ADVANCES IN MECHANICAL ENGINEERING AND TRANSPORT
Advances in Mechanical Engineering and Transport is a peer-reviewed, open access journal that publishes original research articles as well as review articles in all areas of mechanical engineering, fundamentals of the transport system, technology for carrying passengers and freight, technology for multimodal transportation and logistics, agricultural motor vehicles, traffic safety and environment protection, design, manufacture and exploitation of motor vehicles, transport energetics, fuels, lubricants and maintenance materials, transport information technologies, transport economics and management, transport educology, and also, in areas of mathematical modelling and simulation of technical processes. The journal is intended for practising engineers, academic and industrial researchers.
ЛУЦЬКИЙ НАЦІОНАЛЬНИЙ ТЕХНІЧНИЙ УНІВЕРСИТЕТ
RESEARCH OF TEMPERATURE PROCESSES DURING DRILLING OF HOLES
The paper addresses an axisymmetric thermophysical problem occurring during deep-hole drilling, based on a proposed mathematical model for temperature calculation using the heat source method and the principles of spatial-temporal correspondence and local influence. The dependencies of the thermal process were determined, taking into account the mutual positioning of the cutting tool and the part, the material of the workpiece, the presence of cooling with cutting fluid, cutting conditions, chip removal, and the duration of the drilling operation itself. This is particularly important for deep drilling, where the heat source is continuously displaced. It was established that the calculation of the temperature field in the workpiece depends on the action of a ring-shaped heat source with a uniform heat release intensity distribution. Theoretical analysis showed that the maximum temperature should not exceed 300 °C (without lubricating and cooling fluid) and 180 °C (with lubricating and cooling fluid), respectively. Standard chromel-alumel thermocouples (temperature range −100 °C to +1000 °C) were used for temperature measurement. Deep-hole drilling experiments were performed on parts made of Steel 45 (analogous to C45E and Ck45 according to the EU standard EN 10083-2) with diameters of 10 mm and 20 mm, using special deep-drilling tools. The machining was carried out on a universal lathe model 16K20, modified for deep drilling. The temperature in the tool-workpiece contact zone and the temperature distribution within the workpiece (temperature gradient) were calculated. The adequacy of the proposed mathematical model was confirmed, as the calculated temperature values corresponded well with the experimental data. Keywords: heat source, deep drilling, thermal conductivity, heat source method, principle of spatial-temporal correspondence.
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Influence of fuel type on the fuel economy and environmental performance of an automotive engine
Road transport is among the largest consumers of petroleum-based fuels and one of the main contributors to environmental pollution. Therefore, research focused on expanding the fuel base for vehicles and promoting the efficient use of alternative fuels is of significant importance. Currently, in Ukraine, the most widespread alternative fuels are alcohol–gasoline blends containing up to 50% bioethanol by volume, as well as liquefied petroleum gas (LPG). A key advantage of these fuels is that they can be utilized in internal combustion engines without major structural modifications. This paper presents the results of an experimental investigation into the fuel economy and environmental performance of an automotive engine operating on conventional gasoline A-95 and alternative fuels such as alcohol–gasoline blend E40 and liquefied petroleum gas. The results indicate that when operating on E40, the engine demonstrates an average increase of 12% in hourly mass and specific effective fuel consumption. The volumetric fuel consumption rises by approximately 8.5%. In terms of exhaust emissions, the concentration of unburned hydrocarbons (CmHn) decreases by an average of 10.4%, while nitrogen oxides (NOx) concentrations are reduced by about 3.5%. When operating on LPG, both hourly mass and specific effective fuel consumption decrease, with an average reduction of 16.35%. However, the volumetric fuel consumption increases by approximately 12%. The concentration of unburned hydrocarbons (CmHn) in the exhaust gases rises by an average of 36% compared to gasoline A-95 operation, whereas NOx emissions are reduced by about 11.6%. Keywords: fuel economy, environmental performance, alternative fuels, alcohol–gasoline blend, liquefied petroleum gas.
Modelling trip generation for road freight transportation in Kryvyi Rih
The paper proposes a method for modelling demand generation (number of trips) in road freight transport within a four-stage demand model. This methodology is structured as follows: 1) urban freight transport is categorized into three distinct systems: light trucks (2.0 to 2.6 m in length, with two or more axles and a maximum carrying capacity of 2 t), medium three-axle trucks (over 2.6 m in length, with a carrying capacity ranging from 2 to 8 t), and three-axle dump trucks (with a carrying capacity exceeding 8 t). 2) In the procedures for trip generation and attraction, the number of jobs within transport districts is employed as a key structural indicator, which is then distributed according to the specific set of economic activities relevant to each freight transport system. To validate the proposed approach, a modelling of demand generation for freight transport in the transport model of Kryvyi Rih was conducted using the PTV Visum software. The results of the modeling demonstrated that the number of trips generated and attracted by different zones of the city matched, confirming the accuracy of the chosen method for calculating the trip generation for specific freight transport systems. It has been established that the production and attraction of trips by urban freight transport in Kryvyi Rih in the six zones where enterprises of the mining and metallurgical complex are situated is notably higher than in other zones within the model. These zones, referred to as mining areas in previous studies on urban mobility in Kryvyi Rih (specifically concerning passenger transport), exhibit distinct patterns in freight transport demand. Future research will focus on further procedures for calculating transport demand within the four-stage transport model. Keywords: transport demand, road freight transport, transport system, transport modelling, PTV Visum, demand generation, trip production, trip attraction, zone, mining area.
Existing methods are analyzed and the results of experimental studies on determining the cornering stiffness on an undeformed support surface are presented. When studying the cornering stiffness, the tire is considered as a component of an complex mechanism, which is an elastic wheel. At the same time, a distinction is made between the movement of the wheel along a curvilinear trajectory and the plane-parallel movement with slip. During the movement of the wheel along a curvilinear trajectory, the disk is simultaneously displaced laterally and twisted relative to the tire contact patch, which causes a lateral force and a twisting moment relative to the vertical axis. The plane-parallel movement of the wheel with slip causes a lateral displacement of the disk relative to the tire contact patch, which causes a lateral force that is displaced relative to the center of the tire contact patch. Both the movement along a curvilinear trajectory and the plane-parallel movement with slip are associated with a lateral force that depends on the cornering stiffness. It is proposed to experimentally determine the cornering stiffness of truck tires, using the truck as a tester. Analytical dependencies are presented that functionally link the cornering stiffness, lateral stiffness of the tire, angular stiffness relative to the vertical axis and the longitudinal axis of the contact patch. These dependencies allow determining cornering stiffness by the indirect method. The results of experimental and calculated data of the cornering stiffness for a tire size 1300x530-533 mod. VID-201, which is installed on all-wheel drive KrAZ truck, are presented. The results of the research may be useful to specialists working on improving the handling and stability of vehicles. Key words: cornering stiffness, slip angle, lateral stiffness, tire contact patch, methodology, undeformed support surface.
The possibility of using telematics for monitoring the technical condition of vehicles
With the development of electronic equipment in cars, the role of telematics in the automotive industry is steadily growing. According to various estimates, most of the innovations in the industry are related to electronics. Increased safety in motor transport is achieved thanks to driver assistance systems (ADAS) - processing of vision data, radar, visualization and sensors, as well as adaptive lighting systems, display and monitoring technologies for the user. Environmental friendliness is ensured by engine control systems, highly efficient intelligent power electronics. Vehicles are equipped with systems for determining position on the ground and exchanging information. The concept of connected vehicles is being developed, which constantly provide information about themselves and receive information about the surrounding environment. Today, automakers equip all important vehicle components with control sensors, as a result of which a data flow is formed about the operation of key vehicle systems. Telematics represents a combination of technologies for collecting and transmitting information from the vehicle. It integrates GPS tracking, on-board diagnostics, sensor technologies and wireless communication systems into a single vehicle and driver management system. Telematics optimizes operational activities through dynamic route planning, driver behavior monitoring and fuel efficiency management. To solve the problem of predictive maintenance and improve the life cycle of vehicles, it is necessary to choose an effective method of remote communication. The selected technology must meet the requirements for information transmission range, speed and security of data transmission. The transmitted information must be processed in a timely manner and be meaningful for making management decisions by the management of transport companies. Keywords: telematics, telematics system, diagnostic parameters, on-board diagnostics, intelligent transport systems, wireless communication, technical condition prediction.
Analysis of the Braking Process of a Vehicle with an O2-Category Trailer
The paper considers the emergency braking of a vehicle combination consisting of a towing vehicle and an O2-category trailer with regard to directional stability. It is shown that the widely used constant distribution of the total braking force between the axles of the road train does not ensure braking efficiency and may cause premature wheel lock on individual axles. The object is the vehicle–trailer road train in braking mode; the aim is to develop a planar mathematical model for determining normal reactions on the wheels, forces in the coupling and the conditions for simultaneous approach of all wheels to the lock limit. The model is based on equilibrium equations of forces and moments for the towing vehicle and the trailer, taking into account braking-force distribution coefficients, coordinates of centers of mass, dynamic tyre radii and the height of the coupling point. Analytical expressions are derived for normal reactions on all axles and for vertical and horizontal reactions in the coupling, which makes it possible to evaluate redistribution of axle loads during deceleration. It has been established that the braking force acting on the trailer axles causes a more intensive change of reactions on the wheels of the rear axle of the towing vehicle than on the front axle, which reduces the adhesion coefficient at which the rear wheels lock. Conditions for simultaneous attainment of the lock limit by all wheels of the combination have been obtained, as well as the optimum share of the total braking force that should be assigned to the trailer axles. The proposed model can be used when choosing mass and braking-system parameters of vehicles with O2-category trailers to ensure stable and efficient braking without anti-lock systems. Keywords: vehicle combination; towing vehicle; O2-category trailer; emergency braking; distribution of braking forces; normal reactions; coupling device; adhesion coefficient; wheel lock; mathematical model.
Tendencies in the development of the automotive industry under digitalization conditions
The automotive industry is currently undergoing a profound transformation driven by digitalization, which has become a key factor determining its competitiveness and sustainability. This research aims to identify the main trends, challenges, and opportunities related to the digital transformation of the global and Ukrainian automotive sectors. The study is based on a comprehensive analysis of scientific literature, industrial reports, and global best practices concerning the implementation of digital technologies in vehicle design, manufacturing, and operation. The results demonstrate that digitalization influences all stages of the vehicle life cycle – from conceptual design and production to maintenance and utilization. The most significant technological trends include vehicle electrification, the development of autonomous and connected systems, the integration of Internet of Things (IoT) and Big Data technologies, and the use of digital twins for predictive diagnostics and virtual testing. The research also emphasizes the growing importance of over-the-air (OTA) updates, remote monitoring, and cloud-based platforms that transform traditional models of vehicle ownership and maintenance. Another key trend is the emergence of new business models such as Mobility as a Service (MaaS), which shifts the focus from vehicle ownership to access to mobility services through digital platforms. These changes stimulate the evolution of smart transport ecosystems and encourage interdisciplinary collaboration between the automotive, IT, and energy sectors. The article highlights that while developed countries are rapidly advancing toward fully digitalized transport systems, countries like Ukraine face certain barriers, including outdated production infrastructure and insufficient investment. However, the growing digital competence, engineering potential, and integration into European innovation networks create favorable conditions for accelerating digital transformation in Ukraine’s automotive industry. Keywords: automotive industry, digitalization, Industry 4.0, electric vehicles, autonomous transport, Internet of Things (IoT), Big Data, digital twin, Mobility as a Service (MaaS), smart mobility.
Spare Parts Inventory Management in Freight Transport Logistics under Multifactor Uncertainty
This article investigates approaches to adaptive spare parts inventory management in the context of freight transport logistics under conditions of multifactor uncertainty. The study accounts for the influence of variable vehicle loads, seasonal demand fluctuations, fleet technical condition, and risks of disruption in logistics processes. The use of digital technologies – particularly telematics systems, GPS monitoring, and Internet of Things (IoT) solutions – is substantiated for collecting and analysing operational data. This enables the formation of dynamic wear profiles and highly accurate forecasting of spare parts demand. A conceptual adaptive inventory management model is proposed, integrating scenario modelling, empirical coefficients, and predictive algorithms based on real-world freight transport data. The developed model enables timely responses to changes in vehicle utilisation intensity, optimises inventory levels, reduces storage costs, and minimises downtime risks. A comparative analysis of traditional and adaptive inventory strategies confirms the advantages of flexible approaches in unstable environments. The research findings can be applied to improve fleet maintenance efficiency, enhance logistics planning, and support the implementation of digital solutions in inventory management systems. The proposed models offer practical value for transport companies seeking to improve delivery reliability, reduce costs, and adapt to contemporary market challenges. Key words: adaptive inventory management, spare parts, freight transport, telematics, Internet of Things (IoT), maintenance, digital logistics.
Strategies for managing road transportation in the context of global market changes: analysis of the activities of logistics operators
The article addresses the strategic management of road freight transportation in the context of global market transformations, digitalization, and increasing environmental requirements. The research is driven by the need for logistics operators to develop adaptive management strategies that ensure competitiveness and operational efficiency in a rapidly changing external environment. The study aims to develop theoretical and methodological foundations and practical recommendations for forming effective road freight management strategies based on a comprehensive analysis of logistics operators' activities. The methodological basis of the research includes a systematic analysis of scientific sources, expert surveys involving industry specialists, statistical modeling, and performance data analysis from logistics companies. The conceptual model of strategy formation developed by the authors reflects the cyclical interrelationship between environmental analysis, strategic choice, implementation, and performance evaluation. Key research results include the identification and ranking of global factors impacting logistics operators' activities. According to expert assessments, fuel price fluctuations (9.2/10 points) and environmental requirements (8.7/10 points) have the most significant impact. The authors have developed a classification matrix of management strategies based on two key parameters: innovation level and operational efficiency. This matrix identifies four strategic positions: Market Leaders, Innovative Developments, Efficient Traditionalists, and Outsiders. A quantitative assessment of the impact of strategic directions on operational performance indicators was conducted. The research demonstrates that AI-powered route optimization reduces transportation costs by 10-15% and improves delivery reliability by 5-7%. The implementation of digital freight platforms decreases costs by 5-10%, while blockchain-based document automation reduces costs by 3-5% and improves operational reliability by 4-6%. The author has improved the methodological tools for assessing the digital maturity of transport companies and proposed a mechanism for continuous adjustment of strategies based on performance monitoring. The practical significance of the results is that they enable logistics operators to objectively assess their current strategic position, prioritize technology investments based on quantitative impact assessments, and develop adaptive strategies resilient to global market changes. The implemented measures allow for reducing operational costs, improving service quality, and strengthening competitiveness in international markets. The conclusions confirm the effectiveness of the integrated approach to road freight management, which combines technological innovations with operational optimization. The proposed models and methodologies can be used by logistics operators to enhance competitiveness under globalization and by government agencies when developing transport infrastructure development programs. Keywords: road freight management, logistics operators activity analysis, international transport logistics, strategic management, digital transformation, operational efficiency of transport processes, adaptive strategies, technological innovations.
Mathematical models for calculating toxic emissions of a bus with a diesel engine
An integral part of the general problem associated with improving the design of manufactured cars, maintaining them in working condition, the quality of fuel, lubricants and their economy, improving the road network and organizing the movement of transport vehicles, is their toxicity. Many researchers have been working on issues of saving fuel and energy resources and reducing engine toxicity, and currently there are a significant number of relevant recommendations. However, simple and fairly effective proposals have yet to be developed. The task of optimizing the operation of passenger vehicles, taking into account environmental safety, is one of the components of human regulatory activity aimed at improving the urban environment. Thus, reducing harmful emissions from car engines is the most important public and social problem. When solving this problem, the preferred directions are those whose implementation is accompanied by savings in fuel and other material and technical resources. Known technical solutions for reducing harmful substances in engine exhaust gases are usually associated with changing their designs (this requires significant costs) or using expensive auxiliary devices to neutralize harmful substances (their installation on a car is often accompanied by a deterioration in engine efficiency). In this regard, it is advisable to primarily influence those factors that allow reducing harmful emissions from vehicles (and, accordingly, fuel consumption) during transport work. The article develops mathematical models for calculating toxic emissions from buses with diesel engines. The results of a machine experiment on calculating harmful emissions using the example of a Mercedes-Benz O530/Citaro C2 bus are also analyzed. One of the directions for increasing the fuel efficiency and environmental safety of buses is the practical use of rational driving modes. This allows us to consider the article aimed at increasing the efficiency of technical operation of cars by saving fuel and reducing toxicity as relevant. Keywords: bus, operating conditions, harmful emissions, environmental safety, mathematical models, speed.
Economic Efficiency of Centralized Maintenance and Servicing of Technological Vehicles in Iron Ore Quarries
The study substantiates and formalizes the criterion for determining the optimal level of centralization in performing routine maintenance and technical servicing of technological vehicles at iron ore quarries. The forms of functional relationships were established, and analytical dependencies were obtained between the costs of maintenance and repair of quarry dump trucks. The relationship between machine reliability and operating time necessary to meet the technological transport plan for ore was determined for cases where such repairs are performed in-house or through company-based or service maintenance at specialized enterprises using industrial methods. This approach allows determining the level of industry-wide centralization of maintenance and repair work for quarry vehicles, which enables minimizing specific operational costs per unit of transport work. To solve the tasks set, methods of techno-economic, correlation-regression, factor, and situational analysis were used (for studying the organization of dump truck repairs at mining enterprises or in the network of service centers); the methodology of optimal management, which ensures the economic-mathematical formalization of the components of the model for determining the level of industry centralization of technological vehicle repairs according to operating conditions; and the method of comparative economic analysis (for assessing the economic efficiency of the proposed model for reallocating funds allocated to restore the operability of quarry dump trucks). The optimal level of centralization of maintenance and repairs of 130-ton quarry dump trucks for ore transportation at iron ore quarries was calculated, and the feasibility of ensuring their planned operating time in technological transportation was substantiated. Keywords: transport system of an iron ore quarry, repair costs, in-house repairs, repairs by specialized organizations, statistical methods of control and management.
Experimental estimation of the impact of advance time on the efficiency of a coordination plan
The article examines the pressing issue of enhancing the efficiency of coordinated urban traffic control systems through the consideration of advance time required for the acceleration of additional vehicles accumulating in front of the stop line at successive intersections in a coordination plan. In contrast to foreign practices of implementing adaptive traffic control systems, under Ukrainian conditions, financial and infrastructural constraints dictate that coordinated signal control (green wave) remains the primary instrument for effective traffic control in cities. Existing methods for designing coordination plans do not account for the influence of additional vehicles emerging from secondary approaches to coordinated intersections, nor the time required for queues to accelerate to the speed of the main traffic flow. This reduces the overall efficiency of coordination and makes it impossible to ensure the smooth flow of vehicles along coordinated arterials. The challenge of defining and integrating advance time into coordination models remains unresolved despite numerous efforts aimed at optimizing the bandwidth of the green wave and harmonizing traffic flows speed. To provide an experimental estimate of the impact of advance time on coordination plan efficiency, a simulation model of a coordinated arterial segment was developed in the VISSIM, based on the case study presented in HCM 2016. The variable parameter of the model was advance time. Simulation results revealed that the average travel time along the arterial decreases as advance time increases up to six seconds, whereas further increases beyond this threshold lead to a sharp deterioration of traffic conditions on secondary approaches. These findings highlight that incorporating advance time into coordination plan can significantly improve the performance of primary traffic flows within the green wave. At the same time, the results emphasize the necessity of continuous monitoring of traffic demand on secondary approaches to avoid excessive delays and ensure balanced efficiency of the overall traffic control system. Key words: traffic control, coordination plan, signalized intersections, traffic simulation, advance time, VISSIM.
Contemporary Operational Requirements for Road Vehicles
This paper examines modern operational requirements for prospective vehicles — transportation means designed with consideration of future technical, ecological, and social challenges. The study provides a comprehensive analysis of key aspects, including vehicle reliability, safety, fuel and energy efficiency, environmental impact, maintenance strategies, ergonomics, digitalization, cybersecurity, standardization, and regulatory compliance. Emphasis is placed on the integration of active and passive safety systems, predictive maintenance strategies, advanced battery management, and sustainable energy management approaches. The review highlights recent scientific and industrial research, identifies current trends in automotive technologies, and provides practical recommendations for vehicle manufacturers, fleet operators, and service organizations. The paper stresses the importance of life-cycle management, modular design, and digital monitoring systems to ensure reliable, efficient, and environmentally responsible operation. Finally, the study underscores that the development and implementation of a comprehensive operational policy, aligned with international standards and emerging technologies, is crucial to maintaining vehicle safety, performance, and sustainability in the evolving transportation landscape. Developing a method and equipment for analyzing and measuring integral power when monitoring vehicles is a complex but extremely relevant engineering task that covers issues of electromagnetic compatibility (EMC), environmental safety, cyber security, and radio monitoring. The main goal of this research is to determine the integral (total) power of noise emitted by a vehicle, regardless of the type of its power plant (internal combustion engine, hybrid or electric drive system). The analysis is carried out in a specified frequency range, taking into account the characteristics of the engine, electrical equipment, charging systems (in the case of electric vehicles), and switching devices, in particular inverters and pulse width modulation (PWM) systems. Keywords: prospective vehicles, operational requirements, reliability, safety, energy efficiency, environmental sustainability, maintenance, cybersecurity, digitalization.
Research of operation conditions for N1 category hybrid trucks
At the intersection of several key trends—tightening environmental standards for vehicles, relentless urbanization, growing dependence on fuel imports, and the increasing role of light commercial vehicles in e-commerce logistics—the efficiency of the powertrain for N1 category vehicles becomes critically important. N1 category vehicles constitute a significant share of the vehicle fleet, and according to manufacturer data, they operate in urban driving modes for over 75\% of their working time. The most suitable solution for this operating regime appears to be the hybrid powertrain, which has been developed over the last 20 years and is widely implemented in passenger transport. A significant lag in both scientific research and practical implementation of hybrid systems for this vehicle type has been identified. To address this gap, a practical study of the operating conditions of a popular commercial vehicle (Mercedes Sprinter 208 CDI, Euro 6) was conducted under real-world conditions during a typical working day. This provided an empirical basis for further mathematical modeling. Analysis of data from the on-board computer and an OBDII scanner identified specific features of the duty cycle, notably a significant proportion of coasting, accounting for 35% of the route (44.2 km). This confirms the potential for energy recuperation and the use of a hybrid powertrain in conditions with frequent stops. At this stage, a preliminary analysis of data collected from the on-board computer for $20 stops has been conducted. The obtained data were systematized into a tabular form, and graphs of speed and fuel consumption changes were plotted. Data collected via the OBDII scanner, including speed, acceleration, engine load, longitudinal road grade, and the impact of driving style, will be used for further, more detailed analysis. The obtained empirical data will form the basis for subsequent mathematical modeling. This will enable the development of optimal hybrid powertrain configurations, including the power split between the internal combustion engine and the electric motor, as well as the capacity of the traction battery. The research results will not only enhance fuel efficiency—increasing the competitiveness of transport companies by reducing the Total Cost of Ownership (TCO), as confirmed by recent international studies (e.g., TCO for HEV trucks is the lowest)—but will also contribute to reducing harmful emissions, particularly in urban cycles, thereby positively impacting the environmental situation, namely air quality.
Development of an experimental plan for the truck maintenance process at recycling points
The paper discusses the development of a plan for experimental modeling of the process of servicing trucks at cargo handling points, aimed at improving logistics system efficiency and reducing vehicle downtime. The main focus is on simulating vehicle arrival and servicing dynamics under stochastic conditions, considering the principle of relative priority in their order of service. Using empirical data, the laws governing the probability distribution of random variables that characterize freight transport arrival times and service durations were identified. It was found that the arrival process follows the Poisson distribution, and service duration follows the exponential distribution, confirmed by statistical verification using Pearson's criterion. The paper supports the idea that queuing theory and simulation modeling methods are useful for evaluating the efficiency of cargo processing points. A methodological approach to stochastic modeling of the service process is proposed, based on algorithms for randomly generating arrival intervals and service durations within the Microsoft Excel environment using functions that implement Poisson and exponential distributions. The model incorporates the principle of relative priority, enabling adaptive changes in service sequences based on current operating conditions and economic considerations. Study results indicate that implementing multi-channel service systems (with one to three stations) can significantly decrease average queue length and waiting times, while increasing system stability under varying traffic levels. This approach allows for predicting how long a vehicle stays in the system, identifying time losses, and providing recommendations for optimal resource allocation at service points. The findings can also be used for further mathematical formalization of logistics performance indicators and applied to other transport networks. Overall, this research advances analytical and predictive methods in transport logistics, offering opportunities to reduce freight transport downtime and enhance the economic stability of cargo handling systems in current conditions. Key words: truck, modeling, freight transportation, processing point, queue, relative priority, waiting time.
Research of parameters of the technology of restoration of parts by plastic deformation
Nowadays, there is a need to improve the technical maintenance system of agro-industrial enterprises. Increasing the service life of machines is a priority task of the technical maintenance industry. Developing progressive technologies for repairing machinery is a priority task for our country. Achieving a high level of reliability and durability of equipment is possible only through a comprehensive solution to the tasks of the technical maintenance industry. Modern high-performance and resource-saving technologies for restoring equipment life, repairing machines and restoring worn parts are needed. The use of plastic deformation methods in the processes of manufacturing and repairing machine parts allows for high-quality and effective shaping. Plastic deformation processes in the restoration of worn parts have limited application.There is a need for research into the application of plastic deformation in the restoration of specific parts. Gear pumps are an important part of hydraulic systems of machines. The main malfunctions of hydraulic system units are: a drop in volumetric efficiency, deterioration of control, and violations of unit adjustments. Wear of pump bushings leads to a drop in volumetric efficiency, deterioration of control, and violations of unit adjustments. Wear of pump bushings leads to a drop in volumetric efficiency, deterioration of control, and disruption of unit regulation. It is necessary to develop an optimal technology for bushing restoration. The paper presents an analysis of the operating conditions of oil pumps and the characteristic defects and wear of bushings. It shows that worn bushings can be restored. Working tools have been developed to carry out the process of settling worn bushings. To carry out the process of sedimentation of worn bushings, working tools were developed. We substantiated the modes of restoration of bushings and proposed a heat treatment mode. Аrtificial aging for 6 hours at a temperature of 180°C. It was concluded that plastic deformation could be used to restore bushings. Keywords: pump, resource, bushing, recovery, durability, wear, volume, plastic deformation, distribution, sedimentation.
The Use of Mechanical Engineering Technologies in the Repair and Restoration of Parts
The economic efficiency of parts restoration lies in the fact that the cost of restoration is usually lower than the cost of new parts, since the process requires relatively little labor and time, as well as low material expenses. One of the best and most advanced methods of restoring parts is the application of galvanic coatings. The problems and opportunities associated with the application of galvanic coatings to automotive components during repair and restoration are considered. Galvanization processes are associated with the need for expensive equipment, high consumption of energy, water, and chemical materials, as well as harmful effects on the environment. In the absence of automobile repair plants, this method of restoration can be attributed to mechanical engineering technologies. The main methods include hardening, chrome plating, nickel plating, and others. The choice of a suitable metal for galvanic coating mainly depends on such criteria as coating cost, surface microhardness, coating time, reflection coefficient, as well as environmental factors. The technical decisions regarding the choice of an appropriate galvanic coating were determined using the Analytic Hierarchy Process (AHP). This is a mathematical-logical decision-making method that helps to select the best option among several alternatives when multiple criteria are considered. By choosing a metal for galvanic coating that meets different criteria, the most appropriate coating for automotive parts was determined. Nickel proved to be the most prioritized option. Keywords: automobile repair, automotive parts restoration, galvanic coatings, Analytic Hierarchy Process, coating selection criteria.
Assessment of the influence of nonlinear characteristics of suspension components, shock absorber, on the results of their diagnostic
Shock absorbers in a car are a key element of the suspension, which provides comfort and safety when driving. They work in tandem with an elastic device, absorbing the energy of impacts and shocks that occur when driving over uneven roads. The shock absorber prevents body swaying, reduces vibration and provides a smoother movement of the body. In the process of operation, the parameters of the shock absorber decrease, safety and comfort, vehicle performance decrease, vehicle stability deteriorates, braking distance increases, body swaying progresses when driving, knocks and noises appear in the suspension, uneven tire wear. This necessitates periodic monitoring of the shock absorber condition using diagnostics. There is a widespread lack of disassembly diagnostics, fragments of installation and dismantling robots are very labor-intensive, requiring the need for special equipment and qualified specialists. In practice, bench diagnostics are used by activating the suspension with a periodic signal, in which, to a large extent, it is not the shock absorber that is tested, but the suspension. Therefore, when testing the assembled suspension, the shock absorber testing section contains information about other suspension components. This is a source of errors in shock absorber diagnostics. Suspension components can have both linear and nonlinear characteristics, and both of them, through the presence of errors and untimely replacement of the shock absorber, can limit its actual performance. In this paper, using the simulation modeling method, the influence of nonlinear characteristics, such as dry friction and play in the suspension, on the error in shock absorber diagnostics is considered. Keywords: shock absorber, diagnostics, nonlinear characteristics, errors, modeling
Analysis of the influence of traction system elements of heavy tractors on soil pressure
Soil compaction is a physical process of soil degradation that reduces its porosity and, as a result, intensifies erosion processes and decreases crop yields. Plants grown on compacted areas exhibit weaker development and lower vitality. This occurs because gas exchange in the soil deteriorates, affecting the availability of oxygen and other gases to plant roots.Modern crop production practices show that the widespread use of heavy tractors in fields increases both the intensity and frequency of mechanical impact on the soil. Repeated movement of agricultural machinery leads to significant compaction of the soil to a depth of up to 100 cm, while machine tracks may occupy up to 80% of the cultivated area. Under the influence of heavy machinery, soil density has increased by 20–40%. Reducing soil compaction is therefore one of the key strategies for sustainable land use. Improving the running systems of machines and implements, as well as reducing their overall weight, plays a crucial role in this process. This study established that manufacturers of heavy, high-power tractors are constantly seeking ways to reduce the specific pressure exerted on the soil, particularly through modifications in design parameters, production technologies, and materials used in drive components. The efficiency of such tractors depends significantly on the proper selection of wheel configurations, especially during operations that require minimal soil impact. The study analyzed the structural features of traction systems in modern high-power tractors designed to reduce ground pressure. In particular, models of wheeled tractors with an engine power of 300–500 hp were examined; the specific ground pressure was calculated; and the obtained values for tractors with wheeled, semi-tracked, and fully tracked propulsion systems (in the 300–500 hp range) were compared. A similar analysis was also carried out for tractors with a power output of 500 hp.
Modeling the influence of road humps parameters on the operation of an uncontrolled intersection
The article investigates the influence of the design parameters of road humps on the speed of vehicles and the operation of uncontrolled intersections. Proper design of road humps provides a reduction in speed and increased safety, while errors in the selection of parameters lead to increased delays, additional fuel consumption, and increased emissions. The aim of the study is to develop models for predicting changes in vehicle speed depending on the geometric characteristics of the road hump. For this purpose, a series of experiments was conducted in the PTV VISSIM environment with changes in width (1–3 m), height (0.03–0.10 m), and distance from the stop line (10–50 m). The height was taken into account through the parameters of the speed reduction zone. Processing the results in STATISTICA allowed us to build regression models with high adequacy (R² = 0.83–0.92). It was established that the height of the road hump has the greatest impact on speed reduction, while the width and distance to the stop line determine the nature of deceleration in a more complex relationship. The optimal selection of parameters allows for the provision of the effect of traffic calming without significant loss of capacity and with minimal environmental consequences. The results can be used in transport planning, design of the street and road network, and in assessing the effectiveness of traffic calming measures in Ukrainian cities. Key words: road hump, vehicle, traffic flow, simulation, speed, height, width, distance from the stop line, microsimulation, model.
Types of thermal regulation systems of the traction battery of an electric vehicle and their analysis
The increase in the production of electric vehicles (EVs) largely depends on the reliability and safety of the main components and assemblies. One of the most expensive and dangerous parts of an EV is the power (traction) electric battery. Lithium-ion batteries (Li-ion) have become the most widespread. An important characteristic that affects their safety is performance and service life. These battery indicators depend on the average operating temperature, which must be in the optimal range to prevent a number of negative phenomena. That is why the operation of thermal control systems (TCS) of EV battery packs is important to ensure correct functioning in any environmental and operating conditions. Lithium-ion (Li-ion) batteries have become the dominant technology for the automotive industry due to some unique features, such as high power, capacity, storage capacity and a large number of possible recharges. However, under deep discharge conditions, a large amount of thermal energy is generated due to redox reactions, and the battery temperature increases excessively and uncontrollably with possible subsequent self-ignition. Therefore, it is necessary to develop such a battery cooling system to prevent damage to the cells due to high operating temperatures. Other problems arise when Li-ion batteries reach temperatures below optimal values, such as the inability to release energy or rapid degradation and capacity reduction. That is why an effective system is needed that can heat the device to reach the optimal temperature range, i.e., a thermal management system (TMS). Keywords: electric vehicles, thermal management, safety, lithium-ion battery, heat transfer, energy efficiency
Optimization of Operational Planning for Freight Road Transport Taking into Account the Specifics of Small Batch Delivery
The article investigates methods for managing the operational planning of freight road transport with a special focus on organizing the delivery of small cargo batches based on logistics principles. General challenges of operational planning, such as market dynamics and condition uncertainty, as well as specific problems of small batch transportation (low utilization, empty runs, complexity of routing numerous points), are analyzed. Classical and modern planning methods (exact, heuristic, metaheuristic, simulation, AI methods) are reviewed and compared based on criteria of solution quality, computational speed, and flexibility. A structural model of a consolidation network for small batches and a mathematical model for route optimization, considering costs, time, load factors, and time windows, are proposed. A heuristic algorithm for the practical implementation of the model, including order classification, batch consolidation, and routing methods (Clarke-Wright, 2-opt), is considered. The possibilities of integrating planning methods with modern IT (GPS, TMS) are analyzed. An example calculation and an assessment of the economic efficiency of the proposed approach for a regional network are provided. Recommendations are given for selecting methods and implementing logistics principles to improve the efficiency of operational transportation planning, especially for small batches, in the context of Ukraine. Keywords: operational planning, freight road transport, small cargo batches, consolidation, logistics, management methods, route optimization, mathematical model, efficiency, TMS.
EXPERIMENTAL EVALUATION OF METHODS FOR CALCULATING VEHICLE ACCELERATION TIME
The article demonstrates that the advancement of automobiles inevitably leads to a dramatic increase in the complexity of the mathematical description of their motion. Modern vehicles are complex technical systems comprising numerous interconnected components and subsystems - electronic, mechanical, hydraulic, and pneumatic - each of which influences the overall dynamic properties of the vehicle. Consequently, the use of simple analytical relationships becomes ineffective: they do not fully account for the real physical processes occurring during acceleration, braking, gear shifting, or changing road conditions. To calculate acceleration time standards during vehicle diagnostics, it is advisable to use numerical methods that allow for the consideration of a large number of parameters, including engine power and torque, transmission characteristics, air and rolling resistance, mass distribution, and road surface conditions. Such methods ensure the required accuracy regardless of the complexity of the mathematical model and allow for the description of nonlinear processes, transient conditions, and random parameter deviations. The use of numerical models also opens up extensive opportunities for conducting virtual tests and preliminary predictions of vehicle performance without the need for costly in-kind experiments. This is especially important when developing automatic diagnostic systems that can analyze unit operating parameters in real time and identify deviations from the norm. Furthermore, numerical methods make it possible to optimize vehicle design at the design stage, select optimal engine and transmission operating modes, reduce fuel consumption, and improve driving safety. The ideas presented in the article are supported by calculations of specific examples and a comparison of the obtained results with experimental data, demonstrating the validity and practical applicability of the proposed approach. The results of this work can be used in the development of intelligent technical control systems, modeling vehicle dynamics, and improving methods for assessing their performance. Key words: car, wheel, acceleration, calculation, numerical methods, discretization, step, Hyundai Accent, Honda Accord.
INFLUENCE OF LASER WELDING PARAMETERS ON THE GEOMETRY OF WELDED JOINTS OF THIN-SHEET STAINLESS STEEL AISI 304
Laser welding is one of the most promising methods of joining metals, combining high precision, minimal thermal deformation, and the possibility of process automatization. Due to the high energy density of the laser beam, the technology provides deep penetration with a narrow heat-affected zone, making it effective for welding corrosion-resistant austenitic steels, in particular AISI 304. At the same time, the peculiarities of thermal processes in laser welding, such as intense heating and rapid cooling of the metal, significantly affect the formation of the structure and properties of the welded joint, so the choice of optimal modes is crucial for preventing defects and ensuring high quality of the welded joint. The paper presents the results of an experimental and statistical study of the laser welding process of 1.5 mm thick AISI 304 steel using response surface methodology (RSM). The aim of the study was to determine the patterns of influence of the main parameters of laser welding on the formation of the geometry of the welded joint. Based on a factorial experiment, regression models were developed to describe the change in the area and width of the weld depending on changes in process parameters. Analysis of the results has shown that the main factors determining the geometry of the joint are the power of the laser radiation and the welding speed. Increasing the laser power contributes to an increase in the weld area, while increasing the speed reduces it. At high values of laser radiation power, the process becomes more stable, and the weld geometry becomes less sensitive to parameter changes. Laser beam defocusing has a negligible effect, only slightly increasing the width of the weld. The most pronounced interaction was found to be between power and speed, which tends to determine the maximum values of the weld area. The developed regression equations with a deviation of less than 10% confirmed the adequacy of the model and the effectiveness of using RSM to predict the geometry of the welded joint. The optimal welding modes identified in the study ensure the formation of high-quality, defect-free joints that defect-free joints and correspond to quality level “B” according to EN ISO 13919-1:2019. Keywords: laser welding, thin-walled products, welding process optimization, response surface methodology, stainless steels, AISI 304.
THE ROLE OF ARTIFICIAL INTELLIGENCE IN BUILDING ADAPTIVE AND SUSTAINABLE SUPPLY CHAINS
The article explores the role of artificial intelligence (AI) in the digital transformation of logistics systems. It highlights the practical benefits of AI integration, including optimization of supply chain management, predictive demand modeling, reduction of operational costs, increased delivery speed, and improved customer service quality. Particular attention is given to the contribution of AI to sustainability by analyzing CO₂ emissions, supporting the use of alternative fuels, optimizing packaging cycles, and providing tools for ESG-oriented strategies. The study also identifies new professional roles emerging within logistics, such as logistics data analysts, AI system architects, digital twin engineers, and specialists in AI ethics in supply chains. At the same time, challenges related to data unification, cybersecurity, standardization of APIs, and compliance with regulations on automated data processing are underlined. From an engineering perspective, successful AI implementation requires compatibility of hardware and software infrastructure, reliable communication channels, and protection against cyberattacks. The article emphasizes that the effectiveness of AI deployment depends not only on technology availability but also on organizational maturity, readiness for change, and data-driven decision-making culture. It is concluded that logistics of the future will evolve into an intelligent ecosystem where human and artificial intelligence complement each other, forming autonomous, adaptive, and sustainable supply chains, thus strengthening global competitiveness and resilience in conditions of uncertainty. Keywords: artificial intelligence, supply chain management, digital transformation, sustainability, predictive analytics, automation.
MODELING OF ADDITIONAL TIME COSTS IN THE ROAD TRANSPORT SYSTEM AT THE LAST MILE STAGE
The article addresses the problem of optimizing loading and unloading operations in road transport as a key element of the transport and logistics process that significantly affects the overall efficiency of freight delivery. It has been established that considerable time expenditures during the execution and waiting for loading and unloading operations lead to increased operating costs and reduced fleet productivity. An analysis of the regulatory framework showed that the existing regulations were developed under the conditions of a centralized economy and do not correspond to modern market requirements. The necessity of updating these standards has been substantiated, taking into account contemporary conditions and the characteristics of vehicles, types of packaging, as well as the specifics of goods and organizational approaches to logistics operations. The use of regression models has been proposed to formalize the dependencies between the duration of loading and unloading operations and the key parameters of the process. The obtained values of time parameters can be incorporated into the construction of linear and regression models, which will ensure greater accuracy in predicting time expenditures and in developing recommendations for improving the efficiency of transport and logistics systems. The integration of regulatory, mathematical, and digital approaches to the optimization of loading and unloading operations in last-mile retail logistics is identified as a necessary condition for enhancing the effectiveness of logistics processes under current market conditions. Keywords: loading and unloading operations, road transport, logistics processes, transportation efficiency, regression modeling, time expenditures, last mile.
USING CLUSTER ANALYSIS TO STUDY THE CHARACTERISTICS OF MICRO-FREIGHT FLOWS OF SHOPPERS
The article presents the results of a study aimed at identifying socio-demographic and behavioral factors influencing people’s choice of transport mode during shopping trips. Considering the increasing volume of shopping-related trips and the growing attention to the environmental aspects of urban mobility, the study examines the phenomenon of micro-shopping flows as part of the broader urban freight transport system. The study is based on an online survey of 479 respondents. Using hierarchical clustering, two main clusters of shoppers were identified. The first cluster consists of middle-aged individuals, predominantly women, who combine active employment with medium-weight purchases (2–5 kg), mostly during daytime hours, and prefer traveling by private car or on foot. The second cluster primarily comprises students who make small purchases (up to 2 kg), more often after 3:00 p.m., often combining public transport and walking. The results confirm the presence of statistically significant differences between the groups in terms of age, gender, occupation, shopping time, and purchase weight. A clear relationship was found between purchase weight and choice of transport mode: as the weight increases, the likelihood of using a private car rises significantly. Similarly, temporal characteristics influence modal choice — walking predominates in the morning hours, while the share of car and public transport trips increases in the afternoon. The practical significance of this study lies in providing a scientific basis for developing targeted sustainable transport planning measures aimed at specific user groups. For young people, it is advisable to focus on improving access to public transportation and developing micro-mobility infrastructure. For the working population, effective measures may include incentives to reduce private car use. Future research prospects are related to modeling the impact of micro-shopping flows on overall urban traffic. Such analysis is important for managing peak loads in the transport system and for developing policies aimed at the environmentally sustainable development of urban transport. Keywords: shopping trip, cluster analysis, socio-demographics indicators, mode choice, micro freight flows
IMPROVING THE TECHNOLOGY FOR MANUFACTURING ELECTRIC VEHICLE TRACTION BATTERY HOUSINGS TO PROTECT AGAINST IMPACT DAMAGE
On modern electric vehicles, the traction battery is installed from below on the bottom of the body, which reduces the height of the vehicle's center of gravity and improves the vehicle's lateral stability during curved movement. The disadvantage of this arrangement is the increased risk of damage and destruction of the protective housing and, accordingly, the battery's electrical elements, which are dozens of ordinary household lithium-ion batteries of the AAA type. But the housings of these electrical elements are manufactured using a special technology that helps increase the strength of the housing and from a material with high heat dissipation. It is shown that the traction battery is the most expensive component of an electric vehicle. Therefore, the development of production methods aimed at increasing its service life is an urgent task. The mechanical characteristics of anisotropic material were taken into account during the manufacture of reinforced containers for electrical element housings. Data were determined that reliably reflect the influence of the stretching coefficient, planar anisotropy and the initial diameter of the work piece on the critical thickness of its plate. An expression was obtained that takes into account all the characteristics of the technological process that affect the thickness of the initial work piece. This allows you to control these characteristics in order to optimize the thickness of the work piece. The dependence obtained as a result of the study allows you to accurately and qualitatively calculate the optimal thickness of the initial work piece at the stage of developing the technological process for manufacturing battery cell housings for electric vehicles. Key words: electric car, lithium-ion battery, battery protection, anisotropic materials.
MATHEMATICAL MODELLING OF THERMOMECHANICAL STATE IN ADDITIVE MANUFACTURING AND WELDING OF TITANIUM ALLOYS FOR TRANSPORT ENGINEERING
This study demonstrates a detailed investigation of residual stress distribution and thermomechanical behavior in Ti80 and Ti-6Al-4V titanium alloy components subjected to welding and post-weld treatments, integrating both experimental measurements and finite element simulations. The aim of the study is to evaluate the influence of welding sequence, thermal cycles, and temperature-dependent material properties on stress evolution, with particular emphasis on transverse and longitudinal residual stresses concentrated near weld toes. The relevance of this research is determined by the high demands for reliability, dimensional stability, and fatigue resistance of welded titanium components in transport, aerospace, and engineering applications. Significant anisotropy in stress distribution was observed along and across weld seams, highlighting critical regions prone to distortion or fatigue initiation. The novelty of this research lies in the comparative analysis of two titanium alloys under different welding conditions, combining experimental results with numerical simulations to provide a comprehensive understanding of residual stress development and thermomechanical responses. The work further demonstrates the effectiveness of post-weld heat treatment (PWHT) and local stress-relief procedures in mitigating residual stresses, enhancing both dimensional stability and fatigue performance. Practical implications of this study include guidance for optimizing welding parameters, implementing appropriate post-weld treatments, and improving the reliability and service life of high-performance titanium components in transport, aerospace, and engineering applications. The findings contribute to the broader understanding of the interplay between welding conditions, material behavior, and stress evolution, offering a foundation for improved predictive modeling and informed design decisions in welded titanium structures, and highlighting the significance of temperature-dependent properties in accurately forecasting residual stress fields and deformation patterns. Keywords: Ti80, Ti-6Al-4V, residual stress, thermomechanical properties, post-weld heat treatment, FEM, welding, additive manufacturing.
FUNCTIONAL ADAPTATION IN A GRAIN CARRIER WHEN THE MASS OF TRANSPORTED GRAIN IS UNSTABLE
The methodology of functional adaptation of a grain truck by adjusting the speed depending on the density of the transported grain crop is proposed. As a result of studying the functional adaptation of a grain truck with an unstable mass of transported grain, it was found that fluctuations in the grain cargo during transportation significantly affect the stability of the vehicle, especially during maneuvering and braking. When estimating the weight of a grain truck, the density of the transported grain must be taken into account. The volumetric carrying capacity of a grain truck is carefully assessed by establishing a functional dependence on such parameters as nominal carrying capacity, volumetric carrying capacity, body volume, and cargo volume. The dynamic space of grain truck operation is based on a metric state space, each element of which fully determines the state of the system under consideration according to certain functional parameters. If one or more functional parameters of the grain truck are unstable and deviate from their nominal values, the grain truck may lose its functional stability and not perform the functions defined by the regulatory and technical documentation. In such cases, the dynamic operating space is characterised by transfer functions that provide a mathematical basis for analysing the behaviour of the system. During the operation of a grain truck, the task of ensuring its functioning in one of two areas is solved: the area of operation or the area of optimal operation. To ensure that the grain carrier operates in the optimal region, it is necessary to select such nominal values of functional parameters and tolerance fields to ensure the position of the spread and outputs in this region. Keywords: functional adaptation, grain carrier, grain mass, mass instability, acceleration, equation of motion.