International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The use of aircraft-type unmanned aerial vehicles (UAVs) is considered. The advantages, disadvantages and limitations of specific configurations of the UAV body are described. The requirements for simultaneous assessment of materials are described, with an emphasis on modern composite materials forming structurally reinforced or three-layer structures of some UAV elements. It is proposed to take the mass efficiency coefficient of the model as a basis for comparison of aircraft-type UAVs, which determines what part of the mass of the considered design corresponds to the requirements of users. A static analysis of the fuselage and wings of aircraft-type UAVs, made with new materials, was carried out, determining the parameters and their shapes in order to reduce the bending moment acting on the structural elements of the wing, which would reduce its weight. Safety coefficients for the operation of aircraft-type UAVs with certain materials and the financial situation in their design based on forecasting time series of changes in the requirements for the use of UAVs are proposed.

The effect of inclusions and corrosion products on the mechanism of wear of railway wheels made of R7 steel and also of rails made of R7 steel M76. was studied. The research was carried out by several methods: metallographic, electron microscopy, X-ray, micro-X-ray spectral analysis. The features of the formation of wear particles near nonmetallic inclusions and corrosion products related to structural changes near the treads of railway wheels and rails as well as to the interaction of steel with the surrounding atmosphere during operation were investigated. The influence of various factors on the role of nonmetallic inclusions and corrosion products in the formation of wear particles is shown, which makes it possible to predict the nature of wear of the rolling surface of railway wheels and rails under various operating conditions. The main sources and the mutual influence of various factors on the formation of wear particles near nonmetallic inclusions and corrosion products have been established, which makes it possible to predict the nature of wear of the rolling surface of railway wheels and rails under various operating conditions.

Variability is a fact of industrial production. Every process produces products that are not exactly the same. For successful quality control and management, several different methods of preventive quality assurance have been developed in the early stages of the product development process. The SPC method is used in conditions from the initial process batches and in the stages of serial production. The SPC statistical process control method is indispensable for a modern, future-oriented manufacturing company. In this paper, I would like to present the SPC statistical method on a practical example from the motorcycle industry, with measurement results under the conditions of the first pre-series of a complex welded steel component.

This paper deals with the possibility of renovating exterior plastic automotive components using adhesive bonding technology. The research focuses on the evaluation of the shear strength of adhesive joints formed using adhesive systems commonly applied in automotive repair practice. The experimental investigation was carried out using selected adhesives, and the shear strength of the bonded joints was evaluated. To simulate real operating conditions of vehicles, accelerated laboratory tests were performed in which the bonded joints were exposed to various degradation environments. Subsequently, changes in the shear strength of the adhesive joints were evaluated after their exposure to these conditions. The study also examined the influence of road de-icing agents commonly used in winter road maintenance on the quality and integrity of the adhesive joints. Based on the analysis of fracture surfaces, the failure mechanisms of the joints were identified and classified as adhesive or cohesive failure. The obtained results provide a basis for assessing the applicability of adhesive bonding technology for the renovation of exterior plastic automotive components and contribute to the optimization of repair procedures used in automotive maintenance practice.

The paper examines a specific type of industrial elevator known as the hoist elevator that is used for lifting and lowering various materials. These elevators are used in various construction yards and usually are mounted close to the building being constructed. The elevator consists of many mechanical and electrical parts, and besides lifting and lowering the loads and the cage, it needs to stop at a certain height to unload. The vertical motion process is controlled by the operator on the ground. The work operation analyzed in this paper is load lifting from the ground up to a certain height. During this process, the elevator is heavily loaded, and oscillations will appear due to the lifting process. The type of analysis is dynamic analysis, and the methodology consists of 3D modeling of the elevator and carrying simulations with SimWise 4D software. This enables analysis of the lifting dynamics and identification of the nature and extent of forces, torques, and stresses on the elevator parts and the form and intensity of the oscillations. Results will be presented in graphical form and discussed. Conclusions from this study will be useful for motion dynamics, strength of elevator parts, and safety at work. The Hoist elevator is modeled based on the technical data from the manufacturer.

This study presents a mesh-converged finite element assessment of functionally graded spur gears. Two gear models are studied: a fully graded gear and a half-metal/half-graded gear. The material properties vary gradually from aluminum alloy to zirconia according to power-law distribution. The modal analysis is carried out in ANSYS using SOLID187 elements and the Block Lanczos method. A mesh-convergence study is performed, and a 0.25 mm mesh is adopted for the results. The study compares the natural frequencies and normalized mode-shape profiles of the two models. The results show how the material layout influences the vibration behavior of the gear.

: In this paper are investigated and presented the most influential operating parameters and the guidelines for proper arrangement of pumps in the condensing/feedwater heating system. The observed system operates in marine steam propulsion power plant. In the analyzed system operates three pumps: Condensate Pump (CP), Auxiliary Pump (AP) and FeedWater Pump (FWP). Considering all observed pumps, FWP is the dominant mechanical power consumer because it operates with the highest pressure difference and with the highest fluid mass flow rate. Used mechanical power and losses (energy and exergy) of all observed pumps are directly proportional to fluid mass flow rate through the pump – higher fluid mass flow rate through the pump will result with higher mechanical power used by pump and with higher losses (both energy and exergy) and vice versa. Energy and exergy efficiencies of the observed pumps have reverse proportional trends. The most influencing factor related to the pump efficiency (both energy and exergy) is the pump inlet pressure. Pump inlet pressure is directly proportional to the pump exergy efficiency, but simultaneously pump inlet pressure is reverse proportional to pump energy efficiency.

The current optimization of materials in the automotive industry is primarily driven by the objective of progressively reducing vehicle curb weight, which serves as a critical instrument for lowering greenhouse gas emissions and enhancing energy efficiency. Empirical data demonstrate a direct correlation between weight reduction and fuel consumption: a 10% decrease in vehicle mass generates an approximate 7% reduction in fuel consumption. Composite materials, defined as heterogeneous systems consisting of at least two components—a continuous matrix (binder) and a discontinuous reinforcement (fibers, particles, or layers)—enable a synergistic effect of mechanical properties that are unattainable with monolithic metallic materials. In structural applications, polymer matrices (including both thermosets and thermoplastics) predominate in combination with high-strength carbon, aramid, or glass fiber reinforcements. These material systems exhibit extreme specific strength, a high modulus of elasticity, fatigue resistance, and anisotropic properties that allow for the directional optimization of stiffness. For components requiring maximum dimensional stability and self-supporting (monocoque) capabilities, sandwich configurations are utilized, typically integrating an aramid honeycomb core between high-performance composite face sheets. The qualitative parameters of the resulting components are directly dependent on the chosen manufacturing technology and the fiber-to-resin ratio. The Vacuum Infusion (VI) method represents a highly efficient process in which a vacuum-sealed mold ensures the uniform saturation of dry reinforcement with liquid resin. This procedure minimizes porosity, achieves a high fiber volume fraction—reaching up to 70% in advanced systems—and guarantees high production reproducibility and surface quality without the need for secondary machining. Despite their technical superiority, the primary limiting factors for widespread implementation remain the high economic cost of raw materials and the complexity of manufacturing cycles. Prospective development is focused on streamlining processes for mass production, implementing sustainable bio-fibers as reinforcing components, and addressing the challenges of recyclability and component replacement at the end of the life cycle. Advanced composite structures thus form the essential material foundation for the next generation of ultra-lightweight and safe transport vehicles.

This paper presents a comparative finite element assessment of the thermo-mechanical severity of automotive brake discs for Mercedes-Benz A180, E220 and E350 under intensive and repeated braking cycles. Transient thermal and structural simulations were evaluated for 27 cases covering high-speed, interurban and urban braking profiles. Gray cast iron EN-GJL-250/G3000 was used as the disc material, while heat flux, convection and radiation were considered as thermal boundary conditions. Maximum temperature, heat flux, total elastic deformation and von Mises stress were normalised and combined through several severity-index scenarios. The results show that the repeated 120-0-120-0 km/h braking cycle is the governing condition for all vehicles. A180 reached the highest raw temperature, stress and deformation, while the equal-weight severity indices confirmed the same critical braking profile within each vehicle group. All cases remained below the selected thermal and mechanical limits.

This study investigates the application possibilities of ultrasonic testing for quality control of resistance spot welds used in the automotive industry. Experimental resistance spot welds were produced on galvanized DP600 and H420LAD steel sheets using different welding current values. The weld quality was evaluated by metallographic analysis, EDX surface analysis and several ultrasonic testing approaches, including automatic C-scan evaluation and manual A-scan interpretation. The obtained ultrasonic results were correlated with metallographic observations and macrostructural characteristics of welded joints to assess the sensitivity of ultrasonic methods for detecting weld imperfections and evaluating weld nugget formation. The results confirmed that welding current significantly influences weld geometry, weld nugget formation and the occurrence of internal defects. Among the samples investigated, the most acceptable weld quality was achieved at a welding current of 7.6 kA for both investigated steel grades. The study also demonstrated the potential of advanced ultrasonic testing methods for rapid and reliable non-destructive inspection of resistance spot welds in automotive manufacturing.

Tribological properties of functional surfaces are a key factor influencing the durability, reliability and efficiency of mechanical systems. One of the progressive approaches to surface modification is laser surface microtexturing, which allows for the precise creation of controlled microstructures capable of modifying contact conditions and lubricant retention at tribological interfaces. This article focuses on the application of laser-induced surface microtexturing to improve the tribological performance of hard nanocomposite coatings nACRo³ and nACRo⁴. The experimental part of the research is dedicated to the preparation of microtextures on the substrate surface using a pulsed laser system, followed by the deposition of nanocomposite coatings nACRo³ and nACRo⁴. The created microstructures are characterized in terms of their geometry, distribution and influence on the contact properties of the coated surfaces. The wettability of the microtextured surfaces was evaluated based on the measurement of the contact angle. Optimizing surface microtexture is an effective way to increase wettability and potentially improve lubrication conditions during technological processes of forming or tribological loading of materials.
Keywords: laser surface texturing, tribology, nanocomposite coating, wettability, contact angle, PVD coating, tool steel, die casting

The question of application of unmanned aerial vehicles (quadrocopters or multicopters) with electric drive for long-term monitoring operations in territories with operating power system or electrified railroad transportation is considered. The disadvantage of drones of this type is the limited capacity of the on-board battery, which implies the need to recharge it, i.e. to stop the flight and return the aircraft to the base. The authors propose a constructive solution to this problem, which is based on a non-contact (induction) method of charging during the flight of an aircraft due to the energy of the electromagnetic field arising from the flow of electric current in the highvoltage wires of the power system or the contact network of railroads. For this purpose, an additional circular electric winding is installed on board the aircraft, in which an electromotive force (EMF) is induced in the electromagnetic field during flight. This EMF is used to charge the battery of the unmanned aerial vehicle. Also, in the proposed design of the unmanned aerial vehicle, solar panels are provided for recharging the batteries during the flight during daylight hours.