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The article deals with the possibility of increasing mechanical and utility properties by means of regenerative heat treatment. Experimental program is focused on the heat treatment of low-alloy heat-resistant steel EN ISO 14MoV6-3. This steel has been used since the 1970s for high-temperature exposed components in practically all coal-fired thermal power plants in the Czech Republic. Thus, steel EN ISO 14MoV6-3 is currently the best studied refractory material whose data, collected from experimental creep behaviour tests, exceeds the computational service time 2.105 hours. In order to remain competitive in the new energy mix, conventional steam power plants are forced to adapt to the requirements of semi-scheduled power generation. However, these plants were not originally designed for such operation and therefore have to adapt to new demands on the timing of the power provided, including requirements to reduce overall plant emissions and to increase the efficiency of power generation. These components are now subjected to substantially increased cyclic stresses due to power changes during half-cap operation. These stresses have a major impact on the material lifetime and therefore on the overall performance and lifetime of the plant.

The aim of this work is to propose a methodology for evaluating inhomogeneity due to the sedimenta-tion of fibres in High-Performnce Concrete (HPC) mixtures. HPC mixtures makes better mechanical-physical properties than ordinary concrete. To achieve higher strengths, the fine-grained matrix is rein-forced with the reinforcement – fibres. The type of used fibres and their homogenization in mixture has an influence on the final mechanical properties of HPC mixture. Four concrete mixtures with same com-ponent proportion was chosen for experiments. Water was the only one component, that was changing in mixture recipes. Steel fibres with a ratio of the diameter to length = 0.3/20 were used as reinforcement. The fibre volume in mixture was 1.5 %. The microscopy analysis was used for evaluation of the fibre dis-tribution in the test specimens. It was obtained, that the concentration of the fibres increases with dis-tance from the surface to the bottom of the HPC structure and this non-homogeneity increases with higher water dosage. The dependence of sedimentation of fibres on composition of HPC mixtures can be used for evaluation and optimization of final mechanical properties of the HPC structures.

This study focuses on the analysis and solution of thread production in thin-walled profiles. It explores three different threading technologies, including cutting, forming, and extrusion. The issue of a screw joint in a thin-walled component is complex due to the stiffness of the joint and the short length of the thread. Hence, the careful choice of a suitable manufacturing process for producing inner threads in thin-walled components holds significant importance. The study entails monitoring the hardening of surface layers of materials after thread production, in conjunction with the acquisition of microstructure images of the experimental material. The outcome is a comparative evaluation of different individual thread production technologies.

The aim of this article is to approach the measurement of forces and pressures of collaborative robots. In the article, research will be carried out on measuring the forces and pressures of a collaborative robot before putting it into real application. Force and pressure values will be measured using appropriate measuring devices. The measured results will be compared with the ISO/TS 15066:2016 technical specifi-cation and subsequently evaluated.

Aiming to study the influence of ultra-precision grinding parameters on the accuracy between the same clamping method and different workpiece sizes. This paper mainly analyzes the difference between the measurement precision of different parts by the same measurement method and the measurement precision of the same parts by different measurement methods. Therefore, the influence of grinding parameters on grinding precision is reflected. For the same part, it is concluded that the coaxiality error coincidence degree at end A and end B reaches 90.32% and 95.27%, respectively by using precision three-coordinate measuring instrument and Mahr roundness instrument. The coincidence degree of end A and end B verticality error reached 97.54% and 91.08%, respectively. For parts with different sizes, the Mahr roundness meter is used for measurement. The analysis shows that the coaxiality coincidence at end A and end B is the highest, reaching 98.36% and 92%, respectively. And from the analysis, the errors are mainly reflected in the factors such as jig and fixture and grinding process.

A modern user requires low operating costs, but also reliability from machines and technical devices. Reliability during the service life depends on the quality of construction solutions, but also largely on the quality, properties and adaptation to the working conditions used in the construction of construction materials. During the operation of technical objects, their a highly predictable wear occurs. The problem is the phenomena of premature wear and damage of elements. The causes of failure of technical facilities are usually complex and depend on many factors. They can include the human factor and the one related to the quality, selection, production and technological processes of the materials used in the construc-tion of the facility. In real technical facilities, many premature failures are caused by material fatigue, which is related to the quality and distribution of impurities in the material. The paper presents the change in fatigue strength for rotational bending of low-carbon structural steel hardened and tempered at different temperatures as the effect of the size and distance between impurities on the fatigue strength of high-quality carbon structural steel melted in the industrial conditions in an electric arc furnace.

The article deals with a possibilities of an enhancement of functional properties of highly stressed components by specific combination of surface technology. Two surface technologies such as plasma nitriding and laser shock peening were selected for the experiment. Those technologies were applied upon steel 42CrMo4 frequently utilized in manufacturing of strained components. Properties obtained by applied surface technologies were tested by following experimental methods. The chemical composition was verified by optical emission spectrometer Tasman Q4 Bruker. The surface morphology was inspected by scanning electron microscope TESCAN MIRA 4. The microstructure of heat treated as well as of nitrided specimens was observed by opto-digital microscope Olympus DSX500i. The microhardness profiles were measured by microhardness tester LM247 AT LECO. The friction coefficient was tested on tribometer Bruker UMT 3 TriboLab. For an assessment of the surface wear resistance the profilometer Talysurf CLI 1000 and Contour GT were utilized. The experimental results show that although the proposed surface technology combination manifests itself to be disadvantageous, both technology LSP, as well as plasma nitriding, applied separately, can lead to a significant wear reduction.

In this paper, the adhesive behaviour of different polyurethane glues was studied and compared. The study was inspired by real conditions in the production of car windows, and it is divided into several parts, which deal with three types of polyurethane adhesives. The first type is a standard one-component polyurethane adhesive, which cures with air humidity. The second type is a one-component polyurethane adhesive with the addition of a curing accelerator. And the third type is a two-component polyurethane adhesive. Adhesive blocks of defined dimensions and plastic parts glued to the glass were used for this experiment to simulate a real product. The influence of temperature and humidity on the curing process was evaluated. The test included measuring the force required to tear the parts from the glass and assessing the type of failure. Based on the achieved results, the adhesives were evaluated regarding their applicability in the real automotive industry and the key properties necessary to maintain the safety and quality of the glued part were determined

Thin sheets of aluminum alloys are widely used for the packaging of pharmaceutical and cosmetic products and in the food industry; however they present critical issues during the forming process. The blow forming process, which is widely used in the glass and plastics industries and for the hot forming of metal sheets, allows solving the problems related to the lubrication and the small tolerance ranges of the tools required by the well-known deep drawing process to form a thin sheet. In this work, the blow forming process is proposed for the first time to cold form thin metal sheets. Its advantage is connected with the use of equipment with a simple shape and, therefore, less expensive. Specifically, this work evaluates the time needed to form a simplified part; this is a critical aspect to apply this forming process to the food packaging industry. Moreover, this process represents the first step to developing a method-ology for evaluating the constitutive equation of thin sheets as an alternative to tensile test that has some critical issues connected with specimens’ manufacturing and test carrying out.

According to the application requirements of SOC in lithium batteries of Unmanned Aerial Vehicle (UAV), an Extended Kalman filter-Double Kalman filter (EKF-DKF) composite model was proposed to optimize the accuracy of the last 20% stage of State of Charge(SOC) estimation. Based on the equivalent model of second-order resistance-capacitance (RC) circuit improvement, the developed method optimized the identification accuracy of parameters, and set up a MATLAB simulation platform to jointly estimate SOC online with EKF and DKF. The data obtained in laboratory test environment were used for simulation.

The growing use of composite materials in various industries implies the necessity of conducting research on both their manufacture and subsequent machining. One of the main problems in composite machining is the selection of a suitable cutting tool. This study investigates the effect of the geometry and material of a milling cutter on the quality of a milled composite part. A carbon fiber-reinforced epoxy resin matrix composite was tested. Two cutting tools were used: an end mill with PCD inserts with a diameter of 12 mm and the number of teeth of 3 as well as a PCD-coated carbide end mill with a diameter of 12 mm and the number of teeth of 4. Variable technological parameters were used. The quality of the machined surfaces was assessed based on burr height and selected profile roughness parameters. Results showed that for the milling process conducted with the same technological parameters, the surface quality obtained with the 4-tooth PCD-coated carbide tool was higher than that obtained with the 3-tooth tool with PCD inserts.

The condition for the designability and efficiency of the machining processes is that the part production process is chosen to meet the operational requirements based on the most accurate technological plans possible. One part of this is the planning of the required quality and roughness of the surfaces and achievement of the required values in the finishing. In this paper, a study on the predictability of surface roughness was performed using a CAD model based on theoretical roughness and validated by cutting experiments. The reported results show the effect of the feed rate change in face milling for two tools with different edge geometries in planes parallel to the feed direction.

Joining technologies are very important aspects of production process in the automotive. Especially regarding the use of newly developed types of materials (e.g. ultra high-strength steels or aluminium alloys), in addition to welding technology, e.g. riveting or adhesive bonding technologies are used. Submitted article evaluates the effect of the riveting force on the final quality of riveted joint when joining aluminium alloy EN AW-6016 (thickness 2 mm). The actual evaluation of the riveted joint was carried out using a shear test, measuring the hardness HV01 and deformation analysis of specimen using non-contact optical scanning (ATOS III Triple Scan system).

Traditional assembly sequence solving methods often face problems such as combinatorial explosion and low efficiency in solving complex products with multiple parts. To improve the level of assembly sequence planning (ASP), an interference matrix is established to express the basic assembly information of a product. Taking the stability of the assembly sequence, the number of assembly direction changes, and the number of assembly tool changes as evaluation indicators, a fitness function is constructed. An improved particle swarm optimization (IPSO) approach for ASP is developed based on the peculiarities of the ASP issue. Redefining particle positions, velocities, and their update operations, and introducing mutation operators in genetic algorithm (GA) to improve the ability of PSO algorithms to jump out of local optima. Furthermore, the algorithm's convergence speed is enhanced by adjusting the value of the inertia weight. Finally, an example is provided to demonstrate the IPSO algorithm's usefulness and efficiency.

The subject of research is the kinematic parameters of a biplanetary mechanism of the intermitted mixing machines. The article substantiates analytical expressions for determining the kinematic parameters of the drives of the working body of the intermitted mixing machines with planetary ones with double satellites and biplanetary mechanisms; the laws of change of displacements, velocities and accelerations of the points of the working body for drives with planetary one with double satellites and biplanetary mechanisms are determined; the regularities of the influence of the velocity parameters of the driving links on the kinematic characteristics of these mechanisms are established.

New energy vehicles driven by electric motors have higher requirements for the lightweight and high reliability of their gear transmission devices. It is now necessary to optimize the precision forming process of their structural gears. The integrated structure gear without undercut produced by precision forming technology can reduce axial size while improving the strength and reliability of gear parts. Based on the performance requirements of integrated structural gear parts in practical applications, a process plan of "hot forging forming +cold trimming tooth shape" was developed, and compared with existing hot extrusion forming plans. Simulation analysis was conducted on the hot forging forming process of integrated structural gears. Through the improvement and optimization of the process plan, the extrusion stress during the filling process of the formed gear teeth was reduced by about 29%, achieving a good forming effect, in order to provide data reference for the forming of this type of gear.

The paper presents the results of an experimental work on the assessment of microscopic morphology of the surfaces obtained as a result of cutting with a Water Jet (WJ) water abrasive beam. The examination of microscopic structures was carried out with the use of Nova NanoSem 450 scanning electron micro-scope. The subject of analysis were the interfacial structures of multilayer structures connected in a vul-canization process with the surface of thin-walled parts made of AW-5754 aluminum alloy. The results of the research were compiled as a function of the technological WJ cutting conditions, such as feedrate and abrasive material flow.

Main goal of this study is to describe and design manufacturing system which is using Additive manufacturing technology for production of semi-finished products and conventional machining technology for finishing operations, then demonstrate requirements of such production on simulation model on production planning and then analyze and summarize the outputs of the production model. The model is made with aid of modern Digital Factory tools. The main purpose of the model is to provide a complex tool for this study in order to analyze and optimize the fictive production system in needed range and complexity. The topic of Rapid Prototyping and Additive manufacturing technologies is very recent topic in industry. But still, there are only few examples of production systems, which are really using Rapid Prototyping technologies as a part of the production or production line. The advantage of these technologies is their versatility, but on the other hand, as a part of production system, they can have different demands on for example production planning, area consumption or maintenance, that can affect whole production system.

The traditional Mixed-model Assembly Lines (MMALS) balancing and sequencing serial design methods are difficult to adapt to rapidly changing requirements. From the perspective of the parallel design of balancing and sequencing, a mixed integer linear programming model for MMALS balancing and sequencing is proposed. An improved particle swarm optimization (PSO) algo-rithm was proposed, in the process of updating the optimal solution, the simulated annealing (SA) algorithm is added to make it possible to jump out of the local optimum with a certain probability and expand the solution selection to the entire population. Based on the algorithm, random coding and ascending decoding methods are proposed, the number of products and the number of tasks are coded and decoded at the same time. Verify the effectiveness of the algorithm by an example.

This paper presents some advanced techniques on CAD modelling and CAM programming for 5-axis machining of free-form surfaces. In the CAD stage, based on surface partitioning, the design surface can be created with separate regions such as convex, concave and saddle. Point-based techniques are used to create the original surface and the boundary curves of the regions. Some other CAD/CAM techniques for determining tool sizes and tool orientations are also proposed to generate gouge-free tool paths for each region. A simple B-spline surface was given as an example to demonstrate the proposed techniques implemented in Creo Parametric. The points on the design surface and on the boundaries were generated by a Matlab program developed by the author.

Tubes of super-heaters and heaters used in conventional power plants are exposed to coolant and high temperatures. The growing oxide layer on the inner surface reacts over time as a heat insulator on the water side and reduces heat transfer through the wall of the tube. A relatively thin oxide layer already contributes to the boiler efficiency and causes a permanent overheating of the tube wall. As a result of overheating at the site, the intercrystalline cracks leading to the bursting of the tube are developing. The secondary problem of the growth of oxide layer thickness is so-called exfoliation. For non-destructive evaluation of the thickness of the oxide layer directly at the power station, ultrasonic method (UT) can be used with a high frequency probe. In order to verify the accuracy of the measurement and the qualification of the ultrasonic testing methodology, light and Scanning Electron Microscopy (SEM) was used on specimens that were removed from the super-heater after the UT measurement. The standard longitudinal cut surface imaging in BackScatter Electrons (BSE) and Energy Dispersive Spectroscopy (EDS) analysis for accurate thickness determination with the chemical composition of the layer confirmed the accuracy of the UT measurement.

This paper presents the theoretical and practical aspects of industrial robots transport systems problems focused on application possibilities connected with concrete type of robotic device. Introduction of the article presents today possibility of robot transport systems and collect information about basic technical parameters of transport systems, their design and construction. Main part describe industrial robot ABB IRB 140, collect information about technical parameters, its construction, axes, motions and applications used in industrial practice. Practical part of paper is focused on proposal of robot transport system design from manufacturing point of view.

Vibrational properties of road vehicile are ussually evaluated according to two criterions, i. e. in terms of comfort for passengers and in terms of drive safety and roadway load. The topic of this article is focused on evaluation of passenger's ride comfort of a three-wheeled road vehicle. From the ride comfort point of view vertical vibration is decisive. Vertical vibration is given by obtained accelerations in given position on an assessed vehicle when it is driving on a road with various surface qualities within required time intervals. In the vehicle's design phase its vibrational properties are detected and evaluated by means of simulation computations on a virtual model. In our research we have assessed ride comfort of the three-wheeled vehicle, which were designed in our workplace. For purposes of dynamic analyses we have used multibody approach using Simpack software. The objective of this work is verification of the relevance of the current mounted suspension system for the greater driving speeds range of the three-wheeled vehicle and for different road qualities.

The paper puts forward structure design and parameter analysis of the multi-angle and stepping transmission device, and this paper focuses on design and analysis of the multi-angle steering parts in the device. According to mathematical calculation and simulation analysis, the parts size of steering component is simulated and designed by the double cam-linkage mechanism. Though the design of these critical components of the steering device, the rods can be rotated in the specified angle (45° and 90°) by their relative motion without any external force, and the steering device is simulated by SolidWorks Motion. The results show that the multi-angle and stepping transmission device realizes the upset forging process requirements, improves the mechanization level of the sucker rod forging. The device will be used for the rod head machining operation in narrow space in automatic production line, and it also can be extended to other cylindrical rod's multi-angle and multi-position automatic machining operation.

Aluminium roofing is used for low weight, good strength and weather resistance, easy handling and assembly, for various roofs of industrial and agricultural buildings, residential and family houses, holiday homes, garages and various shelters. Important is very long life, relatively low price and the possibility to choose the colour design according to your taste. The basic form is a natural unpainted finish, which can be used because the aluminium roofing material is not subject to corrosion and is chemically stable. The aim of this research is to verify a suitable method of measuring the colour of aluminium roofing and to determine the basic characteristic values of the most common colours of aluminium roofing sheets. The identification by the CIELAB system makes it possible to characterize the suitability of roofing sheets in terms of reducing the heat gains of the roof structure, thus complementing this very practical information to the RAL colour marking system. This leads to a reduction of the cooling demand of air of the building in the summer. In terms of colour measurement and evaluation, the classical method according to the CIELAB system is where the colour attributes lightness (L-value), redness (a-value) and yellowness (b-value). These values may include the effect of surface gloss (SCI values) or exclusion (SCE values).

The goal of the proposed methodology is to manage and evaluate investments across the portfolio of projects in the company, with extra focus on selecting engineering projects into the portfolio. In order to design an objective methodology, several analyses were conducted to verify a general validity of the methodology. The starting point is using methods which allow a high degree of flexibility in solving problems. The ANP method is suitable for the determination of priorities in network systems with different types of dependencies between the elements of the system. The DEMATEL method is used in this methodology to formulate the structure of relationships between the criteria of the system and obtain the criteria importance in the system. All calculations were carried out using the MAXIMA and Super Decisions software. The proposed methodology has been verified on a case study using real-life data supplied by the participating company. There were used methods of decision making, especially methods of operations research, linear programming and team expert selection methods.

Additive technologies are a dynamically evolving category of manufacturing methods for a wide range of industries, particularly engineering and related fields. Compared to traditional technologies based on chip machining, molding and casting, they offer new production options, particularly for complex shape components. At the same time, however, there are differences and limits that must be taken into account when designing functional machine parts. The important quality parameters of the products are in particular the dimensions and the quality of the surface. These factors are of fundamental importance for the subsequent assembly and function of a component in a plant assembly. They determine, together with the structural material properties, the usability of the component and the economic efficiency of the production in order to achieve the finished product with the minimum need for postprocessing the finished part. The submited text presents the results of the quality parameter research carried out on 3D print products made by the DMLS method, where the focus is put on the assessment of linear dimensions and the surface quality of samples from three selected materials and a combination of two print modifications. The measurement results are compared to generally valid standards and tabulated values to verify and eventually modify table values for use when designing a design solution with the use of 3D print products.

This paper presents a development and design of new multifunctional clamping jaws for thermomechanical simulator. In the article there is presented what the thermomechanical simulator is and what is it used for. The article also describes the requirements for the thermomechanical simulator jaws and how they were achieved. All important parts of which the thermomechanical simulator jaws are assembled and used are described in detail. Finally, thermal simulations of the jaws were performed under operating loads. This technical solution is protected as a utility model registered on The Industrial Property Office - Czech Republic.

The paper deals with a design of new dimple geometry with a view to minimizing its thinning. In this case, three types of blank materials were analyzed, i.e. ferritic steel X2CrCuTi18, austenitic steel X5CrNi18-10 and austenitic steel X5CrNi18-10 with additional heat treatment. Thinning analysis for different dimple geometry and blank material is performed with a numerical simulation using finite element method in ANSYS software. To verify the accuracy of the numerical simulation, a practical stamping of the part with initial design and comparison between resulting thinning values, which is determined by ANSYS software and experimental microscopic measurement, is also performed.

Based on analysis of joint dynamic characteristics to obtain dynamic values of combined surface incorporating joint dynamic data, a method for dynamics modeling of machine tool considering joint dynamic characteristics is developed and analyzed. The machine tool is simplified and modeled by selecting the motion coordinates of each component in accordance with the structure characteristics and the vibration displacement for each component in exciting test. According to the way and condition of the joints, the equivalent dynamic parameters of each joint are determined by applying the general joint surface dynamic data. Calculation methods of dynamic parameters for some typical joints in machine tool structures are analyzed and described. Taking a horizontal milling machine as an example, the machine is simplified into a dynamic model with 21 degrees of freedom, the calculated results of dynamic characteristics correspond to that of exciting test and modal analysis. The modeling method is effective and applicable in machine tool design and structure improvement.