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The vertical stability coil is a new set of saddle shaped non-superconducting coil designed for the purpose of improving the control capability of plasma vertical movement. To avoid the electromagnetic shielding and en-hance the response performance, the vertical stability coil is installed in the inner wall of vacuum vessel. The subsequent disadvantage accompanying the benefit is that the coil is under severe neutron radiation. Besides the neutron radiation the coil will also encounter the ohmic heat once it is energized. The temperature rising of vertical stability coil is not allowed to beyond the specific threshold to guarantee the reliability of the coil com-ponents. Thus, the ohmic heat and nuclear heat calculation methods are presented and the detail temperature field is analysed by using ANSYS to check whether or not the coil can bear the thermal load. In addition, the thermal load will result in the thermal stress. To verify whether the thermal stress will lead to the structural damage, the thermal-structural coupling analysis is launched and the stress is evaluated based on ASME ana-lytical design. The analysis results will provide guidance for the local structural optimization of vertical stabil-ity coil.

This article deals with optimization of the truss structure. A genetic algorithm is used for this optimization. Within the strength calculation of the truss structure a normative assessment of the beam and their buckling stability is implemented. Also, the entire calculation is designed to use only standard profiles. In the first task, the optimization is focused on the weight of the structure, and in the second, on its price. There are also developments using different population sizes for individual cases, which will be described below. At the end of the work, a hypothesis is made for the link between price optimization and weight reduction.

The effects of strengthening phase in particulate ceramic composites on their properties were studied in presented paper. The experimental materials were a monolithic Si3N4 and particulate ceramic composites consisting of Si3N4 matrix with different additions of the SiC strengthening phase (10 and 20 vol.%). The microstructure, density, hardness and fracture toughness of Si3N4 + SiC ceramic composite materials were compared with monolithic Si3N4 based ceramic material. The addition of SiC particles into the Si3N4 based matrix does not positively influence the phase transformation from ?-Si3N4 to ?-Si3N4 in Si3N4 + SiC ceramic composite materials, but it affects the growth of prismatic ?-Si3N4 grains and contributes to the creation of fine-grained microstructure. The increase of SiC strengthening phase portion slightly increases relative density of Si3N4 + SiC ceramic composite materials. The hardness of ceramic materials increased from 14.48 GPa at monolithic Si3N4 ceramics to 16.99 GPa at ceramic composite with 20 vol.% SiC. The highest fracture toughness value of 8.30 MPa.m1/2 was achieved for monolithic Si3N4 ceramics, the lowest value of 7.09 MPa.m1/2 was achieved for ceramic composite with 20 vol.% SiC.

In the production of a new generation of customized implants, additive manufacturing (AM) is a hot topic. A titanium-based alloy, Ti6Al4V, is one of the most used materials for such applications with regard to its excellent biocompatibility and high mechanical properties which provide it with the capability to bear physiological loads. However, its resistance to wear is rather poor which might cause undesirable loosening of wear particles or even implant failure. Therefore, enhancing wear resistance is desirable. Thanks to a distinctive principle and rapid cooling, AM is known to be able to enhance mechanical properties. In this paper, we thus discuss tribological properties in direct relation to microstructures resulting from AM. We reveal the finest microstructural details of Ti6Al4V alloy prepared by different techniques of AM and discuss also the effect of heat treatment. Complex characterization including transmission electron microscopy, hardness measurement and ball-on-plate wear tests showed a mild contribution of AM to wear resistance of the Ti6Al4V alloy compared to the conventionally produced alloy.

At the present time, mechanical vibration is undesirable in many cases. Therefore it is necessary to minimize unwanted vibrations in any appropriate manner. This paper is focused on a study of factors influencing vibration damping properties that were investigated using multilayer composite structures. Frequency dependencies of the displacement transmissibility over a frequency range of 2?1500 Hz were determined by the method of forced oscillations. It was found in this study that the vibration damping properties of investigated multilayer structures are significantly influenced by number of material layers, excitation frequency of mechanical vibration, applied materials in multilayer structures, inertial mass, material thickness and density. It was also observed that a superior ability to damp mechanical vibration leads to a shift of the first resonance frequency peak position to lower excitation frequencies.

The conventional milling cutter design is based on a solid body. A cutter designed in this way has a guaranteed rigidity, but at the expense of tool dynamics. Computational methods of designing reduce the mass of a cutter in locations with lower stress density. This approach increases stiffness relative to the weight of the cutter. This paper analyses the benefits of modifications in the design of a lightweight cutter. The design uses an envelope of a con-ventional milling cutter that is filled by walls. Each modification changes the elasticity in different directions. These changes are monitored by displacements at the centre of the cutting inserts under load. Simulations confirm that even a small weight gain can mean a significant increase in tool stiffness.

This template describes the behavior of products created with additive 3D printing technology. The tested material used to produce the samples was polyactide acid (PLA). PLA is one of the most favourite material for 3D printing. This polylactide acid contains a metal additive. The standard dog-bone shaped samples reinforced with internal ribs arranged in a grid with 20% of the internal volume of the rib-filled sample were tested for tensile strength. The samples were subjected to different types of chemical degradation prior to the test. As a degradation agent, there was used an organic solvents. The result of the research is the effect of the degradation factor on the mechan-ical properties of these samples and possible use in practice, specifically in technology.

The paper deals with the determination of cohesive parameters of adhesive Scotch-Weld DP490 3M. Mode II of cohesive damage were examined. Experimental testing was performed on the test specimens to determine the me-chanical properties of the adhesive according to ASTM D7905. The results of the experimental testing were com-pared with the numerical simulation of the same test. The cohesive parameters of the adhesive were obtained from the numerical simulation. Cohesive parameters of adhesive can be used to design real complex adhesive bonded joints. Cohesive models (specifically cohesive contacts or cohesive elements) are one of the most accurate methods of modeling adhesive bonded joints, so this method is mainly used for parts where it is necessary to ensure suffi-cient strength, such as in automotive, aviation, etc.

The basic mechanical properties of structural materials (e.g. yield strength, ultimate tensile strength, uniform and total ductility, anisotropy coefficient, etc.) represent fundamental material characteristics. These parameters are mostly detected by a static tensile test. From the stress state point of view, it is therefore a uniaxial tension stress state. However, the service load usually means acting of wide range of stress states. For this reason, the department of engineering technology at TUL developed a device enabling loading the sample by planar bi-axial loading with the possibility to change ratio of their loading. It is therefore possible to load the material from uniaxial tension to equi-biaxial stretching. The aim of this paper is to determine the change of one basic material mechanical properties (yield strength) based on the adjustment of various stress states - from the conventional uniaxial tensile stress state (static tensile test) to equi-biaxial stretching. The own evaluation is performed on the measured stress-strain curves for the tested aluminium alloy AA6111. The results can then be used not only to describe the effect of stress state on the deformation behaviour of tested material, but can also serve as input data in numerical simulations of forming technologies.

A huge amount of waste comes into being from tyres which cannot already be used for their purpose. There are many ways how to utilize this waste but material recyclation is a priority. Waste tyre rubbers can be processed into a form of granulate which can be used into polymeric composite materials. This research deals with possibili-ties of tyre waste composite material utilization in areas distinguished for wear. The aim of the research was an assessment of a usage possibility of rubber powder (RP) coming into being from tyre recyclation process as a filler into a thermosetting matrix from firm Havel Composite applied into composite boards made by a vacuum infu-sion. The research focused on an evaluation of wear by friction against loosely fixed abrasive particles according to GOST 23.208-79, hardness and interaction of the matrix and the reinforcement by means of SEM analysis of the polymeric composite materials reinforced with waste microparticles arisen from tyre recyclation process. Research results proved a positive influence of the filler on the improvement of the wear resistance depending on the size of active rubber powder.

Q-P process is one of the latest techniques for heat treatment of high-strength steels with increased silicon levels. It is believed to be based on diffusion and migration of carbon between martensite and untransformed austenite, where the latter becomes enriched with carbon, and therefore becomes thermodynamically stable. However, the question remains whether much of the carbon partitioning in the Q-P process might be the result of the competing bainitic transformation induced by arrested quenching below the Ms temperature. This paper explores the use of dilatometry for identifying the products of austenite decomposition during Q-P processing of medium-carbon 42SiCr low-alloy steel.

Technology of adhesive bonding belongs to prospective bonding methods. The limit of adhesive bonds is cyclic loading which usually significantly decreases the service life of adhesive bonds and causes deformation of adhesive and cohesive bonds inside of adhesives. The article deals with the research of adhesive bonds exposed to cyclic loading. The aim of research was establishing an influence of the filler based on meshed coffee beans waste added into two-component epoxy matrix for bonding. The differences of mechanical properties of adhesive bonds with filler based on meshed coffee beans waste were evaluated at static and cyclic loading with 1000 cycles at first interval loading between 5 to 30% and second interval 5% to 70% of the static shear tensile strength.

Magnesium materials are interesting for application in medicine as biodegradable implants. There is an ef-fort to improve mechanical and corrosion properties for this application. Powder metallurgy seems to be a progressive method suitable for improving those demanded properties. Therefore, this paper deals with the preparation of pure Mg by extrusion of milled powder. The milling process should lead to better homogenei-ty of microstructure and the disturbing of the oxide layer on the powder particles. Also, the input deformation energy in the milled powder should affect the deformation and recrystallization process during extrusion. In this paper, the influence of extrusion temperature on microstructure, mechanical, and corrosion properties is evaluated. Higher extrusion temperature leads to the larger deformed grains in the extrusion direction and higher tensile strengths. On the other hand, the plasticity and compressive yield strengths are reduced with higher extrusion temperatures. Corrosion properties are negatively affected by the iron inclusions incorpo-rated in the structure during milling. Otherwise, corrosion resistance decrease with increasing extrusion tem-perature due to the grain size.

This paper investigates the influence of Artificial Neural Network (ANN) architectures on its prediction capability when machining nickel based super alloy. The ANN was employed to determine surface roughness parameter Ra through cutting conditions, tool wear and process monitoring indices such a cutting force components. The ANN structure was optimized by methods like a reduction of input vector parameters, dimensions of input data pattern, combined reduction and modification of hidden layers. Calculated and experimentally measured values were compared for each optimized ANN model. The work concludes that optimization of ANN has significant influence on prediction capability and accuracy for the task proposed.

These days are more and more posing claims for the highest quality of castings from the aluminium alloys and for the lowest weight of these castings. Thus for complex material (in this case alloy) utilization it is very important to monitor its behavior both during production (chemical composition, metallographic evaluation of the structure, observance of thermal treatments temperatures, refining and degassing of melt and so on) and also during its loading. This papers deals with the monitoring changes of stress on the testing samples surface arising from the force loading. As a loading there was a bending momentum at the testing samples (rods) from the alloy AlSi7Mg0,3 which was poured into the metal mould after the different thermal treatment methods. Bending momentum increased up to the expressive deformation of the tested sample. Results were also completed by the depth profile of the residual stresses which were measured by means of the X-ray diffraction (X-ray tensiometry analysis) namely for all thermal treatment methods. Moreover in the depth profile there was also performed the qualitative evaluation of the structure by the back-reflection Debye-Scherrer method.

The paper presents the evaluation of tribiological properties and condition of the tool steel surface for hot work 55NiCrMoV6 (WNL). Due to the fact that the steel 55NiCrMoV6 is used for components operating at high temperature, the tribological tests were performed at the room temperature as well as higher temperature (150 °C). The wear tests were performer with help of ball-on-disc tribotester, according to the standard ASTM G-99. The applied load was 5 N and 20 N. The counter specimen consisted of balls with the diameter of 6 mm made of steel 100Cr6. Steel samples 55NiCrMoV6 undergone thermal improvement. The average hardness amounted to 57 HRC. The test was performed with the slip speed of the friction pair 0.15 m/s and sliding distance 200 m. During the test, one registered the friction coefficient, frictional force, temperature and the depth of friction. Then, one calculated the wear rate for the friction agents. The evaluation of friction was performed after tribiological tests. For the load of 5 N the average friction coefficient in the room temperature amounted to μ=0.46. At the temperature of 150 °C it increased up to μ=0.69. The wear rate for the sample subjected to tests at room temperature was 3.618×10-5 mm3N-1m-1. At the temperature of 150 °C it increased up to 8.058×10-5 mm3N-1m-1. The maximum Herzian stress was 1.099 GPa.
For the load of 20 N an average friction coefficient at the room temperature was μ=0.69. At the temperature of 150 °C the friction coefficient was μ=0.57. The wear rate for the sample subjected to tests at the room temperature amounted to 2.136×10-5 mm3N-1m-1. At the temperature of 150 °C it increased up to 2.737×10-5 mm3N-1m-1. The maximum Herzian stress was 1.741 GPa. The wear of the steel 55NiCrMoV6 increased with the increased temperature. It has been confirmed by application of two different loads. The basic wear consisted in abrasive wear.

The paper deals with a study of actuator (brake cylinder) modification for generation of braking force in a brake unit. The original solution, carried out using the original brake cylinder in cooperation with the proportional pressure control valve, is sufficient in terms of correct function of the brake unit, but in terms of safety, the corresponding force sensor may be damaged in case of a control circuit proportional pressure valves defect. Another reason for the study is utilization of the total regulation range of the proportional pressure valve and improvement of the brake unit response time in case of braking force overload. Such overload results in tread or rotating rail surface damage. The article gives description of the currently implemented passive measures to increase safety against sensors damage, but also of proposed active measures to eliminate these defects by changing size and type of the brake cylinder.

In the report the results of bonded joints laboratory tests are published. The determination of the tensile lap-shear strength of rigid-to-rigid bonded assemblies according to the standard CSN EN 1465 (66 8510) was the aim of the carried out tests. The samples were made from steel sheets. For bonding of test samples four different types of adhesives were used (two super glue adhesives, one epoxy adhesive and one contact adhesive). Ahead of bonding the surfaces of all samples were blasted using corundum grit and degreased. For degreasing four various types of five different degreasers were used, namely perchlorethylene, acetone, methanol, technical gasoline and toluene. Then the samples were dried using warm air. For comparison the blasted samples without degreasing were bonded, too. At the tested samples bonding the consumption of adhesive was determined. From the adhesive consumption for one bonded joint and from the adhesive price the costs of one sample bonding were calculated. After curing the bonded assemblies were loaded using the universal test machine LabTest 5.50 ST up to their rupture. The rupture force was written down. From the values of the rupture force and the bonded surface size the bonded joint strength was calculated. By the carried out tests evaluation the influence of different degreaser types was determined. Also for all used adhesives the price of one bonded joint was calculated.

This study was focused on an effect of the plasma treatment on a mechanical behaviour of false banana's fibres (Ensete Ventricosum). The aim of the experiment was to describe the tensile strength of Ensete Ventricosum fibres which were modified by the plasma surface treatment. The fibres of Ensete Ventricosum, originally from Ethiopian region Hawassa, were used for this experiment. The fibres were prepared in the length of 100 mm. The samples were modified by the plasma treatment. Plasma was generated from a plasma generator (Plasma Reactor KPR 200 mm RM 54) while supplying the reaction gas (oxygen) and maintaining the reactor's pressure at 0.1 Torr with the use of a vacuum pump. To determine the properties that depend on the discharge power and treatment time, the plasma treatment was conducted in the power range 200-350 W for 10-50 s. The maximum tensile force was measured immediately after the plasma treatment to determine the ultimate strength. The ultimate strength and the deformation were determined by destructive tests using the tensile testing equipment (Labortech, MPTest 5.050, sensing unit AST type KAF 50 N, Czech Republic) with a rate of deformation 5 mm min-1. Fracture surfaces of fibres were studied using a scanning electron microscope (Tescan Mira 3, Czech Republic). The samples were covered with a thin layer of gold using a sputter coater (Quorum Q150R ES, United Kingdom) before SEM observation.

In order to enhance the stiffness of the gas film and increase the maximum speed of the rotor, this paper proposes an ultrasonic levitation structure with a cone type bidirectional supporting motor. The performance of the conical-type ultrasonic levitation support is analysed and tested according the relationship between the levitation force and levitation gap. Through theoretical analysis it is realised that the critical speed and vibration mode of the motor rotor is affected by the change of levitation gap in the ultrasonic levitation condition. The experiments with levitation gap and the maximum speed of the motor rotor show the structure can reduce the suspended gap, while simultaneously the maximum speed of the rotor is increased.

The paper deals with simulation analysis of a rail vehicle with a tilting bogie. The goal is to determine the wheel force in the rail-wheel contact and subsequently determine the safety against derailment. The rail vehicle model was designed in CAD program CATIA and imported to program SIMPACK with the RAIL module extension afterwards. Eight variants of different velocity, vehicle occupancy and setting of the tilting mechanism were analysed. The vehicle model was run along a track composed of straight sections and four succesive curves. Diagrams of the examined quantities icluding the lateral flanging force, vertical wheel load and the safety against derailment for the eight different variants make the result of the simulation analysis. Arising from the analysis, the biggest differences of results can be seen between the two variants of the highest speed but with different occupancy.

Resistance welding ranks among progressive and in practice often used manufacturing techniques of rigid joints. The basis of this method is in the utilization of the Joulean heat, which arises at the passing of current through jointed sheets at collective influence of compressive force. The aim of the carried out tests has been to evaluate the rupture force of spot welded steel sheets of various thickness using short-time spot welding and long-time spot welding. For test specimens welding the parameters recommended by the spot welder producer were used. After welding all assemblies were loaded using the universal test machine up to their rupture. The rupture force was written down. From the carried out tests it follows that welding of sheets of the thickness 1 + 1 mm, 1 + 2 mm, 1 + 3 mm, 1 + 4 mm and 2 + 2 mm the rupture force value differences of short-time spot welding compared to long-time spot welding are practically negligible. But at the specimens of thickness 2 + 3 mm, 2 + 4 mm, 3 + 3 mm, 3 + 4 mm and 4 + 4 mm considerable differences were determined. The part of this tests evaluation was also the assessment of the tested assemblies failed pieces.

This work aimed to characterise microstructure and mechanical properties of polymer composite samples. The main task was to adapt the well-known techniques of metallography (i.e. sample preparation and microscopic examination) to documentation of multi-component polymer materials and to optimize the methods of light and electron microscopy for this particular purpose. There were several issues (e.g. low melting point, absence of electrical conductivity), which made the process different from metal samples preparation and observation and which needed to be addressed. Various mounting resins were tested for the samples to find the suitable one, then the process of grinding and polishing was optimized and finally the microstructure was documented using light and scanning electron microscopy (SEM). Samples in the undeformed state were examined as well as the samples subjected to tensile test at different temperatures. Prior to the microscopic observations the material was analysed using methods of thermal analysis (TG A, DSC) and infrared spectroscopy (FT-IR). The tensile tests were employed not only to determine the mechanical properties but also to obtain deformed samples for further microscopic observation.

Hardness tests enable to determine one of the main mechanical properties of the material, namely hardness. For hardness testing, it is possible to use either conventional desk hardness testers or the currently increasingly used portable hardness testers. The paper is focused on determination of the accuracy and reliability of static (desk) and dynamic (portable) hardness testers. The paper deals with the measurement of hardness of calibration hardness plates by 4 different methods (Brinell, Vickers, Rockwell and Leeb) with using 5 different hardness testers (3 desk and 2 portable). The hardness values measured by the different hardness testers were compared to the reference hardness listed in the calibration hardness plates and consequently, the accuracy of these measurements was evaluated. The aim of the work has been to determine the accuracy and reliability of portable hardness testers in comparison with desk hardness testers.

An approach to increasing the efficiency of the diamond grinding of hard-working materials is shown. A well-founded choice of characteristics of the diamond-bearing layer of the tool can be made through analyzing the results of 3D modeling of the processes of formation and operation of the diamond-bearing layer and stresses upon it. Diamond wheels formed on porous ceramic binders are investigated and discussed.

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.

Vibrational properties of road vehicile are ussually evaluated according to two criterions, i. e. in terms of comfort for passengers and in terms of drive safety and roadway load. The topic of this article is focused on evaluation of passenger's ride comfort of a three-wheeled road vehicle. From the ride comfort point of view vertical vibration is decisive. Vertical vibration is given by obtained accelerations in given position on an assessed vehicle when it is driving on a road with various surface qualities within required time intervals. In the vehicle's design phase its vibrational properties are detected and evaluated by means of simulation computations on a virtual model. In our research we have assessed ride comfort of the three-wheeled vehicle, which were designed in our workplace. For purposes of dynamic analyses we have used multibody approach using Simpack software. The objective of this work is verification of the relevance of the current mounted suspension system for the greater driving speeds range of the three-wheeled vehicle and for different road qualities.

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.

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.

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.