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This paper deals with a synthesis of a new ionising radiation attenuation composite material from Lu2O3 - Bi2O3 nanoparticles structure, that has never been described yet. The paper describes the preparation of Lu2O3 - Bi2O3 nano- and microparticles by three methods: a self-combustion synthesis, a solid-state method and a coprecipitation method. Polymer solution was prepared from Lu2O3 - Bi2O3 nanoparticles and Polyvinyl Butyral. Afterwards, nanofibers were processed by an electrospinning method from PVB - Lu2O3 - Bi2O3 polymer solution. PVB - Lu2O3 - Bi2O3 nanofibers were characterised and their X-Ray attenuation effect was tested. This paper proceeds from one of the author’s bachelor thesis.

The design of the formwork support for a certain section of the Beijing subway project was carried out in this paper. And the disk lock formwork support was used in the engineering.It was analyzed on the the design of the formwork support for the roof with the thickness of 1.5m of the interval engineering. The manual calculation and the sap2000 finite element analysis were also used in the paper.The effect of the diagonal brace and its number were analyzed in addition to the design of the formwork support. It was showed that the axial force of the standing tube tends to be uneven with the increase of the number of slant bars in the framework. And the axial force of the standing tube connected to diagonal brace is larger than that of the framework without brace significantly. So it will be dangerous to the framework without considering the effect of it by the manual calculation.

Three cutting technologies, plasma, laser, and acetylene, were used to produce the same geometry of a hole with 33 cm diameter. The plates of the same steel St-37 (1.0038, ČSN 11375) with a thickness of 50 mm were used in all three cases and the aim of the work was to evaluate and compare micro-structure changes of the cut surfaces. Longitudinal and transverse samples were taken from all cuts for subsequent analysis. Light and scanning electron microscopy of surface and below-surface areas were carried out at all samples. Hardness profiles were determined by micro-hardness and nano-hardness measurements. Based on these results, the depth of material that was influenced by cutting was established by image analysis of light micrographs, micro-hardness measurement and nano-hardness measurement. It was found out, that all three technologies influence significantly micro-structure and surface hardness of cut steel. Acetylene cutting resulted in the deepest affected zone consisting of several layers with gradually changing microstructures based on various ferritic-carbidic morphologies.

Fast control coil is one of the most important components for EAST device to control the vertical stability of plasma. However, once the heating power of EAST is updated to 36 MW, fast control coil doesn't adapt to the new operation state and couldn't provide effective control for plasma vertical instability. Thus, insulation material with ITER-like magnesium oxide is developed to withstand high radiation and the coil position is also relocated to obtain more effective instability control. Given the relocation of fast control coil, electromagnetic load acting on coil-self and feeders are calculated based on elliptical integral and Ampere force law. The electromagnetic load as volumetric force is interpolated into the finite element analysis model to analyze the stress state on fast control coil. Finally, the design-by-analysis method is adopted to evaluate whether the stress could satisfy the specified acceptance criteria. The study will provide theoretical reference for the update of fast control coil from the perspective of electromagnetic load.

This paper aims at the problems of poor motion continuity and abrupt acceleration of small diameter deep well rescue robot in the process of motion characteristics analysis. According to the movement characteristics and structural forms of the grasping mechanism and bracket mechanism of the deep well rescue robot, the finite element analysis of the key mechanism is carried out based on Hyperworks-Optistruct solver, according to the analysis results, the specific parameters to be optimized are obtained. And the topology optimization of the key mechanism is carried out, the optimal design scheme of clamping mechanism and bracket mechanism of deep well rescue robot are obtained. The optimization results show that on the premise of meeting the strength requirements, the grid density distribution law is obtained. According to the variation law of lightweight curve, the overall weight of grasping mechanism and bracket mechanism decreases obviously. The whole optimization process is completed and the final optimization result is obtained.

This paper describes experimental measurements of travel rollers on a polyurethane thread. This exper-iment took place at the CTU Faculty of Mechanical Engineering in the laboratory of the Department of Design and Machine Parts. The experiment was performed within the project of a lightweight type of sampler, designed by a team of collaborators from our institute for OK Servis BioPro, s.r.o. For the new-ly designed type of sampler, it was necessary to determine the operation of a newly designed grain sampler. The load of the rollers is different in each environment. This paper presents the average values from the measurement, including its evaluation. Moreover, the paper compares different temperatures that can be achieved in the practice. Negative temperature values were not performed, as this meas-urement would be expensive and inefficient.

The article deals with the wear of the blades of the delimber device of harvester head. An input analysis of the materials of the fixed knife and movable arm parts was performed. It consisted of chemical analysis, evaluation of microstructure and hardness measurement by HRC and HB methods. The original welded joint was analyzed, which ensured the connection of the blade and the fixed, resp. movable arm mechanism. Based on the findings, two blade replacement solutions have been proposed. The first was the application of hard metal by an OK 84.58 electrode and second use HARDOX 450 by welding with a fixed part or a mechanical gripping with screws. This was recommended based on previous research at the Faculty of Technology. The hardnesses of the original blade material were compared with the proposed solutions. The correctness of the proposed methods will be verified in the future and in operation.

The effects of punch radius, deep-drawing speed and amplitude on the friction coefficient were studied on an improved drawing-bulging friction coefficient testing device on basis of ultrasonic vibration. A contact friction model based on the tribology theory of adhesion and plowing was constructed and used to explain the friction reduction phenomenon of applied out-of-plane normal vibration. The results show that the friction coefficient decreases with the increase of ultrasonic vibration amplitude. At the same deep-drawing height, the friction coefficient decreasing rates at amplitude of 7.8um and 10.1 um on the deep-drawing speed of 0.1 mm/s and 10 mm/s, were 6.7% and 18.8%, respectively. the friction coefficients at the punch radii R0.3 and R1.5 declined from 0.18 to 0.13 and from 0.12 to 0.11. The friction coefficients of thin specimens were larger than thick specimens whether ultrasonic vibration was applied or not. The average friction coefficient from theoretical modeling (μ_v) was smaller than the friction coefficient without ultrasonic vibration (μ_0), and the relative friction coefficient ratio declined with the rise of amplitude and was inversely proportional to time.

Hard-to-machine materials conclude a variety of materials. In this group of materials are high-strength, hardness-resistant steels, such as austenitic steels, but also non-ferrous alloys with high cor-rosion, heat resistance and strength based on nickel, titanium or cobalt, etc. For machining of these materials, it is necessary to choose suitable tools. The improper cutting tool can cause an increase in geometric inaccuracies, rapid wear, etc. Cutting material is an important factor during designing of cutting tools. A combination of a proper cutting tool with the trochoidal milling can reduce maching time, extend tool lifetime and reduce production costs.

High deposition rate with minimal heat input is one of the primary emphases in wire arc additive manufacturing. This study aims to determine the optimal input parameters of micro plasma welding for single-layer deposition. The stability of a single layer is crucial as it serves as the foundation relative to the deposition of layers to avoid a discontinuous multi-layer material. The study focuses on wire feeding speed, welding speed, and pulse and their interaction between the input and response variables. Based on the study, the regression equation between the three key parameters and the response using the Box-Behnken Design response surface methodology was proposed. The outcome demonstrates that the op-timized sample deposition produces a smooth surface appearance with no apparent defects.

The issue of accident analysis in relation to railway vehicles of urban mass transportation is highly accentuated at the moment. In terms of designing the frontal area of trams, adequate attention should be paid to the optimal front end design in order to reduce the risk of pedestrian injury. The properly used shape and materials can minimize the consequences of the pedestrian’s contact with the vehicle, or the eventual dragging of the pedestrian under the vehicle. For the front end to be tested and optimized, it is necessary to develop and validate a pedestrian model for performing calculations even in the design preparation stage. From a historical perspective, impact tests and pedestrian protection were not paid significant attention. There should also be a methodology for data collection and evaluation across the public transit company. The data collected within the Czech Republic is inconsistent and hard to analyze. At the beginning of our research, we addressed the question of which dummy configuration with respect to the tram is most appropriate for our crash tests.

The paper presents the results of experimental work on the assessment of 3D geometry of surface stereometry obtained as a result of Water Jet (AWJ) water-abrasive beam cutting using an Eckert Opal WaterJet COMBO hydro-abrasive cutter. Studies of geometric structures were conducted using the Alicona Infinite Focus microscope. The article analyses selected spatial roughness parameters of the multilayer structure surfaces combined as a result of the vulcanization process with an aluminium alloy surface. The results of the research work are summarized in the technological function of the WJ cutting conditions, such as the cutting speed and the mass flow of the abrasive material.

Nowadays, the tendency to survey and accelerate technological processes in order to increase produc-tion efficiency on the one hand and to reduce the ecological impact of production on the environ-ment on the other hand is increasingly prevailing. These aspects encourage both the applilcation of mathematical modelling of production processes and utilization of new material types ensuring suffi-cient strength and ductility while reducing the overall weight of the final asembly. This paper focuses on investigation and evaluation of the mechanical properties of the material under plane shear stress conditions. Specifically, it concerns the testing of a dual-phase high-strength steel DP500 (designa-tion according to EN 10346) having structure based on a ferritic-martensitic matrix. The test material is loaded by means of a testing machine with a continuous static load and condition of the plane shear stress is achieved due to the geometry of the test specimen (ASTM B831). In the experimental part of this paper, plane shear tests are performed to determine the basic mechanical properties and stress-strain characteristics of the material with respect to the given loading conditions. These deter-mined parameters and material characteristics can be further used as important input data to improve results of the numerical simulations regarding the aspect of metal forming technologies – basically stamping process.

The continuous development of construction due to the great needs of society and industry, the need to build newer and more durable buildings have meant that scientists all the time look for new opportunities to improve the quality of materials used in this field. Above all, concrete, as material commonly used in construction, has been the subject of research for many years in order to improve the properties. Already in antiquity there were the first attempts to modify the building material with fibers. Initially, they were organic fibers. However, the first patent dates from 1874, when A. Bernard patented the idea of strengthening concrete with steel filings [1]. Then, attempts were made to strengthen the concrete with long steel fibers, which was done by H. Alfsen in 1918. Further researches led N. Zitkiewic to test the strength and impact toughness of concrete with the use of pieces of mild steel wire [2]. Steel fibers in concrete were used for the first time by Romuladi and Baston in 1963. In the paper a comparative analysis of selected mechanical properties for concrete and fiber-reinforced concrete, e.g. compressive strength and Young's modulus, was presented. It was checked how the value of Young's modulus and the compressive strength of concrete change depending on the content of steel fibers. Three types of samples were tested: 1 - concrete, 2 – fiber-reinforced concrete containing 0.25% of steel fibers, 3 – fiber-reinforced concrete containing 0.50% of steel fibers. As the analysis has shown, the greater number of steel fibers is not directly proportional to the increase in its compressive strength or the value of Young's modulus.

The article deals with new types of coatings and their mechanical properties. CTRN and CRONAL are newly developed coatings intended for active parts of forming tools. Their behavior and mechanical properties are still under investigation. Coatings are used for functional components in various areas of industries, their de-velopment is constantly in process. The aim of the study and the experimental solution provides a compari-son of the mechanical properties of the new coatings with the well-known coatings DLC, TiN and TiSiN. The aim of the work was to perform an analysis of CTRN and CRONAL coatings and compare their me-chanical properties with other coatings. We chose the methods of nanoindentation, hardness measurement, scratch test and layer roughness. The results will allow easy determination of the proper coating for a suitable material. The results present the specific functionality of the individual coatings.

The article deals with a possibilities of an enhancement of functional properties of highly stressed components by specific combination of surface technology. Two surface technologies such as plasma nitriding and laser shock peening were selected for the experiment. Those technologies were applied upon steel 42CrMo4 frequently utilized in manufacturing of strained components. Properties obtained by applied surface technologies were tested by following experimental methods. The chemical composition was verified by optical emission spectrometer Tasman Q4 Bruker. The surface morphology was inspected by scanning electron microscope TESCAN MIRA 4. The microstructure of heat treated as well as of nitrided specimens was observed by opto-digital microscope Olympus DSX500i. The microhardness profiles were measured by microhardness tester LM247 AT LECO. The friction coefficient was tested on tribometer Bruker UMT 3 TriboLab. For an assessment of the surface wear resistance the profilometer Talysurf CLI 1000 and Contour GT were utilized. The experimental results show that although the proposed surface technology combination manifests itself to be disadvantageous, both technology LSP, as well as plasma nitriding, applied separately, can lead to a significant wear reduction.

This paper describes some tools usable for quality control in plastic injection moulding. The introductory part presents tools for quality management, the use of which is demonstrated in the next part using a practical example. The selection of suitable methods was based on proven methods for quality management. They were selected to work in synergy. The author's contribution is the modification of the PDCAI method, which was enriched by another step, namely, innovation. The last part of the article presents is a demonstration of FMEA, Ishikawa diagram, and Pareto diagram.

The quenching and partitioning (Q&P) process is an advanced method of heat treatment of high-strength steels. The resulting properties of Q&P-processed steels are dictated by their microstructure which consists of tempered martensite, fresh martensite and retained austenite (RA). These phases arise from individual steps of the Q&P-process. An important step is stabilization of retained austen-ite because RA raises ductility to above the levels found in conventional steels upon quenching and tempering. If the desired stability of RA is to be achieved, Q&P processing must not initiate compet-ing processes associated with carbide precipitation or austenite decomposition into bainite-like mi-crostructure. Yet, it appears that the very decomposition of austenite into bainite is an accompanying process that takes place at the partitioning stage, the stage which plays an important role in terms of mechanical properties of Q&P-processed steels.

A crane bridge is a dominant component of all bridge crane. It is imperative to pay attention on its strength features and go through a strength analysis. The introductory part of this paper points out characteristics of a bridge crane, mainly a crane bridge and materials used to produce the crane bridge, namely S235 structural steel. The paper set out the strength analysis of the main girder of a single girder bridge crane model in the means of comparing analytical and numerical solutions. The calculations take into account the load of the main beam in its centre according to the standard STN 27 0103. The bridge crane model is designed for a 500 kg load carrying capacity. The numerical solu-tions are represented by finite element method (FEM) analysis in Ansys software. The intention is to determine the deformation of the main girder depending on the weight of a load and a hoist, to de-termine the maximum deflection and resulted bending stress. Furthermore, one of the purposes is to create the precise 3D CAD model of the main girder. The 3D CAD software Catia V5 was used to design the bridge crane model. The strength analysis of the main girder of IPE 100 profile was performed by the FEM analysis using the Ansys software and by analytical calculations. The results ob-tained by the computing software Ansys were only slightly smaller in comparison with the analytical calculations. Results obtained by Ansys can be considered as more accurate. It can be concluded, such the designed and strength-checked main girder can be in the future put into a production.

Today, the emphasis is on the production of materials that are degradable in nature and on produc-tion with modern technologies. In order for these materials to find a suitable use, they need to be exposed to the conditions that may arise in the application. The effect of degradation was assessed for composite materials with a PLA matrix and a natural-based filler, which were processed by 3D printing technology. The progress of degradation in the climate chamber was monitored over a peri-od of 6 weeks. The results are determined by static tensile test and hardness test and the difference in weights of the test bodies. The test results confirmed. During the degradation process, the test spec-imens with natural fillers deformed less than the specimens made of pure PLA. The maximum ten-sile strength values for the material with natural fillers were approximately two thirds lower than for pure PLA. The maximum tensile strength during degradation showed an increasing or stagnant ten-dency. the maximum elongation decreased during degradation for the material with fillers showed a logarithmic behavior compared to pure PLA with a linear tendency.

The third generation aluminium-lithium alloy AA2050 finds wide applications in defence and aircraft industries by virtue of its high strength-to-weight ratio and excellent corrosion resistance. Friction stir welding (FSW), relatively novel technique, is more suitable to join this alloy compared to other conventional fusion welding techniques. In this work, the overall quality of the weld joint was decided from the higher values of tensile strength, yield strength, percentage elongation, hardness of weld zone, hardness of heat affected zone, bending load and lower value of width of heat affected zone. The optimal (combined) design was used to design the experiments with four numeric factors (traverse speed, rotational speed, tilt angle and shoulder diameter) and a categoric factor (tool pin profile). The multi-response optimization problem was reduced into a single-response optimization problem using grey relational analysis (GRA); principal component analysis (PCA) was used to assign optimal weighting values for the responses in the process of dimensionality reduction. Mathematical model for the reduced single response, which can be perceived as overall weld quality, was developed by the response surface methodology (RSM) and the optimization of process parameters was also carried by the RSM. Analysis of variance (ANOVA) was carried to evaluate the significance of each parameter on the overall weld quality and the adequacy of the developed model. The confirmation tests conducted at optimum levels of parameters proved the effectiveness and robustness of the method.

Selective laser melting (SLM) technology has strict demand to its powder materials which is needed to be spread evenly and conducted laser sintering layer by layer. Therefore, the uniformity and flatness of powder bed are the basic conditions for processing. Ball milling is an important composite powder preparation process of SLM. Three kinds of ball milling processes, dry ball milling, wet ball milling and hollow milling with various parameters are adopted to prepare TC4 / TiB2 composite powder. It is concluded that a balling time 8 h at a speed of 230 rpm without milling ball is proved the optimal working condition to make the composite powder maintain good spherical shape and ensure the mixing uniformity. The mechanism of three kinds of powder mixing effects is revealed by analyzing the dynamic relationship and hardness of the milling ball, TC4 and TiB2 particle. This work provides an important reference for the preparation of high quality TC4 / TiB2 composite powder for SLM.

Aiming to study the influence of ultra-precision grinding parameters on the accuracy between the same clamping method and different workpiece sizes. This paper mainly analyzes the difference between the measurement precision of different parts by the same measurement method and the measurement precision of the same parts by different measurement methods. Therefore, the influence of grinding parameters on grinding precision is reflected. For the same part, it is concluded that the coaxiality error coincidence degree at end A and end B reaches 90.32% and 95.27%, respectively by using precision three-coordinate measuring instrument and Mahr roundness instrument. The coincidence degree of end A and end B verticality error reached 97.54% and 91.08%, respectively. For parts with different sizes, the Mahr roundness meter is used for measurement. The analysis shows that the coaxiality coincidence at end A and end B is the highest, reaching 98.36% and 92%, respectively. And from the analysis, the errors are mainly reflected in the factors such as jig and fixture and grinding process.

Nowadays the electromagnetic induction quenching approach has been widely applied in the surface treatment process, especially for the parts made by metal materials such as the crankshafts. In this paper, quantitative study was adopted in researching the strengthening effect of this technique. First the multi-physics simulation was achieved to carry out the key information caused by this approach such as the temperature and residual stress distribution property. Then the fatigue limit load prediction was conducted based on the simulation results and the theory of critical distance. Finally corresponding experimental verification was performed to check the accuracy of the predictions. The results showed that the combination of the critical point method and the Goodmen mean stress model can provide highest accuracy in the prediction. While for the critical line method, the Gerbera mean stress model is the most suitable choice.

The presented article deals with the determination of selected mechanical properties of additive ma-terials used for 3D printing (PETG, PLA, ABS, ABS +, PLA ESD, ASA, PC / ABS). Due to the fact that 3D printing has exploded over recent years and additive manufacturing has become popular in some industries, the quality of input materials and their mechanical properties is extremely im-portant. We used 3D printer Original Prusa MK3 to prepare samples for testing. Individual samples printed from all above mentioned materials were analyzed using selected mechanical tests (static tensile test, hardness tests). In the static tensile test, selected parameters (tensile strength limit, ten-sile modulus, elongation) were determined for all additive samples, which were statistically pro-cessed. The parameters for two methods of measuring hardness were also statistically evaluated, namely Shore and ball indentation. All tested additive materials were compared with the aim of ob-taining the final ranking (point evaluation of tested materials with quantification of price costs). The best properties after the performed tests were achieved by the additive material PLA Filament Plasty Mladeč.

This article deals with the calculation of pressure vessels for beer maturation using analytical calcula-tion according to ČSN standards and with the help of commercial software PVESS. The article pre-sents commonly used procedures in the design of pressure vessels, resp. vessels for use in the brewing industry in the assembly of pressure vessels stacked on top of each other. The article describes the main parts of the brewery tanks, including the procedure for their design. The choice of materials used, the choice of basic dimensions of pressure vessels was determined in the work. The tank vessel is made of stainless steel 1.4301 or 1.4541. The advantages of this material in the brewing industry are also presented. From the given input parameters, a control calculation of the strength of pressure vessels was performed. The result of the work was the verification of the calculation, finding out the deviations of the measurements using mathematical software with a common calculation according to the valid standards for the calculation of pressure vessels.

The constantly developing aerospace industry places demands on increasing productivity and produc-tion efficiency. At present, new construction materials are being produced that have better physical and mechanical properties than conventional materials. In addition to new materials, new cutting materials and new machining technologies are being developed. The combination of suitable machin-ing technology, material and tool will achieve excellent product surface quality, long tool life and thus production efficiency. Due to its mechanical and physical properties, technical ceramics can be used in the machining of difficult-to-machine materials, in which there is mechanical stress on blows, impacts, abrasions and other damage. Thanks to these properties, ceramics as a material is very suit-able for the production of machine tools. The presented article deals with the applicability of ceramic milling cutters in high-speed machining of nickel alloy, which is used mainly in the aerospace indus-try. The evaluation of the experiment took place by means of DoE - analysis of cutting forces, the result of which is the creation of the dependence of cutting forces on cutting conditions. Based on the data obtained, it is possible to continue to further intensify the cutting conditions in the area of high-speed machining.

The article is devoted to the influence of mold filling parameters by the HPDC - High Pressure Die Casting method on the mechanical and structural properties of castings intended for technology and mechanization means in forestry. Three groups of AlSi10MnMg alloy samples were formed for the experiment. Three different settings of mold cavity filling parameters were chosen. Two castings were made from each setting. Two samples were taken from two places on the casts. Thus, 12 pieces of samples were used for the experiment. An analysis of their mechanical properties was performed using a static tensile test. tensile strength, yield strength and ductility were evaluated. The microstructure was evaluated by light optical microscopy. The influence of process parameters on the quality of the casting was monitored from the point of view of the occurrence of errors, defects and the method and size of the exclusion of structural phases. The experimental results showed that the best results were obtained when the process parameters of the first group of samples were set. Their values are the closest to the customer's requirements.

The surface created by machining significantly affects the service life and functional reliability of the component. As part of this study, four different chip machining technologies were evaluated on the surface texture of the polymer material Ertacetal C. The samples were processed by turning, milling, grinding and polishing technologies, 5 samples for each technology. Within the given technology, different cutting conditions were chosen to compare the effect of cutting conditions on the resulting surface roughness. The machined surfaces were comprehensively evaluated on the basis of 16 profile and surface roughness parameters due to the practical use of the tested material. Surface texture measurements were performed on a Talysurf CCI Lite device. A non-contact method using a coher-ence correlation interferometer was used for the measurement. The obtained data were evaluated using TalyMap Platinum software. Graphical documentation of the machined surfaces was made using an Olympus DSX500 opto-digital metallographic microscope.

The study is focused on the dynamic response of the head and thoracic area of an anthropomorphic test device (ATD) during low-impact collisions with a tram. Two collision scenarios were analyzed: the frontal impact (a chest as a primary contact area) and the side impact (a thigh as a primary contact area). The measurements used a pedestrian dummy (Hybrid III 50th percentile male dummy, Jasti Co., ltd., Tokyo, Japan) and a unique pendulum impact testing machine (impactor) of own design. The crash tests were conducted at various impact intensities (velocities) into the chest and left thigh of the dummy. The primary outcome variable was a resultant magnitude of acceleration measured in the area of thoracic vertebra Th5 and on the vertex of the head. The differences between both areas of interest were analyzed as well. The results provide the analysis of the dynamic behavior of the head and chest of the dummy at low impacts, the validation of the impactor for crash-test analyses, and a possible way to verify the use of the dummy in similar experimental settings.