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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.

This paper introduces a non-destructive method of analysis of the internal structure, occurrence and pore size in a specific volume of geopolymer composite material, with and without the addition of inorganic fibres in the form of meshes using computed tomography. A desktop micro-tomography device Skyscan 1272 was used for visualization and accurate analysis of the interlacing points in the basalt and carbon fibre meshes and for evaluating the adhesion of the fibres to the matrix of the composite material. An appropriate resolution was selected both for displaying the interlacing points in the inorganic fibres and for visualization and analysis of the geopolymer structures. The method makes it possible to evaluate the differences in the structure of the studied materials in a non-destructive way and to check the adhesion of the fibres to the base material.

Metal additive manufacturing provides an efficient way of processing metallic cellular structures. This relatively novel way of production is based on a powder bed which is melted using a powerful laser. Despite the advantages of this production technology, differences in geometry are observed between the CAD model and the manufactured structures. With this in mind, a series of thin struts were made and their geometry analysed using optical-scanning microscopy. Various building directions and strut diameters are studied. The effective stiffness of struts are measured and verified by tensile tests. The results point to higher strength of inclined struts than perpendicular specimens.

Traditional PID fails to meet the requirements in control precision and response speed while implementing a nonlinear control. Such problem can be easily solved by adaptive fuzzy PID, which indicates that the adaptive fuzzy PID will realize the precise control in engine speed control system, a typical nonlinear system. This paper first discusses the mathematical control model of diesel engine speed-control system and the characteristics of the traditional PID control. Then, the speed control principle of the adaptive fuzzy PID controller is analyzed. Besides, the membership function of fuzzy logical, the fuzzy logical variable and the fuzzy reasoning rules are determined. Next, the adaptive correction method is briefly introduced. Finally, the model of traditional PID and adaptive fuzzy PID controller are simulated and the same disturb is added into the control systems. The simulation results show that the adaptive fuzzy PID controller has better performance in dynamic response and robustness than that of traditional PID.

Our workplace, Technical University of Liberec, is currently engaged in research and production of cellular metal systems. Basically, cellular metal systems are materials with lower density. It is a research in the field of mechanical engineering that is focused on the development of new materials. In general, many methods have been developed for the production of cellular metal systems, e.g. by BANHART [2] or ASHBY [4]. At their production, the direct gassing of molten metals (mostly aluminium ones) or gassing by the powder agents (e.g. specially formulated aluminium powders) are mostly used. Depending on the manufacturing method, a cellular system with open or closed cells can be obtained. The most commonly used metal is aluminium and its alloys. We are currently focusing on the production of porous aluminium by using sodium chloride. Sodium chloride occupies regular sites in the aluminium material and thus contributes to the aluminium porosity. After solidification of the aluminium, sodium chloride is dissolved in water. Sodium chloride is relatively inert to the aluminium and together with it, has a favourable density (2160 kgm-3) compared to the aluminium density (2700 kgm-3). The values of these physical quantities were observed on the produced aluminium test specimens having  60 x 10 mm: relative density of porous system REL; porosity of metal system P; amount of solid phase system volume fraction VPM; density of porous metal system PM and porous material Young's modulus of elasticity EPM.

This paper deals with basic methodology of surface evaluation of functional surfaces, which were prepared by various machining methods (turning, milling and grinding). Here are the basic 2D (profile) parameters and 3D (spatial) parameters and their properties in relation to the machined surface. Parameters of machined surfaces were obtained by CCI Lite Coherence Correlation Interferometer from Taylor Hobson and evaluated using the TalyMap Platinum software. The article further demonstrates the inappropriateness of the surface structure assessment with only the parameter Ra (mean arithmetic deviation of the profile), which is the most common method in technical practice. This methodology extends the possibilities of a comprehensive assessment of exposed surfaces of machine parts.

Additive manufacturing (AM) of metals is expanding and already starts to reach industrial scale. Among many different technologies of AM, powder-bed technologies are the most widespread as they provide the highest resolution and so the widest options in the production of complex parts. Selective laser melting (SLM) and electron beam melting (EBM) both belong to this technological group. In this paper, we describe the differences between these two technologies on the example of titanium alloy production. Due to different material states in the as-built condition, the material shows a different response to heat treatment. We depict the differences by microstructure observations and hardness measurement after annealing the titanium alloy at temperatures of 100-1000 °C and subsequent water quenching. While the titanium alloy is stable when manufactured by EBM, it shows microstructural changes associated with changes in mechanical properties when manufactured by SLM.

Automatic workpiece exchange is one of the important parts of every flexible manufacturing system. This part largely allows complete automation of the component's production cycle. It also greatly contributes to a significant reduction in the workpiece clamping times and contribute to a reduction in the downtime during the machining process. It also allows eliminating a human factor from the production process, thereby contributing to greater machine utilization and higher machining productivity. This article describes certain modifications of interchangeable pallet system designated for specific training CNC machine tool EMCO Concept Mill 105 situated in the laboratory at the Department of Automation and Production Systems. This machine has considerably limited workspace and length of feeds which are the most limiting parameters during design. Mentioned modifications allow manipulating with designed pallets with the industrial robot or special manipulator instead of previously designed manual handling.

Presented research paper is focused on the development of carbon fibre wheel. Considering development and construction of wheels for the automotive and motorcycle industry, low weight is one of the most significant factors. In the case of rotating components, the imbalance of the assembly is a problem. This fact affects handling of the vehicle or wheel behavior under the load, for example in the point of turning, acceleration or drive on damaged road. Determination of the most appropriate material composition (sequence) is primarily the main problem of composite material application. Correct design of material composition and also lay-up diagram is determined by material characteristics and strength requirements. A suitable solution is in the application of a group of input material structures creating hybrid composite. Specific combination of various input materials (aluminum ring, 3D printed plastic honeycomb core and carbon fibre composites) guarantees and ensures the fulfilment of the strength requirements which are determined during each particular application. The main aim of presented paper was to design material composition and shape of carbon fibre wheel that were subsequently verified by successful manufacturing process.

Direct Metal Laser Sintering (DMLS) is a method of additive manufacturing (AM), which builds metal parts in a layer by layer procedure based on a CAD template. The melting of metal powder by an energy beam and successful mastering of the whole manufacturing procedure requires complex management. Physical and chemical metallurgical phenomena occur during melting of the material and the final microstructure depends on many factors. This study investigates the microstructure of struts depending on their distance from the building platform. It is known that metal powder does not allow the dissipation of heat in the same way as molten material due to gas interstitial volume between the spherical particles. Metallography and micro-hardness were investigated on maraging steel 1.2709. Different melting strategies are recognizable in the macroscopic structure of metal alloys. Interesting facts have been discovered, for instance lose molten group or change of hardness depending on a shape of metal cells. In generally, significant differences were not found between individual specimens.

Drawing process is generally influenced by many technological parameters (e.g. holding pressure, friction coefficient, etc.) and all of them should be considered for numerical simulation of such process. This paper deals with the possibilities how to determine one of the parameters that is quite difficult to be taken into account - magnitude of heat generated during forming process. In this case only heat generated by plastic deformation was determined, thus static tensile test at different loading rates was performed. Contact-less optical system ARAMIS and Thermo-camera FLIR SC660 was used to measure distribution of both plastic deformation and temperature on samples surfaces.

The anisotropy coefficient rα [1] represents one of the main aspects of the materials deformation behavior, in addition to the basic material characteristics (such as e.g. yield strength, tensile ultimate strength, total ductility, uniform ductility). According to the standard, its value is calculated at a specific deformation value using the initial and actual measured length and width. However, modern materials testing methods offer the possibility to determinate its size throughout the deformation process that is however limited by the uniform ductility due to neck formation. In this paper, two such "modern" approaches are compared, where the values of anisotropy coefficient calculated according to the standard (i.e. just in one deformation value) are used as etalon. As these new testing methods, a mechanical strain gauge was used to determine the anisotropy coefficient throughout the whole static tensile test and optical contact-less deformation measurement system as well. Thus as the aim there was not only to measure and compare the anisotropy coefficient values courses during the static tensile test up to the uniform ductility, but also to compare them with the results measured by standard just in one deformation value. Possible utilization of these data can be found in the numerical simulation software.

The aim of the work was to evaluate the whole system of the springs of a passenger car. The influence of inflation and the type of tires on the acceleration of the various parts of the car (axle, steering wheel, driver's seat attachment, body shell and acceleration affecting the driver) was investigated. The types of shock absorbers and springs of the passenger car were also examined. The sensors used acceleration and pressure sensors between the wheel and the road using test stands. The benefits and reserves of the individual systems were compared, and in the systems with the cushioning rigidity, all the suspension setups were evaluated. The work was done experimentally in laboratory environment as well as in real operation.

Adhesive bonding technology present a perspective method of various materials bonding and replacing conventional bonding e.g. welding. A geometric shape modification of bonding material and an adhesive reinforcing by glass fibres to increase tensile strength of adhesive bond was subject of this research. The bonding material was modified into preformed angles 5°, 10°, 15°, 20° and adhesive bond with 0° was se t as the etalon. The adhesive was modified by glass fibre with weight 80, 110 and 160 g.m-2. The research proved tensile strength increase from 4 to 48% by various preformed adherent angles. The research also proved tensile strength increase from 4,8 to 93,7% by adhesive reinforcing with glass fibres with various weight. Statistical analyse proved significant difference between measured values on significance level 0.05 (p < 0.05) i.e. influence of adhesive bond modification on mechanical properties was proved.

The given paper is closely connected with the experimental and numerical modal analysis of the carbon composite plate damaged by cut. In relation to the tested carbon composite, modal analysis was performed by help of special measuring device Pulse 12. The mentioned device was supplied by company Brüel & Kjear and the experimental measurements were carried out using damaged and undamaged plate sample which were prepared from the mentioned material hereinbefore. The investigated and analyzed plates of carbon composite were made of six layers of carbon fibres and they were arranged under the angle 90º (it is like fabric material made off carbon fibres). The layers arranged in the given way were joined by epoxide resin MGS 285. The experimental measurement of eigenfrequencies of carbon composite plates was carried out using the undamaged and damaged sample with proportions 78 mm x 78 mm while ten measurements were performed for each one specified site of the sample. In relation to the damaged plate sample, there was cut in length of 20 mm in the centre border. The finite element method in the software system ADINA v.8.6.2 was used for numerical analysis of the eigenfrequencies.

The main aim of this study is structural changes on the layer of Al-Si cast alloy by laser austenitic stainless steel 17 246 deposition. In order to remelt the Al-Si alloy surface the laser of 1, 9 kW has been used for facing area, and 1.6 kW for the edge. The linear laser scan rate of the beam was set 450 mm.min-1 for facing area, and for the edge 550 mm.min-1. We observed that the thin surface made of austenitic stainless steel had a lot of splits. The purpose of this study is also to enhance inherent properties of the surface materials to create new product or improve on existing one.

Topological optimization is the process of reducing part weight while respecting strength requirements. This paper focuses on its possible positive consequences for the machining process. The main aim is to carry out a survey to obtain knowledge that will be applied during the topological optimization of a milling tool. According to all the indicators, the efficient implementation of lattice structures into the milling concept has the potential to achieve a high level of innovation, since the functional weight reduction of the tool allows for higher dynamics of the cutting process. The modified rigidity of the milling cutter and vibration absorption can extend the life of the cutting edge, and such a milling tool would provide a competitive advantage on the tool market.

To build the car body parts of today's cars, materials of higher strength are used on an ever-wider scale. They are, for example, boron-containing steels, which are highly resistant to special thermo-mechanical processing, coated with AlSi; e.g. USIBOR 22MnB5 type materials. For the final assembly of all body mounting components, it is necessary to apply different types of joining stud elements. One of the possibilities of making joinings between sheets and fastening elements - studs is the technology of short-circuit stud welding.
This article aims to evaluate the influence of welding parameters of steel studs on high-strength steel sheet type USIBOR 22MnB5 with AlSi coating on selected mechanical properties of joints.

The paper deals with the change in mechanical properties and wear of 90MnCrV8 universal tool steel after plasma nitriding, which is widely used to produce cutting tools with good durability and low operating costs. Plasma nitriding was performed at a temperature of 500 °C for 10 hour period in a standard N2 /H2 atmosphere with 1:3 gases ratio. Microstructure, phase structure, thickness of a nitriding layer and surface roughness of samples were measured with optical microscopes and a profilemeter. Verification of a chemical composition was carried out on the BAS TASMAN Q4 device. Wear resistance was measured on a universal TRIBOLAB UTM 3 tribometer, through a "pin on disc" method. The results of experiments have shown that plasma nitriding process, significantly improves the mechanical and tribological properties of selected materials.

Brass mechanical properties are not ideal, particularly when the brass is exposed to the effects of mechanical wear. Final finishing of functional surface of machine component is substantial for the particular choice of brass. The aim of the research was to approve or disapprove the hypothesis if abrasive - free ultrasonic finishing (bufo) of brass has higher wear resistance of surface compared to the classical machining. The results of the experiment showed that abrasive - free ultrasonic finishing (bufo) has a major impact on the size of the elliptical wear area. Surface finishing by classic machining formed on average a 41% larger elliptical wear area compared to surface with abrasive - free ultrasonic finishing. The hypothesis of experiment were verified and it is possible to consider that abrasive - free ultrasonic finishing (bufo) has considerable influence on wear resistance of the surface of machine parts.

This paper presents the theoretical calculations of the foaming process of selected powder foaming agents (TiH2, CaH2, MgH2, ZrH2, CaCO3 and MgCO3) regarding the volume of gas, relative density and density of the metal foam obtained with respect to the use of a certain amount of powdered blowing agent. This work is carried out in the frame of the university project in which a small subproject is dealing with the problem of the cellular lightweight metal structures. Furthermore by calculating the diffusion of hydrogen in both solid and liquid aluminium there were found results for the duration of the anticipated action of the powdered blowing agent (0.75, 1.0, 1.25, 1.50, 1.75 and 2.0 wt. %).

This article intends to present the first results of a long-term research project, which will result in developing a validated model of a pedestrian for the simulation of crash tests involving tram fronts and, where applicable, the fronts of other urban rail vehicles. The current phase of research includes results of the pilot experiment with a crash-test dummy, and these results supplement the results from simulations, thus demonstrating how important it is to pay special attention to the individual stages of a collision event and how important the localisation of and moulding by an individual tram's front panels are for the nature of the monitored stages. In the first stage, inertia of individual body segments plays a significant role, with the primary contact taking place between the tram's bumper and dummy's thigh. The dummy subsequently " takes the shape" of the tram's front with progressive bumps to shoulders and head following. At that moment, the tram brakes, and the dummy begins to disentangle from the front panel. The friction force between the dummy's soles and the surface of the rail track is very significant for the nature of this second stage of the collision event .The dummy then hits the ground. It is an accelerated fall, and under the given conditions, it is the stage that has the most devastating impact on the dummy. The simulation made shows the way to modify this dangerous stage to be less harmful to a pedestrian involved in a tram collision.

Previous work has proposed a process for implementing a lattice structure into a milling cutter body based on clustering in the milling cutter with modified main dimensions of a BCC cubic lattice structure cell. A finite element analysis model has been created to predict the strain and deformation in the struts of the lattice. The prediction made according to static loads demonstrates that the concept of a lightweight cutter meets the strength requirements, though its stiffness does not reach the fully-filled version. The methodologies for creating the FE model are described in this paper. HyperWorks with OptiStruct were used for these analyses. Local stiffness could be improved by varying the strut diameter or using a different type of basic cell for the lattice structure in problematic locations, especially in the area of the connection between the shell of the cutter and the lattice structures.

The aim of this work was to verify the applicability of the TVS (Transfer Vibration through Spine) methodology for registration of changes in viscoelastic characteristics of the axial system. The detection method consists in applying γ pulse pulses with a half-width of 5ms and then a harmonic excitation of continuously varying from 5Hz to 160Hz on vertebrae C7 and L5. This ripple is transmitted along the axial system and acceleration of all the spinous processes of the vertebrae is sensed by accelerometer sensors to propagate the wave between C7 and S1. On the basis of measured data (input excitation and its sensed response on spinous processes), the change of total viscoelastic parameters of the spine was evaluated before and after monotonous or other spinal strain or before and after relaxation. Existing results confirmed the TVS method is suitable for detection of mechanical changes of the axial system. It was proven transmission of ripples through the axial system of a person also changes by the influence of alternations created by monotonous or physical strain or conversely relaxation.

This paper deals with investigation of vibration damping properties of grey iron by means of modal analysis in SolidWorks software environment. Modal analysis is accompanied by material study of metal matrix and graphite particles evaluation. Grey iron is one of the most used cast materials, in relation to good damping properties and high pressure strength. To obtain the required mechanical properties it is necessary that the graphitic particles be evenly distributed in the metal matrix and had the optimum size and shape. Flake shape of graphite decrease tensile strength of grey iron, but a suitable method of inoculation, it can cause an increase of tensile strength up to 350 MPa. Flake shape of graphite particles increases the thermal conductivity. Grey iron is material with used in the manufacture of heavy machine stands, pump bodies and low-stressed sliding bearings in the context of with its characteristic material properties.

This article deals with state-of-art in the field of handling machines intended for disabled people, which serve for disabled entry of such people and for people with delimited locomotion. It contains calculation of forces, which act in the mechanical system of an electric device during its operation in real conditions, changes of reactions depending on the load and the climbing angle as this solved handling machine will designed for negotiation of staircases. The objective is the functional calculation of a driving mechanism of a stair chair marked SA Alfa, i. e. the calculation of loading forces and their action on the driving mechanism. It will serve in the next step as an input for the calculation of a required power under conditions of occurance of maximal resistance forces, which will be determining factor for dimensioning of driving components of this device.

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.

The paper deals with problem of construction for Weightlifting in CrossFit from point of view of material parameters. The specific structure has to withstand repeated impact loads. Therefore it is also necessary to deal with stress-strain states. Because of behavior of impact loading and elastomers used in FEM computational model, explicit integration scheme and material constitutive models have to be included. To use constitutive models, material parameters have to be well known. In this paper, the 2-parameter Mooney-Rivlin model is used. That is the reason, why this article is focused on obtaining material parameters of elastomers for FEM computational modeling based on their hardness. Mooney-Rivlin parameters can be determined on the basis of the Shore A hardness. There are exist equations which can be used conversion of the mentioned hardness to material parameters of elastomers. The procedure is such that the Shore A hardness is converted to the elastic or shear modulus and then Mooney-Rivlin material parameters are determined from the modulus. But these equations can lead to different results for the same hardness. In this paper, these results are comparison. For create a 3D model the SolidWorks software is used and for FEM analyses well-known the ANSYS Workbench software is used.

Paper deals with the evaluation of protective coating surface layer Al-Si at boron steel 22MnB5. Parts from these steels are used at the car-body design. Such parts are produced by hot forming technology that means not only higher requirements on material but also on the surface layer. Coatings are used to protect surface against oxidation during heating and also support the own forming process inside the tools. In this paper is evaluated the protective layer change during heat treatment - heating in furnace (8, 12 and 16 min). Performed microscopic analysis of Al-Si surface layer proves the thermal regime influence on the change of coating properties.

Aiming to study the working efficiency and stability of the loader, the hydraulic system of the loader is studied. Taking the ZL50 loader as the research carrier, the working conditions of the loader and the working principle of the hydraulic system are analysed at first. AEMSim software is used to simulate and analyse the hy-draulic system, and the necessity of using the algorithm to optimize the hydraulic system is put forward. Secondly, the mathematical model of key hydraulic system optimization is deduced, and genetic algorithm and neural net-work algorithm are used to optimize the analysis of the objective function, and the simulation results are compared and analysed again. The results show that the parameters optimized by GA and BP algorithm are better than the original parameters. Further analysis shows that the parameters optimized by GA algorithm are better than BP algorithm in smoothness.