panels. Within the framework of the study, mathematical modeling of the dynamic load on a flatcar when it runs in a loaded state was carried out. It was found that, taking into account the proposed solution, the accelerations acting on the supporting structure of a flatcar are reduced by 8.4 % compared to the typical one. At the same time, accelerations acting on cargo placed on a flatbed car are reduced by 11.7 %. The results of calculating the strength of sandwich panels, when arranged on a flatcar, proved the feasibility of the proposed improvement. The main indicators of dynamics of the improved flatcar structure operated in an empty state were determined. It was established that the flatcar movement is assessed as "good". A feature of the results reported here is that the improved supporting structure of a flatcar contributes not only to reducing its dynamic load but also to improving the safety of transported cargoes. The scope of practical application of the results is the engineering industry, in particular, railroad transport. The condition for the practical application of the research results is the use of energy-absorbing material in the structure of sandwich panels. The study could contribute to devising recommendations regarding the design of modern structures of railroad vehicles and increasing the efficiency of the functioning of the transportation industry.
Determining the Load on the Bearing Structure of a Flat Wagon for Long Cargo in Rail-Ferry Transportation
(TECHNOLOGY CENTER PC, Kharkiv, 2025) Lovska, Alyona O.; Okorokov, Andrii M.; Muradian, Arsen O.; Romakh, Valentyna L.; Bolvanovska, Tetiana V.
ENG: This study's object is the processes of perception and redistribution of loads in the supporting structure of a flat wagon for long-length cargo during rail-ferry transportation. The task addressed is to adapt a universal flat wagon for transporting long-length cargo. In this case, it is proposed to improve the structure of a flat wagon by equipping it with frame-type side walls reinforced with sandwich panels. The proposed technical advancement was substantiated by mathematical modeling of the dynamic loading of the flat wagon during transportation by rail ferry. The calculation results established that the proposed improvement contributes to a reduction in the dynamic loading of a flat wagon's supporting structure by 15% compared to the typical structure. The findings were confirmed by computer simulation. The results of calculating the strength of a flat wagon's supporting structure established that its strength is ensured. A special feature of the technical advancement is that it does not require intervening in the basic concept of a flat wagon's supporting structure since the side walls are removable. The scope of practical application of the research results is railroad transport. The practical use of the findings is subject to the absence of a natural degree of freedom of the side wall frame. The results of this study will contribute to improving the efficiency of railroad transport operation, including international traffic. The results could also prove useful for designing modern car structures with improved technical and operational characteristics.
Determining the Vertical Load on a Container with a Floor Made of Sandwich Panels Transported by a Flat Wagon
(TECHNOLOGY CENTER PC, Kharkiv, 2024) Lovska, Alyona O.; Stanovska, Iraida; Kyryllova, Valeriia; Okorokov, Andrii M.; Vernihora, Roman V.
ENG: The object of this study is the processes of perception and redistribution of vertical loads in the structure of a container with a floor made of sandwich panels under operational modes. To ensure the strength of the container, as well as the safety of the cargo transported in it, it is proposed to design a floor based on sandwich panels. It is assumed that each of these panels is made of two metal sheets in a layer between which an energy-absorbing material is placed. Given the presence of energy-absorbing material in the structure of the sandwich panel, the vertical dynamic loads acting on the cargo container during its transportation will be reduced. To substantiate the proposed solution, mathematical modeling of the vertical load on the container during its transportation by a flat wagon was carried out. It is found that the accelerations acting on the container of the improved design are 5.7 % lower than those acting on the container of standard design. The calculation of the strength of the container was carried out under operational schemes of its loads. It has been established that the strength of the container is ensured. A special feature of the results is that the reduction of the load on the container is achieved not by strengthening its structure but by introducing flexible connections into it. The field of practical application of the results is railroad transport. The conditions for the practical use of the findings are the use of energy-absorbing material in the structure of sandwich panels that form the floor of the container. The results of the research will contribute to improving the strength of containers under operating conditions, the safety of the cargo transported in them, as well as increasing the efficiency of the functioning of container transportation.
Development of a Simulation Model of Grain Delivery in Global Supply Chains
(National University of Life and Environmental Scienсes of Ukraine, Kyiv, 2024) Khomenko, Yurii; Matsiuk, Viacheslav; Okorokov, Andrii M.; Gorobchenko, Oleksandr
ENG: The main export shipments of grain to Ukraine are carried out through commercial seaports of the Black Sea, while the complex and multiphase transportation process creates delays and leads to additional costs at the points of connection of various types of transport. The purpose of the study was the process of transporting grain cargo for export through commercial seaports. Ukraine is a developed agricultural country that produces a significant share of the world’s grain volume, most of which is exported. The optimisation simulation model of multimodal grain cargo transportation developed in the study, in contrast to the existing ones, is a multiphase process with many initial parameters, subsystems, and technological elements that adequately reflect all components of the technological process of organising transportation by road, rail, and sea, and helps to optimise these processes. The model consists of several transport and technological subsystems, each of which corresponds to the process of grain transportation by road, rail, or water. The minimum total duration of cargo transportation from the place of origin to the moment of sending grain cargo for export by sea was chosen as the optimal criterion. To establish the minimum required number of replications and the minimum required model time, a series of experiments were performed, where the key and systematic modelling measurement parameter is the total time of grain delivery by land, from the point of origin to the sea trade terminal. As a result of modelling, the optimal number of rolling stock of different types of transport and the transportation time for each phase of the process were determined. Logistics operators of the agro-industrial sector can apply the model to improve grain delivery routes and schemes, evaluate and improve technological parameters, and minimise transportation time and costs.
Experimental Studies on the Strength of a Flatcar during Shunting Impacts
(MDPI, Basel, Switzerland, 2023) Vatulia, Glib; Gerlici, Juraj; Lovska, Alyona O.; Fomin, Oleksij V.; Okorokov, Andrii M.; Pavliuchenkov, Mykhailo; Petrenko, Dmytro; Kravchenko, Oleksandr
ENG: The increasing demand for container transportation makes it necessary to equip the wagon fleet with appropriate flatcars in good technical condition. The study deals with the determination of the strength of the flatcar during shunting impacts using the finite element method. The flatcar model 13-401 modernized with fixed fittings for securing containers on the frame was used as a prototype. The authors determined the fields of the maximum equivalent stresses in the bearing structure of a flatcar. The strength calculation was made in SolidWorks Simulation. It was found that, during a shunting collision, the maximum equivalent stresses to the flatcar were about 418 MPa and they were concentrated in the fixed fittings. The strength was also studied using the method of electric strain gauging. The research included different impact speeds. The test results showed that the maximum difference between the stresses obtained theoretically and experimentally was 17.0%. The strength model of the flatcar was tested using the Fisher criterion. The study demonstrated that the damage to the bearing structure of the flatcar and containers could be reduced when applying an improved interaction diagram.
Revealing the Causes of Delays at Transit Points along an Intermodal Grain Supply Chain
(TECHNOLOGY CENTER PC, Kharkiv, 2025) Khomenko, Yurii L.; Okorokov, Andrii M.; Matsiuk, Viacheslav I.; Zhuravel, Iryna L.; Pavlenko, Olena I.
ENG: This study’s object is the transport and technological system of grain supply along international routes. The issue considered is the emergence of excess cargo weight at the junctions of various types of transport. The study was conducted on the basis of a constructed simulation model built according to the agent and discrete-event principles. It covers both the maximum transportation volumes in one of the Ukraine’s oblasts in 2021 (880 thousand tons) and the forecasted indicators (1–1.5 million tons per year). The application of the model has made it possible to determine the optimal parameters for the fleet of vehicles in a supply chain, guided by the system criterion – minimization of the average delivery time of one ton of grain. It was established that for transporting 1 million tons of grain per year, the optimal composition of the transport fleet should include 92 trucks and four railroad routes. Patterns in the formation of excess cargo weight depending on the estimated composition of vehicles were also determined. With a planned transportation intensity of 1 million tons per year, reducing the number of trucks by 12 units could lead to the accumulation of 237 thousand tons of cargo mass at transit points. Reducing the number of railroad routes by one unit would lead to the accumulation of 544 thousand tons of cargo mass, which corresponds to USD 106 million. The proposed model makes it possible to assess the consequences of delays in delivery, as well as the formation of excess cargo mass at transit logistics terminals and grain elevators.
Substantiating the Reliability Conditions for the Production Process at Metallurgical Enterprises Through the Fault-Tolerant Functioning of the System «Extraction of Raw Materials – Technological Railroad Routes – Metallurgical Production»
(PC TECHNOLOGY CENTER, 2024) Zaruba, Oleksandr V.; Okorokov, Andrii M.; Vernyhora, Roman V. ; Zhuravel, Irina L.; Barkalova, Nataliia O.
ENG: The object of this study is the process of formation of insurance reserves at enterprises in the metallurgical industry. Under conditions of uneven supply of raw materials to metallurgical enterprises due to disruption of the transportation process or other reasons, there is a need to create insurance stocks in order to ensure the continuity of production. At the same time, it is necessary to take into account existing restrictions, such as the limited capacity of railroad sections and the impossibility of organizing parallel movement of trains, etc. The presence of these limitations makes it impossible to use classical methods for solving similar problems, such as linear programming. Therefore, to resolve the task, a simulation model was built, based on the discrete-event principle in the AnyLogic University Researcher environment using Oracle libraries and the Java SE compiler. With the help of the model, the process of rotation of dispatch routes at the railroad yard with multiple suppliers and one consignee was formalized. The optimization criterion was chosen to be the minimum deviations of fluctuations in reserves of iron ore concentrate and coke. Analysis of the simulation results revealed that the optimal size of the fleet of railroad routes on the selected rotation polygon is 30 units; at the same time, their utilization rate will be 65 %. It was also established that fluctuations in raw material stocks have a «natural character», which is confirmed by the normal distribution of the density of stock volumes. Under these conditions, the value of fluctuations in the volumes of the main raw materials will be ±13115 t/day for iron ore concentrate, and ±5298 t/day for coke. Reducing the range of fluctuation of raw materials volumes could make it possible to optimize the costs of creating stocks and streamline the transport work of the enterprise for providing raw materials.