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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.

Increasing the efficiency of cutting operations while fulfilling the required (expected) quality of the parts constantly requires a thorough knowledge of the chip removal process. This is especially justi-fied in the case of deviations from the usual (traditional) technological conditions or cutting data, both in terms of cutting theory and technique. This paper summarizes some of the results of a study of cutting force and cutting temperature in face milling. The technological analysis of face milling was performed by FEM simulation, which was compared and validated by measuring the cutting force. The chip removal of C45 rolled steel as a function of tool rotation was studied with two differ-ent depths of cut ap and feed rate fz so that at a constant nominal Ac cross section the ratios ap/fz were 0.1 and 10. The effect of the change of the cross-section and chip ratio is shown.

This article describes problems of porosity which are caused after welding of aluminium alloys. The main part of this article is dedicated of methods of correction of porosities. The best correction is by welding or by cementation. Described parts are used for welded aluminous vehicle parts in a cooperative company. Thanks to porosity are effected not only ductility and strength of welded structures but also weld quality thereby fall also resulting in surface treatment. Cooperative company is ranked among the world's leaders in development and production automatic, electro-pneumatic and electrically operated door systems for rail vehicles and traffic island as ramps, plateaux 'sand stairs. Staffs of this company have years' experience in the area of welding rail vehicle parts from aluminous alloys. A company has a certificate on welding rail vehicles and their compo-nents according to standards EN ISO 15085- 2. For public transport company produce sliding doors, driving and inner and among - wagon doors. The same types of doors offer for long-distance transportation and also for high-speed trains. Further, they produce traffic islands, for example, extensible ramp, extensible plat-eaux, foldaway climbs and bridging, everything is produced from aluminous alloys.

The results of researches on porosity and structure of castings from AlMg9, AlSi7Mg and AlCu4Ti alloys produced by squeeze casting and for comparison by gravity die casting are presented. The tests were carried out on 200x100x25mm plates squeeze casted under 90MPa pressure. Prior to the commencement of experimental studies, numerical simulations of solidification were made for the selected alloy (AlSi7Mg) in order to determine the potential locations of shrinkage porosity. As part of the study, the porosity distribution in the plate cast was assessed by taking samples for measurements from the center and edge of the casting. It was found that the area particularly vulnerable to the presence of shrinkage porosity is the central part of the casting and the zone extending from its center to the upper surface. Due to the wide temperature range of solidification of the examined alloys, diffused porosity occurs in castings, and the shape of the pores formed is conditioned on the solidification morphology. The average porosity of squeeze castings is two times smaller than gravity die castings and is at the level of 1.0-1.5% depending on the type of alloy. In addition, as a result of pressing, the shrinkage porosity in the central part of the plate is reduced and its distribution becomes uniform throughout the volume. High pressure acting on solidifying castings ensures a significant increase of grains density in microstructure and decrease of SDAS.

This paper investigates the replacement of a conventional steel coil spring with a composite disc spring with the aim of minimizing its weight. Simulation in the CAD system Siemens NX 12 was used to determine the composite disc spring’s behavior. The regression functions were stated based on the numerical simulation. Based on the regression functions the solution with the minimum weight was found using software programmed in Matlab. The prototype discs were manufactured from carbon fibre prepreg. Their load-deflection characteristics were tested and compared with the designed values. The experimental results show that using this solution reduces the weight by about 30% in this case.

Taking a brake drum as the research object, the dynamic characteristics analysis and optimization designare carried out by using the finite element method.In order to increase the stiffness without increasing weight of brake drum, the main design parameters were tested by Box-Behnken experiment design. The three-dimensional model of brake drum was established by using SolidWorks software, then the finite element model of brake drumwasobtainedby imported into ANSYS software and its modal analysis was carried out. On the basis of modal analysis, the three important dimensions of brake drum were defined as input parameters, the drum weight, the first, second and third natural frequencies are defined as output parameters. The response surface model between the input and output parameters was established by using DOE (Design of Experiment). Finally, the input parameters were optimized by multiobjective genetic algorithmand the fivePareto solutionswas obtained. The fifth solution was chosen as the optimal solutionbased on the production technique.The weight of brake drum was not changed obviously after optimization, but the first, second and thirdnatural frequencies were increased by13.07 %, 8.92 % and12.73 %respectively, which provided a new idea for the design and optimization for brake drum.

The present contribution examines the structures of and corrosion processes in copper-basalt composite laser claddings on a steel substrate. The cladding material was a laboratory mixture of the following components: Oerlikon METCO 55 (Cu > 99.9 %) + basalt dust. In this investigation, metallographic structures of copper-basalt composite laser claddings were studied using optical and scanning electron microscopy. The adhesion of the claddings to the substrate was testing using the non-standardized Mercedes test. A potentiodynamic corrosion test in artificial mine water was performed on a specimen of the composite laser cladding. The test results were compared against those for a reference high-purity copper standard and AISI 304 steel. The findings were interpreted in terms of the potential of using copper-basalt composite laser claddings as corrosion protection coatings on steel components in nuclear power generation.

Materials for parts which are subjected to abrasive wear in service are typically selected on the basis of the microstructure type and hardness. Additional characteristics, such as grain size and the size and morphology of carbides are considered less frequently, although they may prove very important. This article deals with treatment cycles which combine an unconventional forming technique and subsequent heat treatment and explores its impact on abrasive wear resistance in X210Cr12 tool steel. Effects of microstructure refinement prior to and during forming and during heat treatment are described. The forming cycle involved semi-solid processing and was followed by quenching. This sequence refined the initial microstructure and altered the morphology of chromium carbides. The semi-finished products were then cryogenically treated at 160°C for 24 hours and in some cases, subsequently tempered at 300°C for 2 hours. Their wear resistance was tested by blasting and the relationship between the treatment and the weight loss in the test was assessed.

Technological progress in the 21st century has catalysed the industrial revolution (Industry 4.0) following the development of multiple new industrial automation technologies in the manufacturing sector. Regardless, past research indicated the unsuccessful attempts in adopting Industry 4.0 technologies among manufacturing organisations. Undoubtedly, the operationalisation of Industry 4.0 in manufacturing proved challenging as organisations were required to evaluate various aspects for effective implementation. Thus, a sound understanding of constructs concerning employees’ acceptance and readiness levels towards novel automation technologies was required. Hence, this study aims to explore, develop, and validate the suggested conceptual framework by integrating the Technology Acceptance Model (TAM) and Technology Readiness Index (TRI) with Exploratory Factor Analysis (EFA). The EFA process was the first crucial step in ensuring the internal consistency and stability of the instrument across the sampling population. Consequently, the research outcome potentially enabled the manufacturing sector to identify and comprehend the key determinants in designing industrial automation technologies. This study also contributed to knowledge on technology acceptance by synthesizing TAM 3 and TRI 2.0 theories, thus constructing a new TAM in manufacturing.

The article describes problems of welding heterogeneous welds be specific of heat resistant steel X15CrNiSi20-25 with cobalt alloy Stellite 6. Heterogeneous welds are produced by GTAW (141 according to standard EN ISO 4063) welding method. The major goals of the experiment were performing preliminary welding specifications (pWPS) for a specific welded part. Further was necessary for this weldment set parameters on mechanical testing.

Low carbon low alloyed high strength steel with the chemical composition suitably designed to support the stabilization of retained austenite was used in this work. The steel was processed by conventional annealing for a reference and several different heat and thermo-mechanical treatments were further proposed to test typical TRIP (transformation induced plasticity), DP (dual phase) steel and QP (quenching and partitioning) processing routes. All the processing methods used the same soaking temperature of 1050 °C. Processed samples were subjected to metallographic analysis, hardness measurement and tensile test to characterise resulting microstructures. While simple annealing reached tensile strength of 861 MPa with 25% of total elongation, the best combination of the highest tensile strength of 903 MPa and total elongation of 32% was obtained after processing typical for TRIP steel. QP treatment resulted in the highest tensile strength of 1289 MPa with a total elongation of 19%.

The production of automotive products from polymeric materials represents operations associated with the flow of material during its shaping to the desired final mold. The technological aspects of the processing of polymeric materials are closely related to the rheological properties. The article deals with adding technological waste from production to virgin material and its influence on rheological or flow properties of selected polymer composite. The analyzed material is used in the manufacture of components (connectors) in the automotive industry. The rheological properties were measured in two stages. In the first stage, rheological properties were assessed in the short term immediately after preparation of the test samples. In the second stage, half of the samples were exposed to elevated temperature and the effect of aging on the rheological properties of the material was monitored. Based on measured MVR values before exposure to elevated temperature, it can be said that the amount of process waste does not significantly affect the flow properties of the polymer. After exposure to elevated temperature, there is a significant decrease in polymer flow properties probably due to the crystallization of the macromolecular chain.

The paper deals with the change in carbide grain size of sintered WC-Co carbide after cryogenic pro-cessing. Because this structural parameter has a significant effect on mechanical properties. Some sources indicate that due to cryogenic processing takes place to reduce the size of carbide grains and other sources indicate that takes place to increase the size of carbide grains. Measurement of the grain size can be performed using several methods. In this paper, a comparative method according to the ASTM B 390 standard was used. Further, the linear intersection method according to the ČSN ISO 4499-2 standard was used. The last one for measuring the grain size the image analysis software NIS – Elements AR v. 4.40 was used. Also, the size of the WC crystallites by XRD was measured. Crystallites are coherent diffraction domains in X-ray diffraction. The results show that due to cryo-genic processing, the carbide grain increases but the size of the WC crystallites was decreasing.

The paper deals with the process of solidification of a cast aluminium piston into a metal mould (mould). The introductory part presents the methodology of solution where the physical properties of both the aluminium alloy and the steel mould are presented. Furthermore, the solution itself is described, which is performed on one quarter the size of a piston model by using FEM in the ANSYS FLUENT program. Piston solidification temperatures were recorded every five minutes due to the solution complexity. Next part of the paper pre-sents the evaluation where temperature sections in two mutually perpendicular planes and a quarter a size 3D model of piston solidification are presented. At the end of the paper, an overall evaluation of the thermal so-lidification of the cast piston depending on the solidification time is performed. The results of the numerical solution show that the solidification process begins at 2.5 minutes after casting and ends at 5 minutes. Subse-quently, only the piston and the metal mould itself are cooled.

Nowadays, Carbon Fibre Reinforced Polymer (CFRP) materials are extensively used as substitutes for metal parts in aircraft and automotive components since they are lighter in weight. However, mi-cro drilling CFRP materials during the assembly process poses various challenges such as low hole accuracy and delamination. Hence, an experiment has been executed to investigate the influence of micro drilling parameters towards hole accuracy. The spindle speed and feed rate are the machining parameters that have been considered in this experiment. Three different optimum parameters have been obtained from previous experiments, involving the spindle speed combinations of 8,000, 10,762 and 11,017 min-1 with a feed rate of 0.01 mm/rev. A drill bit with a diameter of 0.9 mm is used to drill approximately 300 holes. It has been revealed that the combination of the spindle speed of 11,017 min-1 and feed rate of 0.01 mm/rev produce high hole accuracy at the 2nd hole compared to the 300th hole due to the presence of uncut fibres at the 300th hole which have reduced the hole area. Hence, out-come of this research could provide the benefit to the industries in term of manufacturing time and materials expenditure.

The paper is focused on an analysis and optimization of the rotary draw benging process to eliminate bent tube ovality by modification of the pressure bar geometry. The bending process is realized on WafiosCNC bending machine. A tube that is bent for an automotive application is made of 34MnB5 steel. Currently, after tube bending process by an angle of 120°, an unacceptable ovality occurs. Therefore, it is necessary to improve the quality of production and thus prevent the formation of unacceptable ovality. In this case, the optimization of the pressure bar geometry is performed. For this reason, a numerical simulation using finite element method in ANSYS software is performed. Before the actual optimization, an accuracy of the simulation is verified by analysing of the current state and comparing it with simulation results.

This work discussed the corrosion behavior of the internal surface of pipeline steel caused by the composition of petroleum products, particularly crude oil. Internal and external pipeline corrosion is the notable cause of pipeline failure in Malaysia’s oil and gas industry. However, internal corrosion is preferred to be concerned in this work because it involved one of the major corrosive media in the crude oil, such as sulfur content. This project aim is to find the sulfur concentration in the crude oil using Fourier transform infrared spectroscopy and atomic absorption spectroscopy. The corrosion rate, corrosion current and corrosion potential of the API 5L X65 grade carbon steel pipeline in different simulated H2SO4 solution concentrations were carried out using the Tafel extrapolation technique. The corrosion properties of the samples were morphologically measured by means of optical microscope, scanning electron microscope and energy dispersive X-ray analyses. The results showed that the corrosion rate of the pipeline steel significantly increased with the increasing H2SO4 concentrations. The corrosion products formed on the pipeline steel surfaces were mainly composed of iron sulfate, iron sulfide and iron oxide. These findings are crucial to understanding the corrosion behavior caused by the crude oil and should be further investigate with the other possible influence factors such as temperature and petroleum’s flowing velocity.

The purpose of this contribution is to investigate different mechanical properties of various types of rubber composite materials that were filled with carbon black nanofiller. The rubber composites were produced from three different basic rubbers. Moreover, the composites were produced with different volume concentrations of the basic rubbers including their various ratios. Mechanical properties of the tested rubber composites were investigated by means of tensile testing, Shore hardness, rebound resilience, mechanical friction, abrasion, visco-elastic behaviour and vibration damping measurements. It was found in this study that the rubber composition has a significant influence on the stiffness of the investigated rubber composites, and thus, on their mechanical properties.

The vertical stability coil is a set of active feedback control coil that is used to deal with the vertical instability of plasma. To improve the response performance, the coil is mounted in the vacuum vessel, which denotes the coil-body will suffer from large electromagnetic force from the plasma current and poloidal field coils. Besides the current flowing in the feeder is nearly perpendicular with magnetic field originated from toroidal coil. It implies large electromagnetic force will be generated on the feeder. In order to withstand the impact from the electromagnetic force, a series of reinforce compo-nents are designed and installed on the coil. It is necessary to verify whether or not the coil conductor and auxiliary components could successfully bear the shock of large electromagnetic force. A three-dimensional magnetic field model is built to accurately calculate the magnetic field and electromag-netic force. Corresponding to the magnetic field calculation model, a more detailed me-chanical anal-ysis model is created to launch the electromagnetic-structural coupling analysis. Based on the stress analysis results, the local structure of the coil is optimized to decrease the peak stress. The updated model is reanalyzed and stress linearization is exerted to extract the different kinds of stress on the coil components. Finally, the stress is evaluated based on ASME analytical design. The evaluation result is helpful to guide the further design optimization.

The design features of diaphragm compressors are discussed in this article. The influence of operat-ing factors on the durability and reliability of a diaphragm made of corrosion-resistant maraging steel is investigated. It is shown that to increase the operational reliability of the compressor's diaphragm elements; it is recommended to use a material, the structure of which contains a certain amount of work-hardened retained austenite. This makes it possible to undergo additional martensitic transfor-mation under the action of peak loads in local areas and increases the structural strength of corrosion-resistant steel for the manufacture of a compressor diaphragm.

Taylor anvil test is one of the dynamic test method in which we can determine the dependences of strain, strain rate, temperature on flow stress. With this method, we can determine in each cross sec-tion or along axial section of the test specimen conditions under different states of stress, strain, strain rates and subsequent changes in the microstructure of the material. This paper describes the experimental results of the Taylor anvil test (TAT) for TRISTAL carbon steel. The experiment was performed on a TAT test facility in the Laboratory of High Strain Rates at the Faculty of Mechanical Engineering in Brno. For simulation of the mechanical behavior of TRISTAL steel under dynamic load condition was used LS DYNA 3D. This paper also contains the results of the Johnson-Cook constitutive equation for TRISTAL steel. The simulation results are compared with the experimental TAT results.

The paper presents results of research under the effect of surface thermo-chemical treatment on the cor-rosion resistance of X6CrNiTi18-10 steel. The corrosion resistance of the surface layers of stainless steel obtained as a result of thermo-chemical treatment (boronizing process) was assessed using the method of progressive thinning, which consists in performing corrosion tests on deeper and deeper areas of the surface layer. This method allowed for the determination of changes in individual characteristic corro-sion parameters read from the potentiokinetic polarization curves and the determination of the depth profiles of these parameters. In the paper, results of tests of X6CrNiTi18-10 steel resistance to general corrosion, performed in acidified sulphate solutions (pH = 1) have been presented. The thickness of the surface layer was assessed on the basis of structural tests and changes in microhardness on the cross-section of the material. It has been found that the extremely high hardness of the boron layer was accompanied by deterioration of the corrosion resistance. The general corrosion rate of the surface layer is 3-4 times higher than the corrosion rate of the material core (substrate). The characteristics of the pas-sive state of steel are particularly worsened, which is manifested by an increase in the value of the critical passivation current, the minimum current in the passive range and by limiting the tendency to secondary passivation.

Contribution is focused on the analysis of power ratios on a drive shaft of a single-stage front gearbox and comparison of design solution of drive shaft using selected materials suitable for shaft production in terms of minimizing gearbox dimensions with respect to maintaining the transmitted power. The aim of the authors is to achieve the smallest possible dimensions of the gearbox shaft by changing the materials from which it is made.

This paper deals with problem of brake elements unstable operation caused by temperature increase in the friction pair contact during braking. Analysis of constructive solutions for heat dissipation from the brake elements is carried out. It is known that the most used design of ventilated brake disks has disadvantage of creating resistance to movement, which reduces the power of the train. Methods and technical solutions for improving the braking system efficiency by stabilizing the friction contact temperature are investigated. Technical solution dealing with heat removing from the friction surfaces was proposed. Materials with phase transition is used in the design of the braking elements. The expert evaluation system software module in Microsoft Excel was developed to calculate the significance of methods for stabilizing temperature in the friction contact. The expert evaluation results of innovative methods for modern rolling stock brake systems efficiency increase are presented.

The process of developing new universal cutting fluids is labor-intensive due to the requirement of conducting experiments to determine the impact of numerous additives on tool life during different technological operations. Therefore, finding the best cutting fluid, the use of which will result in the longest tool life, is a long and laborious process. To reduce labor intensity while creating new cutting fluids accelerated methods are applied first, such as the method of determining the tribometric properties of a new fluid. Subsequently wear tests are carried out, using only those cutting fluids which show the best tribological behavior.
The aim of this study is to reduce labor intensity in developing new universal cutting fluids. For this purpose, a new accelerated method has been developed, which helps to determine the capability of the fluid to counteract the adhesion between the chips and the cutting tool. Furthermore, a new sequence of cutting fluid tests has been proposed which significantly reduces the amount of wear tests, resulting inconsiderable reduction of the overall labor intensity in the development of new cutting fluids.

Face milling is one of the most common machining processes used for the production of high quality flat surfaces. Another important feature of the process is the high material removal rate that can be achieved, or in the case of milling performed at one pass, the high surface rate. Surface rate is increased by increasing feed and cutting speed; both are bound by technological limitations and are limited to rather small variations, especially cutting speed. In finishing face milling, if feed per tooth is increased, subsequently the shape of the chip cross section is altered. This results in the change of the loads of the cutting edges, which influences the cutting forces and process efficiency. In this study, an experimental investigation is carried out in order to determine the influence of feed on chip size ratio. For this purpose, five different values of feed, at two different cutting speeds are tested for face milling. It is concluded that an increase in feed from 0.1 to 1.6 mm results in eight-fold increase of cutting force Fc while surface rate proportionally increases 16 times and specific cutting force only 0.5 times.

The rolling process is widely used to manufacture high-performance splined shaft components. However, there is a convex at root on free end of spline formed by rolling with round dies. However, the analysis and representation of this forming problem are difficulty due to the complexity of motion and multiplicity of processing parameters. This paper concentrates on the corner filling problem, and a physical analog experiment was designed to investigate the problem. The physical experimental results indicated that the designed experiment can reflect the formation of convex during spline rolling process. The finite element analysis of the physical analog experiment process was carried out to study the influences of friction condition and end shape of billet on convex at root of rolled spline. The results indicated that the height of convex will be reduced with increasing friction condition; the height of convex can be reduced by optimizing the end shape of billet. The results of present study provide a basis for optimizing and controlling the forming quality on free end during spline rolling process.

Experimental studies of the wheel rim workpieces with additional technological corrugations have been carried out the results of which showed the ineffectiveness of this technique in profiling to increase thickness of the radial profile junctions of the semi-finished product. The comparison of profiling methods was carried out according to the Cochran's criterion and Student t-test. The additional experiments aimed at the determination of the flexural strain on differently shaped workpieces confirmed the impossibility of creation of the upthrust in the meridional direction during the deformation of the closed shells with straightening of the technological seats (corrugations). It is determined that the seats on the shell unbend in the tangential direction, the bending moments are damped nearthe site of the load application.

The quality of the surface layer of the parts directly affects the life cycle of these parts within machine components. The required surface quality of parts can be secured when keeping a certain operational sequence. Each operation in this sequence affects the final result due to the so-called technological heredity. This means that after each operation it is necessary to achieve certain properties, such as maximum achievable microhardness of the machined surface and residual compressive stresses. This research aims to study the management of machined surface quality after face milling of structural and stainless steels. The laboratory of the Department of Machining and Assembly of the Technical University of Liberec has carried out tests to examine the effect of cutting modes and tool wear on the microhardness of the machined surface after milling.

The gate geometry has a direct influence on casting properties. It was proven that changes in gate dimension (height) influence the permanent deformation values and die cast porosity. The present paper discusses the issue whether changes in gate dimension may affect the structural composition of eutectic silumin. It presents results of the microsection analysis of samples taken from castings made with different gate dimensions to compare the phase α and phase β proportion forming eutecticum. Consequently, conclusions are drawn to examine the influence of gate dimensions on the cast eutectic structure as well as the structure correlation and the selected mechanical properties.