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Surface integrity plays an important role in the functional performance of mechanical components and is one of the most particular consumer requirements in machined parts. Customarily, surface roughness is considered to be the principal parameter in evaluating surface integrity and surface quality on machined parts and has a significant effect on service reliability and component durability. It is dependent on a large number of machining parameters, such as tool geometry (i.e. nose radius, edge geometry, rake angle, etc.) and cutting conditions (feed, cutting speed, depth of cut). The effects of these parameters have not however been adequately quantified. So in order to identify the optimum combination of cutting conditions corresponding to better roughness, accurate predictive models for surface roughness must, as a first step, be constructed. An investigation in this regard has been conducted to address the surface integrity optimisation and prediction issue by applying the polynomial regression method for a variety of experiments and cutting conditions. A higher correlation coefficient (R?) was obtained with a cubic regression model, which had a value of 0.9480 for Ra. The use of the response surface optimisation and composite desirability show that the optimal set of machining parameters values are (250m/min, 0.2398 mm/rev and 2.3383 mm) for cutting speed, feed and depth of cut, respectively. The optimised surface roughness parameter and productivity are Ra =2.7567 ?m and Q = 95.341*103 mm3/ min, respectively. Results show that the models developed can accurately predict the roughness on the basis of measured cutting conditions as input parameters, and can also be used to control the surface roughness by making a comparison between measured and estimated values. Furthermore, operators can benefit from the proposed models if the aim is the reverse determination of the cutting conditions corresponding to the requested roughness profile.

The article concerns the testing two thin-walled fiberglass materials. The aim of this work was to perform tensile tests at room temperature in order to determine the stress-relative deformation dependence in selected directions and to compare the properties of each individual material in these directions. Characteristics determined in this way are to be used as inputs in simulation models forming a part of the process of validating the dummy model’s behaviour in simulations of collisions of the tram front with a pedestrian. Tests have been conducted of such properties of those materials used for external panelling of 15T and T3 tram fronts. The knowledge of these properties is crucial in terms of the mentioned validation. The output of the measurement includes tensile diagrams, including the evaluation of the ultimate tensile strength, elastic modulus and relative elongation at the ultimate tensile strength. Also, the conversion of the elastic modulus for the fibreglass with a different fibre volume part is presented.

This paper highlights the findings of multi-material application in 3D printed specimens. The work presents experimental results of multi-material, and multi-color-based 3D printed specimens by a multi-extrusion printer developed at the laboratory. It aimed to determine the bonding properties between the layers of various materials indicated with different colors. The samples were printed across multiple infill models and tested in the tensile and compression machine. The specimens were created with 10%, 25%, and 100% infill having single and dual colors material. Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), and Flex materials were used for printing various specimens with various colors. The layers were printed synchronously. The filaments were changed according to the predetermined algorithm. The experimental results showed that the mechanical properties of single, dual, and triple mate-rial specimens differed according to the reinforcement strategy. In addition, the mechanical property of the same material with different colors was identical.

The article deals with the failures caused by heat treatment and their identification. The various types of tool failure are occurring from the design through to the tool application stages. Heat treatment naturally plays a major role due to its significant influence on the tool properties, and indeed most defects appear after the heat treatment stages. There are many methods how to study failures of tools and gadgets. One of the most important is metallographic investigation. Metallography is very important part of failure analysis. Thanks to microstructure analysis can be evaluated crack morphology and relationship between the failure and microstructure. Investigation can be performed using classic optical microscopy or SEM (Scanning Electron Microscopy). The aim of this paper is classifying these failures according to type and occurrence to deliver practical solution.

Composite materials play an important role in the machine design. Laminated composites have a lot of advantages but in some cases they show different limitations that are caused by stress concentrations between layers. Discontinuous change of material properties is the reason for occurrence of interlaminar stresses that often cause delamination failure. Delaminations in layered plates and beams have been analysed by using both cohesive damage models and fracture mechanics. Modelling of composite structures by finite element (FE) codes to effectively model delamination is limited. Previous efforts to model delamination and debonding failure modes using FE codes have typically relied on ad hoc failure criteria and quasi-static fracture data. Improvements to these modelling procedures can be made by using an approach based on fracture mechanics. This approach allows us to predict the growth of a pre-existing crack or defect. A study of modelling delamination using the FE code ANSYS was conducted.

The article describes the possibilities of vehicle passability testing by the help of computational simulation. It is used here computing simulation system ADAMS AVT. The simulations can help to find quick answers to basic and additional questions of design change influences in the area of testing vehicle passability. The first part of the article contents description of partial computation simulation models construction which the calculations are associated with. There are mentioned the binding conditions of calculations also. There are mentioned and evaluated the results of performed simulation calculations in the second part of the article. These calculations are performed in order to find out an influence of operation conditions on the vehicle passability. Real operation condition is invasive vehicle speed into a slope in this case. Under investigation are the changes of beaten distance uphill that is the vehicle able to overcome.

The effort to increase the rail vehicle ride speed on existing tracks, or more precisely on modernized tracks with a lot of curves with a relatively smaller radius, lead to use of tilting mechanism of the vehicle body. The paper deals with simulation analysis of a rail vehicle with an active tilting system of the vehicle body, design of the rail vehicle in CAD program CATIA and dynamical analysis in program SIMPACK, with the RAIL expansion. Such body mounting on vehicle bogies is significantly more complicated than the design of conventional rail vehicles. The purpose of this type of body mounting is to increase the size of body tilt during ride in a curve and thus reduce the lateral unbalanced acceleration affecting the passengers, or allow higher driving speed in a curve with the same radius while keeping the lateral acceleration value respectively. Eight variants of different velocity, vehicle occupancy and setting of the tilting mechanism were analyzed. We determined the average value of passenger comfort NMV from the simulation results. We have determined the value of passenger comfort during the ride in a curve PCT from the simulation results.

The object of this article is to analyse the stability of changed three axle rail bogie structure, which is characterized below by higher axle loads combined with good operational properties. The occasion of change was the unstable behaviour of the system during prototype development. For validation of the structure design, there has been created a substitute simulation model in program Simpack, by which the computations were performed for partial system. Model represents only elasto-kinematic properties of the system. For stability analysis of the system, there have been a set of boundary conditions from different degrees of freedom to state out of balance. Simulation calculations show, that up to one oscillation in the y-direction, which is damped in real bogie by friction in suspension and dampers Lenoir, is the system after all deflections in initial condition. Substantial unstable behaviour does not show already.

The design of the gating system is a major factor in the internal homogeneity for casting. A properly designed system should ensure a proper and continuous filling of cavities in a mold. A continuous filling in a mold cavity gives the initial condition for internal soundness and homogeneity when casting, which in turn is reflected in the quality and mechanical properties. The geometry and shape of the gate models and directs the melt stream entering the mold cavity, this greatly affect the properties of the castings. Homogeneity of castings closely correlates with the mechanical properties of castings. The present paper is devoted to analyzing the effect of the dimensions of the inlet slit on the homogeneity of the casting. As the width of the gully is constant according to the design method of the ingate systems, the variable parameter was the height of the gate. The aim of the experiments was to find the most advantageous height of the gate that is necessary to achieve the lowest porosity values. The boundary values of the height of the gate were determined based on the numerical design of the ingate system for the particular casting and the NovaFlow & Solid simulation program. The porosity analysis f was performed by the OLYMPUS GX51 microscope and the evaluation of the samples was carried out using the ImageJ computer program.

Passing of vehicles along curved track is a serious technical problem, which needs special attention. It is especially actual in the environment of urban lines, where it is necessary to pass a track of small radius. There is a significant strain of track as well as tram's bogies. It results in excessive wear in rail-wheel contact. Considerable is also the noise caused by operation on such track. Behavior of the vehicle when riding along track curve is influenced by the wheelset guidance design. If the wheelset guidance is able to set the wheelsets in track curve to a radial position, mitigation of the negative phenomenon can be expected. This paper deals with a design of a mechanism for setting wheelsets in a track curve to a radial position for tram cars. Dynamical analysis of a simplified tram car model was performed. Courses of monitored values of bogie with and without designed mechanism are compared.

Main aim of this article is description of weld line influence on mechanical properties of plastic parts. Special design of mold was created for this research. This mold is able to create specimens with and without weld lines. These specimens undergone tensile test according standard ASTM D638 with different results. Strength and strain results were compared for both types of specimens. Nylon PA6 without any internal reinforcement was used as reference material during testing. Both specimens were investigated also by microscope in order to see composition of weld line and plastic material. Microstructure showed geometry of weld line and also fracture surfaces indicated presence of plastic deformation

This article is belonging to the publication series, which we published in the previous issues of this journal and there are described the most important and innovative research and development design solutions and computational procedures as part of European structural funds project. The main object of article is the strength test of new design of freight bogie frame through FEM analysis. For the calculation of the analyzed parts of the bogie through finite element the program ANSYS was used. Results of calculations prove, that new designed construction of the bogie frame satisfies strength conditions.

This paper deals with affecting of corrosion resistance of X12CrMoWVNbN10-1-1 martensitic stainless steel after plasma nitriding. This steel was subjected to plasma nitriding at lower temperature of 400 °C for 15 h in the reverse nitriding atmosphere 1H2:3N2 (l/h), tested and then compared to untreated one. The microstructure and microhardness of the untreated and nitrided stainless steel were evaluated. The anodic potentiodynamic polarization tests in neutral 2.5% NaCl deaerated solution were executed and the corrosion properties of the untreated and plasma nitrided steel samples were evaluated. The results showed a nitride layer, consisting of nitrogen rich diffusion layer but without compound layer on the surface of the plasma nitrided X12CrMoWVNbN10-1-1 stainless steel. The surface hardness of the martensitic stainless steel after plasma nitriding was increased significantly. The corrosion resistance of the X12CrMoWVNbN10-1-1 stainless steel was increased only partially. The pitting was evaluated, and the pitting coefficient was calculated. The plasma nitrided steel showed higher (more positive) corrosion potentials, lower current densities and decreased corrosion rates and pitting during electrochemical corrosion tests compared to not nitrided steel.

The paper deals with design proposal of a cover part of a strength bumper, which is tasked with creating the outer design lines of an automobile without sharp edges according to legislation in force and also with protecting a vehicle against damage. The cover part serves for covering the strength part of a back strength bumper, which will be equipped with a winch and used in off-road vehicle Nissan Patrol Y61. Another aim is to perform a FEM analysis of the strength part of the bumper loaded by towing force of the winch and thus to verify a safety of the structure. The next solution of the issue will be an approach to real testing, which will verify a correctness of a numerical computations and also fulfilment of the purpose of creating the structure. Bases of FEM analysis and practical experimental verifications of the structure will be also used as a background for granting approvals, certifications and type approval by superior authorities.

In a competitive market the manufacturing companies have to produce cost effective products which can be realized by minimized production cost and higher effectiveness. The application of Lean manufacturing philosophy in order to optimize costs and quality is gaining a competitive advantage. There are lots of Lean tools which can result the improvement of the production line performance.
The article is original and unique, because beside the description of theoretical background relating to the process improvement, a practical method is also introduced in a case study.
In the study the author describes the main general steps of a Lean project completed in an industrial environment. The described case study which is a part of a real R+D project shows how can be improved the efficiency and reduced manufacturing cost of a real manufacturing system by application of several Lean tools which are One-piece flow, Takt-time analysis, Line balance and Cellular design.

Reverse engineering is a technology that enables acceleration of data collecting for CAD, CAM, CAE systems, which also means shortening time of development, construction and components production. It is a transfer process of a physical component to a digital format. Generally, the technology of reverse engineering means a conversion of analogue data to digital data that are further processed. Every single industry branch rising their requirements on accuracy, dimension, quality, etc. Therefore, digitisation is applied in many production fields such as an automotive industry, aircraft or shipping, medicine, industrial design, design, etc.
An article deals with an analysis of prototype models of gears in various stages of production. The realized inspection of a shape of prototype gears lied in uploading of a digitised referential CAD model (the gear after heat treatment and machining), subsequent setting up of digitised prototype gears (the gear after the machining, gear after heat treatment) in respect of this referential CAD model, a control of their dimensions and forming a colour map of deviations in chosen points.

The aim of the article was to check the internal defects in the butt welded joints by non-destructive TOFD (Time of Flight Diffraction) technique. Subsequently, the macrostructure from the defect indication site was evaluated and assigned to the TOFD ultrasound indication. Basic knowledge of ultrasonic TOFD testing are described in the theoretical part of a submitted paper. Ultrasound technique TOFD is non-destructive method that can detect internal defects inside test material without damaging it. It is a reliable method for detecting mainly flat internal defects such as incomplete root penetration, lack of fusion, etc. Ultrasonic test procedures and test results obtained in non-destructive testing of butt weld are shown in experimental part. Evaluation of the ultrasonic TOFD testing results, its advantages and disadvantages are described at the end of this article.

On the base of a well-known method of machining with disk-shaped rotating tool the self-propelled tool was designed. The principle is based on braking the tool rotation during machining, until the moment of determined wear criterion on the tool flank. As with the growth of tool wear the force of cutting resistance increases, it is possible to use it for automatic tool swinging into a new position by which a new part of cutting edge comes into engagement. The paper describes the tool design, theoretical analysis of Rz after machining and actual experimental machining results.

Aiming at the problem of platform planning and module identification in product family design, modular theory, implementation methods and objectives are studied in mass customization(MC), and a dynamic planning model is established for product platform and module. Firstly, the versatility and physical consolidation of existing variants are analyzed and expressed using directed and undirected graphs. And then a dynamic planning algorithm, in which the platform threshold and the module boundary parameters are set dynamically based on market demands, is proposed in product platform and module design. Secondly, potential parts are extracted for more variant products in product family design. Finally, the effectiveness of the proposed approach was demonstrated by the dynamic planning for parts of different humidifiers.

Burnishing is a cold working process with superficial plastic deformation, which is to exert an external pressure through a very hard and smooth roller or ball on a surface to occur a uniform and work-hardened surface, to make it possible to reduce roughness, to increase the hardness and to produce residual stresses of compression. The unalloyed S 355 J0 steel specimens were machined on a conventional lathe to the proper dimensions; these machined specimens were then burnished by a simple locally designed and fabricated roller-burnishing tool. The main objective in this work is to determine a mathematical models statistically based on experimental design (response surface methodology) using central composite second-order rotatable design which allows to give the relationship between the two out parameters surface roughness and hardness, representative of the superficial layer surface caused by the four internal roller-burnishing parameters called: burnishing speed, force, feed and number of passes of the tool. The experimental results indicate that feed, burnishing force and speed are the most important and significant parameters to improve roughness surface, and feed, speed, burnishing force and number of passes are the most important and significant parameters to improve superficial hardness of S 355 J0 steel specimens. The surface roughness and hardness were improved from about 2.5μm to 0.15μm and from 176 HV to 226 HV respectively. The validated models with coefficient of determination R2 = 93.1% for surface roughness and R2 = 89.8% for hardness, seem correlate well with the experimental results.

The macroscopic structure of a casting has a direct impact on its mechanical properties. The porosity and homogeneity of a casting closely correlate with its tear strength characteristics. In order to achieve the best mechanical properties, it is necessary to eliminate internal defects in a casting. The elimination of such defects can be achieved through the suitable adjustment of the input parameters of high pressure die casting machines prior to starting the actual casting cycle. This method is useful for companies that produce castings on the basis of supplied pressure forms, whereby it is impossible to influence the design of the gating systems. A much more appropriate way to influence the homogeneity of a casting is to design the gating system so that possible shortcomings are already underpinned and excluded in the design and development phases. By adjusting various elements of the gating systems it is possible to achieve significant improvements in the properties of a casting. The construction of the gate has the biggest influence on the final homogeneity of a casting. The gate is the point at which the modulation of the melt flow rate takes place for the filling of the die cavity. The mode in which the cavity is filled and the speed of the melt flow rate are the main determinants of the final characteristics and properties of a casting. This paper presents an analysis of the macroscopic structures of castings produced under various gate construction modifications and their effect on the mechanical properties of those castings. Conclusions, which are drawn on the basis of the detailed analysis, describe the correlation between the macroscopic structures and the mechanical properties of castings with precautionary measures that are used and implemented directly in production.

This paper deals with the use of lean manufacturing methods to streamline the welding line in the au-tomotive industry. The automotive industry is constantly developing and innovating its production envi-ronments and technology because of growing competition on the market and customer demands. Cur-rent trends of car makers include pressure to reduce costs and increase production efficiency. With the commencement of new technologies, the production lines began to innovate and the production cycle began to constantly accelerate. The paper deals with the reconstruction of the welding line, which produces parts for the rear axle of a compact SUV. The case study aims to identify bottlenecks and set innovation plans and their evaluation in possible implementation. In the paper, lean manufacturing methods are applied in order to deter-mine the ideal solution for ensuring the quality and ensuring the efficiency of the production line, lead-ing to cost reduction. Through these innovations and modernizations, the company will be heading for digitalisation that changes the core of the industry.

This paper presents a study focused on sandwich structures as well-known train construction materials that are composed of two thin and rigid face sheets and a thick, low-density core material. For trains, the wheel-rail inter-face is the main source of noise, and the wheel-rail roughness, especially in the presence of rail corrugation, is the main excitation source transmitted to the interior and area for passengers. The purpose of the study is to optimize the acoustic properties of a composite sandwich panel used for train floors and walls. Sound absorption coefficient (?), noise reduction coefficient (NRC) and Transmission loss (TL) evaluations have been implemented and experimentally validated on a typical sandwich material used for trains. The opportunity to use a different material can be concretely calculated and modified for critical frequency ranges. Sound transmission loss levels of the structural components as the floor and wall of the train body, which are required of producers and cus-tomers, were tested in acoustic laboratory and acoustic devices according to ASTM and ISO standards. It is demonstrated that, for honeycomb and cork sandwich panels, acoustic response is not sensitive to cell size. For foam core sandwich panels, it is observed that different compositions with thin layers are effective in the fre-quency range of 50 - 1000 Hz.

The article deals with the application of computed tomography in dimensional quality control. The advantage of computed tomography is that the measured part is not influenced by measuring force. It is possible to measure complex parts and assemblies, their geometry, internal structure and defects in one step. The disadvantage of CT is decreasing accuracy and resolution when measuring hi density materials or larger parts, which leads to usage of high accelerating voltage and current. The measurement result is influenced by many factors, not only the instrument itself and the set of measuring parameters, but also largely depends on the sample itself, on its material and geometry. Based on the requirements for dimensional inspection, an analysis of the dependences of individual parameters of the Zeiss METROTOM 1500 computed tomography was conducted. The dependence of the spot size of the X-Ray source on the accelerating voltage and current was determined for the given instrument, as well as the relation between the voxel size and the distance of the sample from the detector. Spot size and voxel size has to be in relation, since large spot size goes against high magnification, high resolution meaning small voxel size. Using calibration artefact, the influence of the acceleration voltage on the accuracy when measuring form and size of a sphere and the distance between centres of 2 spheres was evaluated.

Observation and identification of products of transformation of austenite during austempering, Q-P processing, or quenching and tempering are often challenging. The reason is that the resulting microstructures are typically very fine and provide insufficient contrast between microstructural components. Their analysis requires scanning or transmission electron microscopy which demand rather complex sample preparation procedures and involve high costs of maintenance of microscopes and accessories. However, in-process inspection of products of heat treatment calls for simpler and rapid methods of microstructure analysis using a light microscope.

The geometric accuracy is significant property of the product. For semi-finished products, this accuracy may also affect the accuracy of the final product (the resulting mechanical component). Geometric accuracy (inaccuracy) can be transmitted from one operation to the next in production - technological heredity arises. It is, therefore, essential to analyze the deviations on the produced areas and take measures to ensure that the negative effect of one operation was not transferred to the next operation. It is insufficient to analyze only the numerical values of the measured deviations. It is necessary to directly analyze the measured profiles in the field of macro geometry. The paper presents a stability analysis of roundness profiles measured on the drawn tube. The analysis uses knowledge from harmonic analysis and from the Fourier series. The measured roundness profiles are divided into individual harmonic components. Arithmetic means of amplitudes of individual harmonic components are moni-tored. There were analyzed parameters determining the stability of the profile - standard deviations.

This paper focuses on the implementation of principles of Industry 4.0 concept to the ceramic industry. The topic of this paper is to address the problematics of the implementation of processes and elements of digitization within the Industry 4.0 concept into the ceramic industry. Firstly, thorough literature and best-practice research will be discussed. Based on the state of current knowledge, the concept of the Industry 4.0 Readiness Model for Refractory will be presented. The model’s main focus is on the readiness of current business structures, processes and technical and economical situation. It will provide the necessary analysis and insight into the potential company’s processes and background. Based on this analysis, it will be possible to define the main obstacles for future digitalization and automation within Industry 4.0 the concept in Refractory industry. On the foundation of data obtained by Industry 4.0 Readiness Model for Refractory, it will be possible to implement the Industry 4.0 solutions with the highest added value to a specific company, based on its current state. The main purpose of this paper is to summarize and discuss key parameters and framework for Industry 4.0 Readiness Model for Refractory and its connection to future implementation of Industry 4.0 features within the ceramic industry.

The aim of the paper is to introduce the digital twin concept as part of the Industry 4.0 strategy. In the form of a case study, the procedure and outputs of the simulation of a specific production plant to-gether with its intermediate storage and output for the next plant are presented. In the research part is presented a simulation model of production lines and intermediate stock with material flow represen-tation. At the beginning of the research the analysis of production and logistics processes was carried out. The next part describes the programming methods used to record and redirect material flows between individual lines and stock. The simulation method using simulated production line models enables the digitization of dynamic production processes in enterprises. We expect that in the coming years there will be an increase in demand for the creation of simulation models of production systems in modern manufacturing companies that will try to implement the Industry 4.0 strategy and thus in-crease their competitiveness.

High-strength X3NiCoMoTi 18-9-5 maraging steel belongs to highly researched materials due to its wide application range. Thanks to its outstanding mechanical properties, it is usually used for high-loaded parts in the aircraft and aerospace industry. Hardness and ultimate tensile strength are strong-ly affected by heat treatment allowing to create Ni3X (X = Mo, Ti), Fe2Mo, and (Fe, Ni, Co)3(Ti, Mo) precipitate which almost doubles their properties. In the present study, microstructure and mechani-cal properties of the thermo-mechanically processed maraging steel were studied two modes of heat treatment. Microhardness values improved from 350 HV0.1 to 650 HV0.1, and ultimate tensile strength has increased from 1029 up to 2140 MPa. On the contrary, elongation has reduced from 11 to 4 %. After heat treatment, precipitates Ni3Mo has been formed in the material volume.

Plasma cutting is an ever-evolving method of industrial cutting of materials. Like all modern methods, it must meet the requirements for the quality of the cut, but also the hygiene and safety regulations set by European legislation. New ways are being sought to reduce process noise while improving the quality of the cutting surface. The article aims to compare two cutting modes (Contour Cut and Silent Cut) in terms of both the quality of the cut (roughness of the cutting surface, size of the heat affected area, perpendicularity and bevel angle of the cutting surface) and in terms of noise of the cutting pro-cess. The results in the article clearly show that the use of the Silent Cut mode has a demonstrably positive effect on the level of noise produced but also on the quality of the cut.