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When electrical energy is drawn by electric vehicles from charging stations at charging process the voltage drops and increased current loading of cable lines in distribution grid occur. Inasmuch the electrical grid is insufficiently dimensioned or at large amount electric vehicles concurrently charges without controlled charging system, the voltages could decrease under desired level in grid points. This leads to the deterioration of voltage quality in given grid. The higher cables current loading leads to active power losses increase and decrease their service life. The paper describes the utilisation of modelling the electric vehicles when charging by power load model in physical diagram implemented into alternative simulation software. The created charging station load model is used for solving of voltage studies in distribution grid and for the analysis of cable lines ampacity. The grid contains a small number of points and low penetration of charging stations. Voltage levels are solved when random operation of charging stations during the working day without controlled system. For other loads, the typified daily loads diagrams of households are used.

A soil processing belongs among basic steps in an area of a crop farming. The research was focused on increasing a service life of ploughshares by an overlaying technology. The research within field conditions was focused on innovations of ploughshares in the area of a conventional processing of the soil by means of the overlaying technology. A new functional profile was created by means of overlaying electrodes on the conventional tool in order to respect drainage of the processed soil, i.e. oblique overlays. The overlaying material was put in the most stressed places of the ploughshare, i.e. parallel with a face and an edge and these both in a front as well as in a back part. New functional surface was distinguished for a reinforcement of a top of the ploughshare edge and the back part of the ploughshare. Overlaying material was of carbide type OK Tubrodur 15.82. Within the tools service life testing under the field conditions the change of the tools shape and their mass loss were investigated. Statistical methods were used for evaluating of the experiments.

In this paper, the electric discharge perforation technology is used to preset surface texture, which effectively suppresses the generation of large cutting forces in the hard cutting process, avoids the aggravation of tool wear, and improves the service life of the tool. Use CBN tools to hard-cut GCr15 hardened steel, design three-factor non-textured orthogonal cutting simulation and experiment about cutting depth, cutting speed, and feed rate, and use range, variance and signal-to-noise ratio methods to simulate and experiment data is analyzed to determine the best combination of cutting parameters and the degree of influence of each parameter on the cutting force generated in the hard cutting process. Use the best combination of cutting parameters to hard-cut GCr15 hardened steel with a preset surface texture, observe the tool wear, measure the cutting force, compare and analyze the results under the same cutting conditions without texture to verify the preset surface texture can effectively reduce tool wear and increase tool life.

Cycloid gear drive is widely used in robot cycloid planetary reducer, and the transmission accuracy is the key property of the reducer. The standard cycloid transmission is a multi-tooth mesh. The modification method has attracted extensive attention as one of the important parameters of the cycloid drive. The influence of the isometric and shifting modification of the cycloid gear on the cycloid transmission backlash was analysed according to the characteristics of the multi-tooth mesh and the profile equation of the modified cycloid gear in this study. Combined with the backlash analysis, a multi-objective optimization mathematical model of cycloid gear modification parameters was established to ensure the backlash and strength of the reducer. The study showed that the modification combination mode and parameters were obtained under different application conditions, thus providing a certain reference for the modification parameter design of cycloid transmission.

Due to the complexity of the current industrial pipeline layout, in order to improve the efficiency of pipeline inspection and maintenance, a multi-functional obstacle-surmounting pipe-crawling robot was designed to address the issues of varying pipe diameters and positions. The movement pattern of the crawling robot was studied, the variation of the clamping force of the clamping mechanism during the climbing process was analyzed, and the mapping relationship between various parameters was obtained as the basis for later kinematic simulation. The design of inverted V, positive V and other drive combinations and the planning of multi-functional obstacle-surmounting actions were conducted to verify the rationality of the structural design and the stability of the motion process of the multi-functional obstacle-surmounting pipe-crawling robot. Results showed that the multi-functional obstacle-surmounting pipe-crawling robot can achieve the expected crawling speed of 0.3m/s when moving on a horizontal pipeline, and the motion process is stable. When moving on a vertical pipeline, from the speed and displacement curve of the robot on the x, y, and z axes, it can be seen that the speed and displacement of the pipe-crawling robot are steadily increasing without any left or right swing, indicating that the clamping mechanism works well and the structural design is reasonable.

This article presents the development and validation of SBRI (Small Business Digital Maturity Assessment and Road to Industry 4.0), an innovative methodology for assessing digital maturity and supporting digital transformation specifically designed for small manufacturing enterprises in the context of Industry 4.0. Unlike existing models, which are often too complex or unsuitable for smaller organizations, SBRI considers the unique characteristics and constraints of small businesses. The methodology includes five key dimensions: Strategy, Technology, Process, People, and Organization, elaborated into 25 subdimensions with specific maturity criteria and indicators. The SBRI includes a structured roadmap for digital transformation through a proposed digital maturity continuous improvement cycle. An empirical study involving 23 small manufacturing enterprises in the Czech Republic has demonstrated the validity and practical applicability of the methodology. The results showed an average level of enterprise digital maturity of 0.9 on a scale of 0 – 4. These findings suggest that small businesses are just at the beginning of their digital transformation journey. Therefore, the SBRI methodology represents a valuable tool for navigating small businesses through their digital transformation journey, contributing to academic discourse and practical application of Industry 4.0 principles in the small business segment.

The study focuses on an evaluation of mechanical properties of the H13 tool steel manufactured by the material extrusion and further comparison with conventionally produced material. Notably, for achieving sufficient surface quality of functional parts further post-processing is required. Thus, a comprehensive investigation, encompassing hardness, ultimate tensile strength (UTS) and yield strength (YS) measurement, microstructure, and machinability was performed. The material extrusion, an increasingly utilized additive manufacturing (AM) technique, offers a viable alternative to the prevalent laser powder bed fusion (LPBF) methods. This method enables a creation of complex geometries using various materials. The investigation revealed that the horizontal orientation of parts yielded the highest mechanical properties, reaching the ultimate tensile strength of approximately 1200 MPa. Additionally, the material exhibited the hardness of 47 HRC in the as-built state. The conventionally produced steel resulted in the higher UTS and YS in comparison to the AM material. The machinability of the as-built material in regard to cutting forces and surface roughness was also evaluated Lower surface roughness was achieved by decreasing feed per tooth. Optically measure material porosity was 6.13 % with maximum pore size 7.43 µm. The primary objective of this research is to optimize the mechanical properties of H13 tool steel post-printing, with a broader aim to apply the gained insights to improve other materials produced by the material extrusion.

The task of comprehensive machine care, monitoring of reliability and maintenance is currently a priority not to wait for a malfunction, but to prevent malfunctions before they occur. In the possibilities of mod-ern diagnostic tools, this activity is the task of oil analysis, which is a highly effective tool for monitoring the condition of hydraulic oils during their long-term operation. It is possible to prevent the failure of the entire system by regular monitoring of the technical condition of oils based on the analysis of hydraulic oil pollution. Oil analysis can reveal the amount of additive elements, oil pollution, the amount of addi-tives and changes in the physico-chemical parameters of the oil. In order to determine the current state of the oil filling, it is necessary to use a suitable diagnostic method. The submitted contribution de-scribes an experiment aimed at evaluating the state of hydraulic oil by means of EDX (Energy-dispersive X-ray spectroscopy) analysis, DSC (Different Scanning Calorimetry) analysis and infrared spectroscopy.

The paper is a further step in ongoing research on the incorporation of the proposed bulk material rotary valve assembly into an existing production line serving the food industry in bagging milk powder. The main objective of the present paper is the strength static analysis of the previously presented structural design of the trolley and attachment of the frame structure as a track for the travel. Moreover, analytical engineering calculations whose results provide boundary conditions for the numerical strength design of the assembly of the rotary valve for transporting of bulk materials are included in the paper. The pro-posed mechanism allows precise manipulation of the rotary valve, especially at the time when it is nec-essary to clean the pipe connected to the rotary valve. Such manipulation is currently actual because of increasing the safety of maintenance of machines and equipment as well as because of reducing the physical burden of maintenance workers. The results of the analyses demonstrate the suitability of the design and provide a basis for further research in this area. The results discovered will be implemented in the form of additional boundary conditions in the numerical analyses of the frame itself carrying the whole travel of the trolley with the rotary valve (the frame forms the track for the trolley travel). The aim of the research is to reach a condition where the entire structure is safe for the operator during mainte-nance as well as for its surroundings during normal operation.

The purpose of this paper is to study an application of the 35NCD 16 steel by a model generalizing the isotropic and kinematic strain hardening laws. The model in question is represented by a field of strain hardening moduli corresponding to the introduction of the configuration of the flow surfaces. Each flow surface is characterized by its constant elastoplastic modulus, its normal unit vector, its radius and its center coordinates. For cases of uniaxial or multiaxial (complex) loading, in particular for cases of cyclic loading or unloading, the instantaneous configuration can be determined by the position and dimensions of the flow surfaces, determining the strain increment for each strain incre-ment.

By achieving the accuracy and roughness requirements imposed on the connecting surfaces of machine components –the topography created during machining – it is guaranteed to meet the operational requirements. We cannot ignore the fact that if connected milled plane surfaces move in different directions relative to each other during operation, there may be different contact conditions caused by the unevenness of the topography. The direction-dependent roughness irregularities and functional characteristics of the topography are not sufficiently explored, thus in this work we examine the roughness and its deviations by assuming displacements in different directions compared to the feed motion during operation. The inhomogeneity of the topography is analyzed with a symmetrical milling setup on a face-milled surface, with profiles measured in plane sections parallel to and in 8 other different directions from the feed. The degree and distribution of deviations of the recorded roughness profiles, the selected amplitude and functional roughness values are examined at several points of the measurement planes.

The present paper discusses important aspects of residual stress measurements in forged shafts with defects using the X-ray method. A random population of shafts was selected for the study, for which, depending on the type of rolling process, turning was performed, measuring stress changes after successive machining passes. In the forged shafts studied, the existence and location of internal defects were identified using computed tomography. The impact of internal defects on the stress distribution on the surface of the machined workpiece was observed. It was observed that the use of the X-ray method to measure residual stresses makes it possible to determine the state of stresses and their distribution, which is crucial for the safety and durability of shaft-type parts, and allows the impact of a defect on the distribution of residual stresses to be identified. On the basis of the results obtained, it was observed that there is a correlation between the occurrence of internal defects in forged shafts and the distribution of residual stresses in characteristic sections along the length of the shaft after machining

Gears and toothed parts are significant components in power transmission systems. These parts usu-ally manufactured by traditional methods such as machining by milling or forming by rotary forging. In this study, the forming of solid gears or toothed parts using a forging process that combines rotary forging and ballizing technique. The specimens were placed inside the die with excessive volume to fill the toothed part in the die. The forming tool applies pressure to the specimen while rotating it together with the die by the lathe machine chuck, while the tool advances continuously in the direc-tion of the die. This reduces height of the specimen and increases its diameter, causing metal flow to fill die cavity teeth and form the gear or toothed part required for production. Two sets of experi-ments were performed. In the first set, optimization for the appropriate volume of four different sizes of dies and four forming tools was conducted. While in the second set, the effects of forming process variables on the forming load and tooth filling percentage was studied. The results showed that the best tooth filling ratio happened with specimens size of 1.2 to 1.4 times the volume size of the desired tooth for filling. The results also revealed that the forming speed, die size, and forming tool diameter affect the filling ratio and forming load.

This paper deals with the issue of selecting different machining parameters in the CAM system Siemens NX 1946. The issue of choosing between a solid end mill, milling cutter, and a high-feed tool when machining simple rectangular and rugged cavities concerning time and residual material is solved here. The chosen material was 1.1730, which is a basic material for the production of moulds without heat treatment. The paper deals with the issue of choosing the size of tool feed into the cut and its influence on the formation of the machining path depending on the depth of the cavity. The size of the residual material depends on the machining strategy and the choice of the plunge method into the material with regard to the total machining time. Performed simulations and experiments have shown a significant impact in individual settings and, thus, on the cost of machining components of such shapes.

In this study, the process parameters of a vertical shaft impact (VSI) crusher are optimized. Different feed size distributions, material physical properties, and product size distribution requirements are considered to determine the optimal material particle bond cleavage ratio. First, a numerical model is developed to simulate the crushing effect by adopting a CFD-DEM method. Then, the relationship between the crushing effect and the rotor speed, feed size distribution, and feed rate is revealed by analyzing the bond cleavage ratio of smaller-size distribution feed crushing to the specified particle size. The optimized working parameters of the crusher are determined under different feed size distributions. The results show that the feed size distribution of 8 mm, 20 mm, and 40 mm account for 20%, 30%, and 50% of the feed, respectively. Based on the results, it is implied that a feed rate of 120 t/h and a rotor rotational speed of 1800 r/min can be selected for crushing production. When the feed size distribution varies, this method can also be used to select a suitable feed rate and the rotor speed for crushing production. Overall, this study guides for optimizing the working parameters and improving the crushing efficiency.

Hydrogen embrittlement involves the interaction between hydrogen and the microstructure of metals, which can lead to an alarming loss of mechanical properties. For advanced high-strength (AHS) steel S960MC grade, which finds application in fields ranging from heavy machinery to construction, understanding this phenomenon is important. The material's complex crystalline lattice, carefully engineered to maximize strength, becomes vulnerable in the presence of hydrogen. The sources of hydrogen that can lead to embrittlement of steel are various. From the exposure of steel to hydrogen during production processes to the absorption of hydrogen from the environment. After the absorption of hydrogen into the material, hydrogen atoms diffuse in the microstructure and look for places with high stress concentration (cracks, inclusions, grain boundaries, etc.). In these regions, atomic hydrogen disrupts interatomic bonds, weakening the material and making it susceptible to embrittlement and subsequent complete failure of the component. This research is focused on how the change in current density affects the hydrogen embrittlement of AHS steel S960MC during hydrogenation. It was found that the mechanical properties of steel decrease at a lower current density, but not to the same extent as at a higher current density. Thus, it can be said that the change in current density influences the hydrogen embrittlement of S960MC steel.

Methanol, a type of alcohol, with gasoline, a conventional fossil fuel used in internal combustion engines. This blending process is often done to create an alternative fuel that may have certain advantages over using gasoline alone. The combination of methanol and gasoline can offer benefits such as improved combustion efficiency, reduced emissions, and potentially lower overall fuel costs. Methanol has a high-octane rating, which can enhance the combustion characteristics of the fuel mixture. This can lead to more efficient and cleaner combustion in internal combustion engines. Conducting this research is essential to explore potential improvements in fuel efficiency, emission reduction, and overall system performance, which are critical for advancing sustainable energy solutions. The tests were done using a mobile generator Briggs and Stratton ProMax 3500A. The tested fuels were 10 %, 20 % and 50 % blends of methanol in gasoline. The electrical output of the generator was roughly the same for all fuels even at higher load, however consumption increased significantly. The mixtures had a negative effect on the stability of engine operation and engine emissions had a negative effect at most of the measurement points. In some cases, like the concentration of formaldehyde by weight, gasoline fuel mixtures showed a decrease in mass concentration at lower engine loads and an increase at higher loads compared to the reference fuel.

The article is focused on the analysis of the additive technology (3D printing) applicability by using DMLS in the production of the reducing valve part, i.e. atmospheric resistor. Currently, the men-tioned part is produced by EDM in combination with soldering from the Inconel 718 steel. The use of additive technologies brings the assumption of greater flexibility and economy of production, which is verified by a set of analyzes focused on the accuracy of production and the utility properties of the mentioned part. In addition to technological aspects, such as individual production processes, economic aspects are also compared. Individual comparisons are the basis for assessing whether replacing the conventional production approach with 3D printing is advantageous in this case. The results of this assessment can subsequently be used for future applications of the considered additive manufacturing approaches in the case of similar components.

Hydro-viscous drive (HVD) clutch is a type of power transmission device by using shear stress of oil film. Whether the oil film between friction pair are uniformly distributed is the key factor that affecting the perfor-mance of HVD clutch. However, it is hard to make sure that the uniformity of oil film between friction pair are the same, which can lead to uneven wear problem for the frictional plates of HVD clutch. In order to study the uniformity of oil film of HVD clutch, the distribution regularity of oil films between friction pair of HVD clutch is researched by establishing the mathematics model. and a new HVD clutch with double-piston structure is pro-posed, which can greatly improve the uniformity of oil film of HVD clutch.

Today's machining requirements cannot be met without the right tool materials. An ideal universal tool material should combine the highest abrasive wear resistance and hardness with high strength and good toughness, while being chemically inert to the workpiece material. Despite the intensive development of materials sciences the fundamental contradiction between hardness, which guaran-tees resistance to abrasive wear, and toughness, which determines impact and fatigue strength, has not been satisfactorily resolved on a global scale. This paper presents the results of tribological wear testing of commercial cutting inserts of S20S, U10S and CC6090 grades. Chemical composition, den-sity, hardness and tribological wear were determined using the ball on disk method. The analysis of the laboratory tests showed that the S20S, U10S and CC6090 cutting inserts have high resistance to abrasive wear, the loss of total volumetric mass did not exceed 1%.

This paper aims to study the efficiency of using prefabricated layers made from plain cementitious composite materials for enhancing the flexural behavior of reinforced concrete (RC) continuous beams. The strengthening system was applied at 20 mm thickness, 150 mm width, and adequate development length. The prefabricated layers were placed in the tension cover in the positive and negative zones. All beams have the same geometric dimensions and positive and negative steel reinforcement ratios. The results showed that the prefabricated layer was deformed with the RC specimen without debonding, which enhanced the cracking patterns and distributed the crack width. A slight improvement in the strengthened beam capacity was 7% for the yielding load and 6% for the ultimate load. The energy absorption capacity of the strengthened beam decreased by 30.67%, whereas both beams achieved the same ductility index.

Ultrasonic vibration cutting technology for processing difficult-to-cut materials proposed a new machining method to improve the cutting performance, is an effective measure to improve the surface quality and cutting efficiency, widely used in titanium alloys and other difficult-to-cut materials. This paper is based on the development of related technology research at home and abroad, first from one-dimensional ultrasonic vibration cutting, two-dimensional ultrasonic vibration cutting, three-dimensional ultrasonic vibration cutting three dimensions to high-speed ultrasonic vibration cutting to carry out the analysis, and then from each dimension of turning, drilling, grinding and milling and other different ways of cutting mechanism, cutting force, surface quality, device development, tool design and other directions of the systematic analysis and research. The analysis results show that ultrasonic vibration cutting technology provides new technical solutions and methods to solve the problems of low efficiency and low dimensional accuracy in processing difficult-to-cut materials by ordinary cutting technology, and can provide technical support for the processing of difficult-to-cut materials. Finally, it looks forward to the future trend of ultrasonic vibration cutting technology: in the future, the integration with five-axis machining technology, additive manufacturing technology, microscopic inspection technology, 5G communication technology and other cutting-edge technologies will be the development direction of ultrasonic vibration cutting technology.

Flexible strain sensors show great potential in the field of wearables and health monitoring. However, the application of traditional strain sensors on flexible substrates is still limited, and the development of sensors with high sensitivity, excellent stability and good durability is a current research focus. Aiming at the limitation of traditional strain sensor in flexible materials, a flexible strain sensor based on Kirigami structure is proposed. In this study, a Metallized Polyurethane Conductive Sponge (MPCS) was used as the sensor substrate. In the preparation process, we used laser direct writing process to achieve the preparation of highly accurate, patterned sensitive structures. In addition, the length parameter of rectangular hollow structure is optimized by finite element analysis to improve the stability of the sensor. The experimental data show that the prepared flexible strain sensor has a high strain range (130%), a maximum sensitivity of (GF=1.184), a response/recovery time of 168/186 ms, a good linearity, and a very good repeatability and stability during 2000 working cycles.The preparation method provides an effective means for realizing high-performance flexible thin film sensors, and has broad application prospects in intelligent wearable devices, human-computer interaction, health monitoring and other fields.

This paper proposes a solution not previously used in the forging industry, which aims to reduce the proportion of arduous human labour. The concept of a prototype robotic station for hot forging includes a system that allows the selection of batch material with its heating, the execution of the process of lu-brication of forging tools and the forging itself, synchronised with the feeding and removal of material using full automation, in accordance with the idea of Industry 4.0. At the same time, by increasing the repeatability of the entire forging process and changing some of its key parameters, it will be possible to influence the durability of the tools used during its implementation. In order to verify the impact of such a modified technological process on forging tool life, computer simulations of forging were performed, where the currently applied technology using hand forging was compared with a conceptual automated process.

This paper provides an overview of the commonly used processes and equipment for laser cladding, including pre-set powder feeding, simultaneous powder feeding, wire feeding cladding, and coaxial cladding nozzles. By comparing the above processes and related nozzles, the coating characteristics are summarized for the selection of appropriate methods and equipment in different working environments. Meanwhile, the morphology and properties of the clad layers of shaft parts processed with different process parameters (e.g. laser power, scanning speed, lap rate, powder feed rate) and the influence of the combined parameters are overviewed. The changes and mechanisms of metals, ceramics, and metal-ceramic composites in terms of hardness, wear resistance, metallurgical bonding, and microstructure are analyzed. In addition, the application of numerical simulation techniques to simulate the temperature and stress fields and to plan the melting trajectory when laser cladding processing is performed on the surface of shaft parts are reviewed. Finally, the problems in the current research on laser cladding of shaft parts are summarized and the development directions are discussed.

The aim of this study was to verify the laser shock peening (LSP) on the microstructure of P265GH steel and X6CrNiTi18-10 stainless steel. The LSP surface treatment was done underwater on the dis-similar weld joint of the P265GH and X6CrNiTi18-10 tubes. The metallographic analysis then focuses on the evaluation of microstructure in heat-affected zones of both materials. The results of our analysis are possibly summarised as follows. Light and scanning electron microscopy have shown grain refinement in the treated surface of the HAZ region of X6CrNiTi18-10 steel. For P265GH steel, it was possible to find a remelted surface layer with a thickness of 3.3±0.6 micrometers in the peened areas. For P265GH steel was also possible to observe a significant increase in dislocation density in the grains with straight contact with the peened surface. In the case of X6CrNiTi18-10 steel, this area extended to a depth of over 50 micrometers from the peened surface.

In order to improve the crushing effect of the rotor of vertical shaft impact crusher on the particle, the design method of secondary accelerated rotor based on kinematics theory is proposed. And the operation effect of the secondary acceleration type rotor was verified using a combination of computational fluid dynamics and discrete element method (CFD-EDM). First, the kinematics of the particles thrown by the rotor throwing head was analyzed. On this basis, the structure of the secondary acceleration type rotor was designed by comprehensively considering factors such as the motion, friction, and collision recovery coefficient of particles; Then, based on the gas-solid coupling analysis method, a simulation model of the rotor's effect on particle acceleration was established and the reliability of the model was verified; Finally, the CFD-EDM method was used to calculate and analyze the motion process of particles in the crushing chamber, the collision position of particles in the crushing chamber, and the average throwing speed of the rotor. Research results show that roughly 77.6% of the particles in the crushing chamber will collide with the impact plate to achieve secondary acceleration; The average throwing speed of the traditional rotor is 57.14m/s, and the average throwing speed of the designed secondary accelerated rotor is 60.89m/s, which is about 6% higher than the average throwing speed compared with the traditional rotor, and achieves the expected design purpose.

This article explores the effect of cryogenic temperatures on the properties of cobalt alloys, specifically Stellite 6 and Stellite 12. These alloys are commonly used in applications that require resistance to me-chanical, thermal, and chemical wear. In this study, the focus is on the valve seats for internal combus-tion engines, which are made from cobalt alloys and undergo a freezing process before assembly into the cylinder head. The purpose of freezing is to reduce the diameter of valve seats, making them easier to fit into the cylinder head. However, the length of time spent in freezing can significantly affect the hardness and tribological characteristics of the material.

Manufacturing inaccuracies in vehicle suspension systems inevitably lead to uncertainties in the parameters of their structural components. Simultaneously, the road excitation impacting nonlinear vehicle systems exhibits pronounced randomness and time-variant characteristics. Consequently, it is crucial to conduct a stochastic dynamics analysis on nonlinear suspension systems, taking into account these uncertain factors. In this paper, a seven-degree-of-freedom (7-DOF) nonlinear suspension system dynamics model has been established. The stochastic process of road irregularities is simulated using the harmonic superposition method. Moreover, based on the direct probability density integral method, the stochastic dynamic equations of the nonlinear suspension system and their corresponding solution strategies have been developed and explored. Through MATLAB, the time-varying probability density function of the vibration response for a nonlinear vehicle suspension system was calculated under the combined effects of stochastic road irregularity excitation and random coupling of system structural parameters. Additionally, analyses were conducted on how different coefficients of variation and the intensity of nonlinearity in the suspension system influence the probability density of the output body displacement of the nonlinear vehicle suspension system. The research outcomes demonstrate that the direct probability density integral method offers superior efficiency and accuracy when computing nonlinear vehicle suspension systems. Furthermore, altering the coefficients of variation for various system parameters reveals that as these coefficients increase, the disparity in the probability density of body displacement becomes more pronounced, leading to more intense vehicle vibrations. Under soft nonlinear conditions with lower suspension spring stiffness, the probability density function of body displacement shifts slightly to the right with minimal change. However, under strong nonlinear conditions, body displacement significantly increases, resulting in diminished vibration isolation capabilities of the suspension system. This leads to severe jolts and a noticeable decline in ride comfort during vehicle operation.

The paper focuses on proposing a method for implementing key performance indicators (KPIs) to assess the effectiveness of manufacturing processes. For the evaluated processes of precision parts machining, the share of non-conforming products was proposed as a KPI, evaluated as both an exter-nal and an internal indicator. The external indicator EXTppm expressed the quantity of faulty prod-ucts to the volume of production. Its monthly development during 2022 was evaluated. The internal KPI represented the internal share of non-conforming products INTppm during 2022 which was re-lated to the order of part A. Towards the conclusion causes for not attaining the targeted KPI values are pinpointed, and recommendations are put forth to enhance the productivity of manufacturing processes.