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The article describes main possible usage of results of dynamic loading simulation with using of computational simulating system MSC. ADAMS. AVT and simulating computational model of track vehicle undercarriage. Main contens of article is the descripton of using of results for design value make-up file of changes of vehicle chassis parts and its new operating settings. The second described possibility of results simulation calculations usage is making - up of aproximate relations for transaction of fast orientation calculations. The next possibility of usage of simulation results is the possibility to verificate of mathematic model. The optimalization of influence changes of several design value together is last mentioned possibility of usage of simulation calculations results in the contens of this article.

Manufactures of automotive engines and complete vehicles strive for the lowest possible fuel consumption, which also leads to the use of motor oils with lower viscosity. Lower viscosity of oil reduces internal friction and provides faster distribution of oil into lubrication points, but simultaneously reduces the size of transmitted power. The design of automotive engines use plain bearings, which are based on aluminium, brass. Further are used steels with coating based on aluminium and bronze. The paper describes the impact of viscosity of motor oil to wear of basic materials, which are used in production of plain bearing. Reichert tester M2 for evaluation the lubricity from Petrotest Company was used in order to assess ability of motor oils to create proper lubricating film. Reichert tester M2 belongs to a group of equipments simulating real frictional contact. Stabinger viscometer was also used for the precise determination of viscosity of various types of motor oils.

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 current mechanical engineering is inconceivable without the implementation of CAx systems in design and manufacturing process of individual components. The automotive industry is a clear evidence of how CAx systems affect the innovation cycle of its product - a car. The innovation cycle in automotive was reduced from 8-12 years to the current 4-6 years. Even in this short interval automakers make some small design modifications called a facelift. Development in the automotive industry, therefore, is closely related to news and functionality CAx systems. CAD systems at the turn of the millennium are characterized as parametric graphic systems with a history tree of product creation. Parametric design implemented into CAD systems makes the model variable and open to rapid change management. The history tree in turn enables rapid editing and modification of forming or editing functions.

The paper describes the surface roughness measurement of functional parts of tools for minting coins. The coining dies were coated with three types of coatings - CrN, TiCrN and WC/C. Roughness of the coining die surface is a very important factor for the quality of a struck coin. The quality of specific coatings on the coining die surface was evaluated by a contact (Hommel Tester T500 roughness measurement device) and contactless method (microscope Sensofar PLu neox) by using optical interferometry and confocal microscopy. Results from the shop measurement gained by using the roughness measurement device were compared to the laboratory measurements gained by using microscope. Moreover, results were illustrated in the graph. Measured values were identical. Only the CrN coating showed bigger difference. Minimum roughness value was measured on the coining die with the TiCrN coating. The WC/C coating reached the maximum roughness value. 3D visualization method of surface roughness using software Gwyddion proved inappropriate for burnished surfaces.

The use of renewable energy sources in Slovakia is currently very debated issue. The main cause of this discussion is the increase of energy prices, which increasingly burden the population and companies. The use of renewable sources, including biomass, represents an important contribution to solve this problem. When new heat source is designed, several technical regulations and recommendations must be followed. The proposed device is intended to serve for combustion of biomass, in the form of wood, of pellets. The aim of this work is to describe the design process of the combustion device as the main source of thermal energy in our proposed micro-cogeneration unit.

Nowadays people spend still more of their life on the road. Vehicles has been becoming increasingly sophisticated and the main direction of their development is placed primarily into the areas of environment, design, safety and comfort. This work focuses primarily on the last-mentioned point, and that's seating comfort and the phenomena with straight influence on the transported persons. Probably with any of car elements, isn't the person in a direct contact to much as with the seat and therefore the seats and their innovation are still in considerable interest of the customers and manufacturers. This work deals with description of the resulting tensions and distribution of the specific pressures in the cushion of a car seat and also describe the creation of an appropriate computational model.
Based on the real transmission data, that was measured during driving a car, has been carried out an experimental measurements of static and dynamic loading of the overall stiffness and response of the system. Subsequently, depending to the real CAD data were compiled the boundary and materials conditions that describe the statical FEM model of the polyurethane cushion. For the quasi static load was carried out the experimental measurements on a mechanical pulsator, that is suitable for assessing the viscoelastic and hysteresis effects inside the materials. The found results have been verified with using the x-sensor on a model of real human back during the scanning of its specific contact pressure.

Hot tears represents serious defects, which are in most cases considered as unacceptable and may even result in disposal of final casting. The cause hot tear initiation is mainly a combination of several mechanisms (incorrect mold construction, chemical composition of used alloy, purity of used alloy, casting process conditions etc.). Basic principles of hot tears initialization can be considered relatively clarified, but a comprehensive and coherent view is still missing. The goal of proposed project was to design a coherent system to analyze emerging hot tears in the aluminum castings. The proposed mechanism is based on a number of concepts - a combination of "dog bone" and "T-section" tests. During the experiments will be possible to record the temperature at critical points, a tensile force in shrinking casting and by using heat-resistant glass placed above the heat node will be possible to directly observe the tears. Initial experiments will focus on verifying the functionality of the apparatus, the aim will be to analyze the impact of the solidification interval on hot tears.

Fiber reinforced polymer Resin matrix composites have the good performance, and it is widely used in various fields to release the impact load. Therefore, the study of stress and strain characteristics is quite useful to in providing the reliable basis for the structural design. The tensile test is one of the important methods to detect the mechanic property of the material, which can be used to observe the deformation behavior of the material. Reinforced materials are often added to improve the mechanical properties of the composites, and characteristics and mechanical properties of composite materials will be obvious anisotropic. Damage behavior of resin matrix composite material with fiber reinforced is complex, and mechanical properties of it are quite difficult to obtain just through the experiments, so the finite element method becomes a useful tool to get the mechanical properties. In this paper, we developed the conventional finite element method to investigate the mechanical properties of composites material. The verification proves that the modified finite element method can get much accurate results.

The article deals with the dynamic analysis of long freight wagon with a low and multifunctional loading plane for intermodal transport. The main task of simulation was to verify enough overlap of buffers, when the vehicle rides through S-curve, because the wagon is equipped with non-standard construction of the front part of undercarriage. Simulation was performed in program Adams, module VI-Rail. These and similar analyzes are nowadays an integral part of the development process of rolling stock and greatly reduce the time necessary for design, tests and certification of new vehicles. In the future, it will be possible in the case of verification results replace some real tests by simulation analysis on certain conditions.

In order to successfully acquire knowledge in area of machinery safety for engineering students it is necessary to adopt elementary principles associated with risk assessment. Identification of possible hazards is an important part of risk assessment and engineering students need to take part also in hands-on training to supplement their learning process. It is clear that one major obstacle to improve safety training is the problem of allowing learners to work directly with hazardous equipment. Traditional approach is based on the use of slide show presentations enhanced by animations or videos. This training method is passive in nature and does not allow for an actual realization of consequences resulting from ignoring safety practices during interaction between the student and the machine. In order to improve the educational practice in this context, the Virtual Reality (VR) technologies could be used. The purpose of this study was to conduct a preliminary investigation to determine whether training through VR simulator is comparable to traditional training in developing the skills necessary for performing identification of possible hazards related to lathe operation. The results of this preliminary study suggest that VR based training has the potential to constitute a valid alternative to the traditional training approach.

The main aim of this scientific article is to assess the contribution of surface layers by determining the experimental investigation and practical measurement of surface roughness Ra and selected components of cutting forces while external turning of AlCu3MgMnPb aluminium alloy. In these experimental procedures, a number of turning tests have been carried out by using a universal lathe machine tool and cutting forces and surface roughness scientific measuring devices. These realized measurements have been successively investigated and experimentally verified with the prepared trial samples. These presented experimental measurements describes the authors investigation of cutting forces while turning by the piezoelectric dynamometer Kistler type 5001 and surface roughness Ra with the Talysurf CLI 100 measuring device. This scientific article, together with measured and calculated results, is the fundamental that will help to optimizing the quality and used other technological and cutting parameters of turning technological process.

The physics features of the cutting process of ultrafine-grained metals produced by the method of severe plastic deformation are considered. The aim of the research was to evaluate, whether the grain size of titanium alloy has an influence on the characterization of chips, the cutting force components, the surface roughness and the microhardness in the cutting process. The experimental data of the machineability of titanium alloy Ti-6Al-4Mo with sub microcrystalline structure are presented in the paper. The features of the chip formation, the changes of the chip ratio and the components of the cutting force are examined. The main characteristics of the cutting mechanics are calculated and based on the experimental values. Also the experimental values of the surface finish roughness and microhardness are shown. It is established, that the change in the structure of the metal has an ambiguous effect on machineability by cutting. Further investigation of the machineability of metals with a submicrocrystalline structure will allow to choose the efficient mechanical treatment.

Machining has long been the most used technology in manufacturing processes. On the other hand, new materials are being developed or new ways of preparing them are being developed. One of such materials is High Speed Steel (HSS). The article deals with experimental study of a cutting tool durability prepared via powder and casting metallurgy. Durability of cutting tips produced from HSS Vanadis 30 (SN 41 9830) were tested during the short-term radial tests. Three modifications of the HSS steel were studied, while two types of them were prepared via powder metallurgy and the third one was made via casting metallurgy. The measured values were statistically processed and submitted to the remoteness testing according to Grubbs. The results have shown that the most appropriate material for production of cutting tips, ranked based on three studied steels from the durability point of view, appears Vanadis 30 produced via powder metallurgy alloyed by component Nb.

The focus at the outset was on nothing more than cryogenic treatment of cemented carbides. Then, in relation to additional findings arising from heating of cemented carbides, this paper was expanded to include the results of heat treatment and the behaviour at elevated temperatures. Although heat treatment is applied to diverse materials, no profound study of heat treatment has been dedicated to cemented carbides. This is despite the fact that both cryogenic treatment and heating to elevated temperatures have been proven to cause changes in their properties. Not all these changes are favourable. If precisely-defined rules are not followed, the changes may be adverse. The interest in heat treatment of cemented carbide has been very low. This paper not only provides comprehensive information on the properties of heat-treated cemented carbides but also presents the processes which take place in cemented carbides under load.

The paper deals with the proposal for the production of an assistance brake for a mechanical wheelchair, which will help the wheelchair users to move in the course of overcoming barrier-free and partially barrier obstacles. The introductory part of the contribution characterizes the basic requirements of the brake for a mechanical wheelchair, especially from a legal point of view and in terms of their safety. The practical part of the paper deals with the production of a prototype pair of assistance brakes in school conditions (workshop C2 of the Institute of Mechanical Engineering, Faculty of Mechanical Engineering, Brno University of Technology) using conventional machining technology (brake body production) and 3D printing technology (braking segment production). Part of the practical part also requires testing in typical / real wheelchair conditions. The contribution is completed by the technical and economic evaluation of the prototype pair of assistance brakes, which is related to the calculation of the total cost of their production.

Biological soft tissue is a non-linear and viscoelastic material and its mechanical properties can greatly affect quality of life. Many external mechanical factors can alter the tissue, for example the tissue of talipes equinovarus congenitus, also known as clubfoot, which is the most frequent congenital deformity affecting lower extremities with pathological changes of connective tissue. In clubfoot, the presence of disc-like mass of fibrous tissue, resembling intervertebral disc tissue, is described to be between the medial malleolus and the medial side of the navicular bone. The clubfoot tissue is often referred to be stiffer or rigid by clinicians, or it is referred to as contracted and less contracted tissue, however relevant evidence about mechanical properties is missing. Therefore, the description "disc-like" is informing only about relative mechanical properties of clubfoot tissue. We aim to prepare methodical approach to quantify mechanical properties of biological tissue with uniaxial tensile stress-relaxation test, in order to help clinicians and scientist to identify precisely the mechanical properties of normal and pathological tissue and their structural behaviour during mechanical testing. In this study, we test and tune the uniaxial tensile stress-relaxation test on biological tissue with high content of connective tissue such as collagen. The model tissue is porcine pericardium. The tissue has clear collagen fibres aligning parallel to the force applied. Modulus of elasticity measured here is comparable to other studies.

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.

Presented research paper is focused on the development of train front end cab, specifically on choice of material composition and production technology. Experimental part deals with a selection of the most appropriate multiaxial fabric based on its saturation by resin and type of polyester resin most suitable for low-pressure vacuum infusion. This technology is chosen with respect to dimensions of the part, resin savings (compared to hand lay-up technology) and also production cost of the cab. Prepared samples are evaluated regarding to the progress of production technology, part face quality (voids, dry spots, and delamination) and technological properties. As a result, optimal material composition for front end cab production is chosen and fabrication of prototype cab is conducted.

This paper enhances an innovative way of preparation of the composite materials by powder metallurgy. Magnesium-fluoride composite material prepared by spark plasma sintering exerted improved corrosion resistance. Magnesium powder was coated by boiling of Mg powder in concentrated NaOH and subsequent immersion in HF. Treated powder was successfully compacted via spark plasma sintering. The composite material with a continuous network of MgF2 is prepared and it exerts improved mechanical and highly enhanced corrosion resistance compared with the pure magnesium.

An intensive abrasive wear of agricultural machines and their parts occurs at the soil processing. An undesirable change of a tool surface occurs owing to the wear. Namely ploughshares of a plough are intensively abrasive worn. This undesirable change leads to a function loss. The paper deals with an evaluation of the ploughshare service life. The aim of the research was to evaluate the wear of the ploughshare with a layer of a carbide hardfacing OK Tubrodur 15.82 deposited on a bottom side of the ploughshare. The research was performed within a laboratory testing (a hardness HV30 and a wear) and field tests. Laboratory experiment results proved that the overlay material showed a significant increase of the wear resistance and the hardness. These conclusions of the laboratory testing were certified at the field tests. The research results certified this procedure as an efficient solution at the decreasing of the ploughshare wear at the ploughing.

Three low carbon steels with 1.5 and 3%Mn and either 1.5%Al or 2%Al were forged from cast ingots into bars using various heating temperatures and deformation conditions. Bars were heat treated by annealing at 950 °C to gain homogenized input materials for subsequent experiments. The effect of various austenitization temperatures and holds in the region of 800 -1200 °C was tested with regard to the final microstructure and hardness development. Hardness in the region of 320-550 HV 10 was obtained. The highest hardness was for all austenitizing temperatures achieved for 1.5Al3Mn steel and it decreased with decreasing manganese to aluminium content ration. This concentration ratio determined transformation behaviour and subsequently also formability of these three steels. Increase of this ratio to 2 for 1.5Al3Mn steel resulted in high tendency to cracking during forging at 1150°C and generally to the shift of phase transformations to lower temperatures and longer times.

A high performance of heat transfer fluid has a great influence on the size, weight and cost of heat transfer systems, therefore a high-performance heat transfer fluid is very important in many industries. Over the last decades nanofluids have been developed. According to many researchers and publications on nanofluids its evident that nanofluids are found to exhibit enhance thermal conductivity. The aim of this experiment was to investigate the change of workpiece temperature during drilling using Jatropha oil with nanoparticle and water with iron nanoparticle as lubricating and cooling fluids. These experiments were carried out with samples of nanofluid with different volume ratio. Samples JN1, JN5 and JN10 of iron nanoparticles in the base Jatropha oil with iron volume fraction 1%, 5% and 10% respectively. Samples WN1, WN5 and WN10 of iron nanoparticles in the base water with iron volume fraction 1%, 5% and 10% respectively. The work arises from the projects which were realized at University J. E. Purkyně, Faculty of Mechanical Engineering, in cooperation with Namibia University of Science and technology, department of Mechanical Engineering.

The requirement for high strength and ductility is usually associated with martensitic microstructure with a certain amount of retained austenite. One of the innovative heat treatment processes that can lead to such microstructure is the Q&P process (Quenching and Partitioning). It can produce microstructures consisting of martensite and a certain amount of retained austenite, which exhibit strengths above 2000 MPa and elongation levels of more than 10%. The objective of this research was to explore the effects of the cooling rate in the Q&P process and evaluate the effects of various microstructure constituents on mechanical properties of high-strength steels. Three newly-created experimental steels, which contained 0.43% carbon and had reduced Ms temperatures thanks to manganese addition, were subjected to several heat treatment routes which involved various cooling rates. The cooling rates were chosen on the basis of calculations using the JMatPro software and earlier results. It was found that by varying the cooling rate one can obtain various mixed microstructures and a wide range of mechanical properties. The strengths were in the range of 1200-2300 MPa and A5mm elongation levels were up to 18%. Because the amount of retained austenite has a considerable impact on the resulting mechanical properties, it was measured by means of X-ray diffraction.

The article focuses on the issue of the applied integrated resistance layers. Conductive layers are applied on the non-conductive material of cutting insert made from nitride ceramics. The layer is applied so that the cutting edge and adjacent surface create closed conductive circuit for each cutting edge separately. Throughout turning process come about wear of cutting edge and therefore wear of resistance layer. It results in decreasing of cross - section of resistance layer and increasing values of resistance. The records are carry out after individual cuts. The aim is to find the dependence between the course of wear and the course of electrical resistance during machining ductile iron EN-GJS-700-3.

The give paper is closely connected with the analysis of the normal force relating to the winding mechanism referring to production or manufacturing of raw tyres. The attention is mainly paid to the calculation of normal force during the manufacturing process when the individual constituents of raw tyre are pressed-in. The dynamic analysis as well as the calculation of the given normal force was done for raw truck tyre. The simulation of the movement and dynamic analysis for the given kinematic conditions as well as appropriate input values were solved in Solid Works - modeling computer program. Courses of normal forces for the first one set and the second one set of winding arms in dependence on lever position are in graphitic form. Based on the dynamical analysis, it can be concluded that, the second one set of winding arms does not have any influence on the quality of the produced car tyre.

This study analyzed the surface smoothness of some fuel briquettes produced from hazelnut, corn and sunflower residues. The residues were briquetted with different particle sizes (PS: 2-5 mm and 7-10 mm) under 80 MPa and 160 MPa. The surface smoothness of them were analyzed by image analyze from their high quality photos. In conclusion, it's seen obviously that the smaller particle sized briquettes had smoother surface than the ones produced with bigger PS. Furthermore, they had better results of compaction, toughness and physical properties.

Nowadays, 3D printing of metallic materials is a hot topic in many industrial spheres as it provides a one-step production of very complex parts. The additive principle based on processing of powders or wires in many successive layers minimizes material losses and so production costs. It also ensures great control over built shapes exactly according to computer-designed models. The most available technology is Selective Laser Melting (SLM) that uses a laser beam to selectively melt a metallic powder into the form of a desired product. The Electron Beam Melting (EBM) technology, that is based on a similar principle, is not so widespread, especially in the Czech Republic. Instead of a laser beam, it uses an electron beam. Related to that, EBM is far more energy-efficient and has different process characteristics. In this contribution, on the example of titanium alloy, we show marginal possibilities of this technology in the processing of bulk materials, from porous to highly dense.

The combination of steel and aluminum as a constructional material brings many benefits. Steel is characterized by strength and is suitable for components exposed to high stress. Aluminum is light and is suitable for less stressed parts. However, for technical and economic reasons, the arc welding of these materials has not been possible for a long time. The development of the technology that allows welding of steel with aluminum is linked to the requirements of the automotive industry. This is a process known as CMT - Cold Metal Transfer and refers to the low energy transition of the droplet during MIG/MAG welding. In this so-called "welding soldering", the base steel material is not melted, but merely wetted, whereas in the case of aluminum, a melt weld is formed. The advantage of this process is the lower heat input and consequently considerably less heat deformation. This paper deals with the analysis of the welded joint of the DX51D steel sheet with the Aluzinc layer and the AlMg3 alloy sheet made by CMT welding using the digitized inverter welding power from Fronius company. An AlSi5 welding wire of Ø 1.2 mm was chosen as an additive material. The used technology has led to the formation of a weld with a considerable porosity of the weld metal.

The paper deals with a machining of polymeric composite materials reinforced with fibres from hemp, false banana (Ensete ventricosum) and microparticles from Jatropha Curcas L. seedcakes by means of a technology using a water jet (abrasive water jet AWJ, water jet WJ). A matrix of the composite material is from a structural resin used for a production of sport equipment which shows good mechanical properties, but is it very brittle and it comes to its destruction during machining. Therefore, the water jet technology was used for the research. The research was focused on the evaluation of an influence of a velocity of a cutting head movement on a kerf width inlet and outlet the composite board by means of an optical analysis and on a connected quality of the cut. The composite material based on the biological reinforcement was cut by CNS cutting machine AWJ CT 0806 at a different velocity of the cutting head movement (traverse speed), i.e. 50, 250, 750 and 1000 mm/min. The research results proved a significant difference between the technologies AWJ and WJ and also among the velocities of the cutting head movement. The cut was inhomogeneous under unsuitable conditions and it came to a significant destruction of a surface outlet of the water jet.