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This article deals with a non-destructive experimental method for determination of modulus of elasticity of hydraulic hoses. There is described experimental equipment for determination of the modulus of elasticity of hydraulic hoses by expansion method. The modulus of elasticity is determined for several hydraulic hoses of different parameters on basis of combined hydraulic capacity of oil and hose. Furthermore it is necessary to know oil bulk modulus. The modulus of elasticity of hoses is very important during design of a hydraulic system. It is necessary to take into account the modulus of elasticity of hoses in a mathematical simulation model of dynamic parameters of a given hydraulic system. A designer can subsequently utilize maximal flexibility, maximal stiffness or required ratio of the mentioned hose properties. The measured hose isn't destructed and can be subsequently used in hydraulic systems. It is a big advantage of this method.

The article deals with the evaluation the state of 120 mm mortar projectile stabilizer. It assesses a crashed projectile, whose stabilizer got stuck in the barrel during the shot. The evaluation includes the analysis of the mechanical properties, especially hardness, besides the evaluation of cracks, structure and chemical composition of the materials used. Cracks are documented with Olympus GX 51 optical microscope and Tescan Vega TS 5135 electron microscope. The chemical composition was assessed by EDS method on the Noran System Six/300 device. The hardness values of the stabilizers were obtained by LECO LV800AT hardness tester, the microhardness measurement used LECO LM247AT equipment. Material properties and microstructure evaluation was compared with the documents available in the metallurgical laboratory of the Department of Mechanical Engineering.

The paper deals with a design and construction of an implant prototype of a knee-joint femoral component with a complex shape mathematic description especially of functional (articulating) surfaces. The core of a technical solution labours under the thought of casing of femur distal part with a shell of certain thickness whereas a special area is used as a referential area defining an inner and outer shape of the shell. The area is marked, cropped and smoothed. It is the created area of the lower end of the patient femur respecting the overall curvature of the knee joint.
Within designing of the implant prototype of the femoral component of the knee-joint modern methods of getting CT data, their processing by CAD software called CATIA and subsequent post processing are applied.
The prototype implant of the femoral component of the knee joint is designed from processed CT data of the patient affected knee-joint (the femur distal part, a tibia proximal part). The 3D model of the implant prototype of the femoral component is created on the basis of data editing in CATIA software. The final 3D model is then located to the composition (a bone, the implant prototype) and using anchoring ribs it is fixed on the femur distal part.

Spatial measurement and evaluation of the surface profile parameters provide valuable and useful information about the relationship between the geometric characteristics of the surface and its functional properties. Evaluating the structure of surface area may help to explain a variety of problems in manufacturing technologies as it allows detailed quantitative study of geometric and dimensional changes of the surface profiles. AWJ cutting still generates unrevealed questions regarding interactions of the cutting material with the work-piece. The article presents experimental study of surface of steel material after AWJ cutting with usage of optical method that was selected as universal method that overcomes some of the shortcomings of contact methods.

The simple geometry was investigated by analytical simulation in the article. The cylinder cross flow and heat transfer was evaluated. The different Nusselt number equations obtained from literature were mutually compared. The selected range of Reynolds number was from 5 to 2.106 with respect to laminar and turbulent regime of fliud flow. The coefficients of Nusselt number equations were also compared with respect to Reynolds number ranges. The Sieder-Tate correction for thermal boundary layer was taking into account and its effect on the Nusselt number values was also evaluated. Differences in result of selected equations are presented. Sieder-Tate correction effect is also discussed. However the equations were applied in its validity intervals of Reynolds and Prandtl numbers, the high differences up to 40 % from each other were found.

The article deals with cyclical abrasive wear of the surface of forming tools. At this stage the research focused on the genesis of stress in the contact between a deformed material and a tool in the cold bulk forming process. The experiments were conducted in the simple configuration of the upsetting test. The article presents the results of abrasive wear by a combination of materials of examined samples and upsetting plates. The abrasive wear in the used material specimens was analysed comparatively in the form of the wear factor by the finite element method. Two intersecting phenomenological fields represent the output for the examined material combinations. Firstly, it is a formulation of the dependencies of the maximum depth increase of the surface wear. The argument is the number of exposure cycles. At the same time, the topology of degradations and the resulting roughness in the space of the exposed surface were examined.

The article is aimed to the development of homogenization procedures for fibers reinforced composite materials. The development of these procedures during the homogenization was performed by using a representative volume element (RVE). Two RVE versions were developed, hexagonal and square fiber arrangement. Both modules are automated and have been developed in the Python programming language with connection to FEM software Abaqus, which serves as a solver, and post processor. Afterwards the assembled modules follow homogenization of particular composite structures, which results are in a comparison with result gained from other homogenization methods (analytical methods for homogenization of composite materials) are processed into tables.

Corrosive attack of metals and alloys by molten glass can be described by parameters of surface roughness. Fractal geometry and statistic tools were used for surface roughness quantification. The obtained parameters of fractal geometry and statistics were determined on boundary curves between alloys and glass which had been generated from the digital photography of sample cross-section. This methodology was successfully used for quantification of surface changes of iron aluminides Fe-14Al-6Cr and austenitic steel during corrosion test in molten soda-lime glass at 1200°C.

The aim of the research was to analyze the delivered profile samples, where appeared the darker spots with an irregular circular shape on the surface of light colored profiles after process of natural anodizing without colouration. Profiles are manufactured with alloy EN AW 6060 (AlMgSi) according to EN 573-3, which was carried out by heat treatment hardening. For material were performed measurements of Brinell and Vickers hardness, Vickers microhardness and substructural analysis in occurrence area of the dark spots and outside of these spots (light area of profile). Based on these analyzes it revealed significant difference of mechanical properties in these individual areas and different substructure of the solid solution α there. Based on knowledge of heat treatment technology is this substructure heterogeneity and diversity of mechanical properties (hardness and micro-hardness) of the given alloy caused by uneven localized cooling after solvent annealing in the hardening process. The occurrence of inhomogeneities is then right to express to different color profile to the surface after the anodizing process.

The results of an experimental study on influence of cerium addition on structural characteristics of 42CrMo4 steel are presented. Alloying with cerium was carried out using profile filled with powdered mixture of mischmetal. The samples were taken from two ingots cast in the VHM's steelworks with standard time of casting of about 14 minutes. Three steel bars from one of the produced ingots were prepared by forging. Chemical composition, macro- and microstructure, X-ray EDX chemical microanalysis, hardness of the all steel samples were obtained. Cerium addition resulted in the formation of micrometer size inclusions which can be utilized for controlling the grain size structure of steel castings. The majority of the particles have settled at the bottom part of the casting, indicating that the convection flow during solidification was very weak. The cerium addition slightly diminished hardness of the steel. A segregation phenomenon causing inhomogeneous distribution of cerium over entire volume of as-cast samples after relatively rapid crystallization process of the steel was revealed.

Nowadays, one of the motive trend in engineering industry is transportation and manipulating technology. The hydrostatic mechanisms belong to the most important components and are created by hydraulic engines, pumps, switchgears etc. Inseparable part of hydraulic engine is a servo-valve which coordinates the fluid flow by a microscopic movement of piston. The servo-valve is a casting, usually made of ductile cast-iron that is necessary to machine. The functionality of hydrostatic circuits is influenced significantly by the precise movement of pistons.Therefore it is necessary to provide the dimension accuracy, machining quality and also the geometric shape of holes. This article describes the issue of holes reaming in hydrostatic components with a use of reamers made of sintered carbide and cermet.

This paper reports on doping with the catalysts consist of rare metal compounds like Co₂B, La(NO₃)₃, Ce(SO₄)₂, Ti(SO₄)₂, CeCl₃, LaCl₃ and mixed catalysts for improving hydrogen release capacity of NaBH₄. The results show that the hydrogen generation volume (HGV) is about 10ml and the hydrogen generation rate (HGR) is very low when doping with La(NO₃)₃, Ce(SO₄)₂, Ti(SO₄)₂, CeCl₃ and LaCl₃. Comparatively, Co₂B presents favorable catalytic effect on hydrogen generation properties of NaBH₄. The study on the mixed catalysts find that the HGV of the samples doped with mixed catalyst of Co₂B and Ce(SO₄)₂ is the largest. Among all doped samples, the HGV of sample doped with 5Co₂B\2Ce(SO₄)₂ is the largest about 317ml. Compared to all samples doped with mixed catalysts, the samples doped with mixed catalysts of Co₂B, Ce(SO₄)₂, Ti(SO₄)₂ and CeCl₃ presents the best properties of hydrogen release. However, compared to Co₂B, doping with other catalysts makes the hydrogen release time of NaBH₄ longer. Overall, NaBH₄ doped with the mixed catalysts of Co₂B, Ti(SO₄)₂ and CeCl₃ present the optimal HGV and HGR than doped with any other catalysts.

This article describes the effect of selected parameters of plasma nitriding on the change of dynamic parameters of steel DIN 1654/4. Plasma nitriding is currently used in a wide range of technical applications such as a final operation to improve the mechanical properties of components. This experimental investigation is devoted to the analysis of the influence of plasma nitriding on the notch toughness of structural steel DIN 1654/4 (CSN 41 2042.4). The test of the dynamic fracture behaviour of structural steel was carried out using by instrumental Charpy hammer on the plasma nitrided specimens with V and U notch, manufactured according to standard CSN ISO 148-1. The plasma nitriding was implemented at 500 (°C), process duration t = 10 and 20 (h) and variable gas mixture ratio of 24H2: 8N2 (l/h) and 8H2: 24N2 (l/h). The test results showed that nitrided steel has become more brittle. However, it was found that for different gas composition, the notch toughness has behaved quite diversely. The values of notch toughness of steel in case of gas ratio 8H2: 24N2 (l/h) were decreased but for gas ratio 24H2: 8N2 (l/h), with extension of time, the notch toughness was slightly increased.

Grinding is currently still an important method for surface finishing. At FPTM JEPU is realized the research, which deals with this issue. There are carried out experiments with grinding various materials under different conditions and then are evaluated the selected components of the surface integrity, which are generally roughness Ra, Rz and Rz, material ratio curve (Abbott Firestone curve) and also obtained roundness. This article deals with grinding nickel alloy Inconel 718, when selected cutting grinding conditions were used and subsequently the surface roughnesses Ra, Rz and Rt, the surface profile and the material ratio curve were measured and evaluated.

3D printing technology has recently extended to metallic materials and allows now to produce 3D models directly from metallic powders. There are several methods of 3D metal printing, such as Selective Laser Sintering (SLS), Direct Metal Laser Sintering (DMLS), Electron beam melting (EBM) or Selective laser melting (SLM). Compared to conventional technologies of casting, forging and machining, these methods offer many advantages. The most important is shape variety allowing preparation of very complicated shapes and designs, which would be impossible to reach by classical techniques. Moreover, there is practically no material loss, since the remaining powder can be recycled and reused in other manufacturing processes. That is one of important cost savings. However, for now, the metal 3D printing is unable to compete the price of large-lot production. In present paper, it is demonstrated that by the SLM technology it is possible to achieve comparable material properties of stainless steel AISI 316L as by conventional technologies and therefore, this method offers a suitable alternative.

This paper is aimed at chemical-heat treatment of a selected material. The plasma nitriding layers were applied on the 41CrAlMo7-10 steel. The influence of plasma nitriding parameters on the thickness and microhardness of nitrided layers were investigated. Plasma nitriding was performed at 500°C with a mixture atmosphere of H2 and N2 in the plasma nitriding equipment. The pressure of plasma nitriding process was determined to be 280 Pa. The period of the plasma nitriding process was changeable from 5 to 30 hours. The microstructure and mechanical properties of the nitrided layers were studied by using GDOES spectrometry, optical microscopy, and hardness testing. The depths of the plasma nitriding layers were also estimated using cross-sectional microhardness profiles. Microhardness and surface hardness of mentioned samples were significantly increased. The measurements have shown that the period of plasma nitriding process has a significant influence on the depth of nitriding.

The nickel base superalloys are progressive group of materials designed especially for application where others materials does not fit with its mechanical properties (such aluminium or copper alloys) or corrosion resistance at high temperature nor heat-temperature properties (such iron or steel). Their unique properties comes from solid solution gamma, where after precipitation hardening a various phases - γ' (gamma prime), γ'' (gamma double prime), δ (delta), different types of carbides (MC, M23C6, M6C, and M7C3) with various degree of coherency to matrix are presented. Article gives a brief description of such phases with its affect to mechanical properties.

Nanomaterials are advanced materials exhibiting unique mechanical, chemical and physical properties due to their structural constituents having size less than 100 nm. Such materials are suitable for using in wide field of possible applications e.g. special structural applications, catalysis, biomedicine or electronics. There are many methods how to produce nanocrystalline materials or nanoparticles including vapor, liquid and solid processing routes. In this work, ultra-high-strength nanocrystalline silver was prepared by combination of selective leaching and subsequent consolidation by spark plasma sintering. Conventional cast silver was used as reference materials.

Pressure die casting of metals is a method of precise metal casting, where molten liquid metal is forced under high pressure into a mould cavity. Requirements of engineering and automotive industries for perfect castings with smooth surfaces, exact dimensions and thin walls determine the nature and direction of development of pressure die casting of metal. This article analyses the possible causes of a foundry defect - short run - generated during casting based on varying technological parameters.

Laser Shock Processing (LSP), or strengthening the material surface by laser shock wave is very modern and progressive technique, which allows a significant increase in fatigue life of cyclically loaded parts. The compressive residual stresses are generated in the surface layer of material processed by laser beam, which can significantly improve the fatigue properties of the material and reduce the initiation and propagation of the surface cracks. This technique finds practical use of the most demanding applications like in the aerospace industry. For this reason, we are mapping the selected surface properties after the laser treatment for the better understaning of technology possibilities. After that another suitable applications can be found. It is also important to determine appropriate parameters for different types of material and requirements affecting the result.

Cutting tool wear monitoring is one of key problems in automation of machining processes. Apart from the cutting tool wear monitoring for the cutting tool change and cutting tool failure, cutting tool wear monitoring may be one of the components for the adaptive control of a machining process. This paper is focused on the design of turning cutting tool wear sensors of the system flap - jet principal with increased extend. On the geometric principles in cutting with a turning cutting tool, the relations among the output of jet mouth, clearance angle and cutting tool wear were expressed. Two variants of turning cutting tool sensors were designed and experimentally verified. The results of experiments have proved the possibility to apply cutting tool wear sensor of the system flap - jet principal with increased extend in practical use.

The paper deals with the issue of magnetism and its use in mechanical engineering as well as in other industries. Transmission systems are rather frequently present in almost every technical system. The purpose of each transmission system is to transform energy, based on which its quality can be assessed.
The main objective of this paper is the structural design of a magnetic cycloid gearbox, a detailed description of transmission kinematic analysis, elaboration of calculation models for FEM analyses consisting of the analysis of gearing power relations and calculation of maximum torque the gearing is able to transform.

Alloys based on the intermetallic phases are presently considered to be very promising materials for demanding technological applications in a wide range of industries. The biggest disadvantage of intermetallics is their low toughness at room temperature. One of the way how to increase their plasticity and eliminate susceptibility to low temperature brittleness is preparing intermetallic phases with ultrafine grain structure. The paper describes the preparation of ultra-fine grained alloys based on intermetallic phases by mechanical alloying and subsequent compaction by the "Spark Plasma Sintering" (SPS). Influence of the individual alloy components on the preparation and mechanical properties of intermetallics alloys were studied. The basic mechanical properties at room and elevated temperatures, resistance to high temperature oxidation and thermal stability of alloys were measured.

The trend towards using turbochargers in various engines continues. In some applications, including engines of light duty trucks, city buses and even tractors and harvesters, the warranty of long life is demanded because turbochargers are subject to high cyclic loading and on consequence the turbochargers can determine the lifetime of the whole engine. The replacement of the aluminium compressor wheel for a titanium one significantly improves the turbocharger lifetime, but since a titanium alloy has about 60 % higher density than an aluminium alloy, the mass and the moments of inertia of the wheel increases, which further leads to changes in natural frequencies, rotor stability and power losses in bearings assuming the same bearing system as for the rotor with the aluminium wheel is employed. In this article the influence of the increased mass properties are discussed. AVL EXCITE and in-house developed model are used for the construction of Campbell diagrams and stability maps and for the obtaining of detailed information about the behaviour of the oil films in floating bearings.

This article is deals of noise and vibration measurement of rollers for belt conveyor. In the first part of article a stand measuring is described and individual rollers types which were measured. There are five types of rollers for measurement. The first type are the Transroll rollers which were measured with the rubber pads. The second type are the Transroll rollers again. The third type are the Sandvik rollers and the fourth type are "Italian" rollers. Process of noise and vibration measurement of the individual rollers types is given. In conclusion of this article is noise and vibration measurement evaluation. Compared of the Transroll roller with pad and without pads is given. Three the highest acceleration values in depending on the frequency of vibration in individual directions (x, y, z) are given.

In the field of designing of new or renovating the existing rail vehicles the iussue of individual structural units lifetime is currently appears increasingly coming to the fore for the vehicles long-term operation. On one hand, modern tools of virtual reality allow performing stress analysis of structures, most frequently using FEM, on the other hand, there is software designed for multibody system assembly intended for the evaluation of rail vehicles dynamic properties. Flexible bodies' implementation into a rail vehicle multibody system considerably extends the possibilities of computer simulations of rail vehicles running. In this paper we present inclusion of a flexible body into a multibody system of a rail vehicle bogie. We chose a freight wagon bogie for the purposes of modelling and simulation. Parameters of the fright wagon correspond to a Y25 bogie. Simulation calculation of the bogie running on the track have been performed using a track model consisting of two reverse curves.

The paper describes the flow measurement in an aneurysm model by PIV (Particle Image Velocimetry) and PLIF (Planar Laser Induced Fluorescence) method. The velocity field and the concentration were determined for four steady and one unsteady flow regimes.
The area of the main flow and the area of liquid circulation in the region of the bulge were defined on the basis of velocity field measurement. Mean concentration of dye was evaluated in three areas: the entry to the model, the bulge of aneurysm and the outlet of the model. Concentration in course of time and residence time of dye are discussed on the dependance of unsteady flow.

Article deals with the detection of reduced stress in a braked railway wheel based on thermal transient analysis on virtual models, because they influence the characteristics of the railway wheels. Structural analysis was performed by means of the ANSYS Multiphysics program system package. Thermal transient analysis deals with the detection of temperature fields which are result of braking by brake block. The applied heat flux represents the heat generated by friction of brake block. It is applied to the quarter model because of the acceleration calculation. This analysis simulates two braking with subsequent by cooling. Distribution of the equivalent stress was detected in the cross section railway wheel, at selected points. The input parameters were used from the thermal transient analysis. These equivalent stresses result due to thermal load.

The most widely used technologies of founding Al-Si cast alloys are gravitation and semi-centrifugal casting, casting under pressure and so on. The contribution deals with influence of different casting method on changes of Fe intermetallic phases. Casting into metallic mould and sand mould were used for experimental work for comparison Fe-rich formation. Fe is a common impurity that leads to the formation of complex Fe-rich intermetallic phases. The dominant phase is plate-shaped Al5FeSi. These phases are unwaited, because reduce properties of aluminium casting. The experimental materials have most common addition Mn. The addition of Mn may reduce Al5FeSi phase and promote formation Fe-rich phases Al15(FeMn)3Si2 in "skeleton like" or "Chinese script" form. This knowledge was confirmed. The present study is a part of larger research project.

Thesis is interested in accurately detect moisture inside of plaster moulds, that will be measured by microwaves apparatus. Part of the thesis is also construction and assembly of the stable apparatus, so that it is possible to monitor the effects of microwaves on a plaster sample, then evaluate the moisture content of the sample and compare it with the weight test. The actual moisture measurement will be performed in several ways, such as by measuring the reflection or attenuation of electromagnetic waves. The result of this thesis will be a graphical representation of moisture to measurable variables relationships, gained from the microwave apparatus.
Plaster moulds are quite known, but casting technology requires from plaster moulds not only dimensional accuracy after drying, but as well surface smoothness, resistance to cracking upon drying and sufficient strength and breathability, or minimal gas evolution during casting. The presence of water during the casting process is not very welcome phenomenon. It is therefore very important to set correctly dry form, otherwise it may happen that the moulds can be during casting destroyed, or cast alloy can create a casting bubble by the influence of moisture in the form. That means discarding of the products.