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The automotive industry is one of the most dynamically developing segments of the industrial production worldwide. The introduction of still increasingly stringent emission limits for newly developed cars forces car producers to still reduce the fuel consumption of cars. One option is to use hybrid drive units in combination with a redesign of the automobile body while maintaining the highest possible level of vehicle safety. For these reasons, the automotive industry has been increasingly demanding to apply and process low density (lightweight) alloys, including aluminium-based alloys. These materials are subject to high demands both in terms of mechanical properties and technological workability in the mass production process. The utilization of mathematical modelling (numerical simulations) of production processes is now one of the standards in all phases of design and production the car-body and allows the implementation of variable designs in a relatively short time scale and the detection of potential production problems as well. In this paper, the influence of the kinematic hardening model on the accuracy of spring-back prediction is shown in comparison with the commonly used isotropic hardening model. For deformation analysis, a simple workpiece having ?U-shape? of EN AW 6111 material was used. Such aluminium alloys is used for production car-body panels in the automotive industry. Achieved accuracy of numerical simulation results is evaluated by the comparison shape obtained by numerical simulations and shape of experimentally bended workpiece.

Technological conditions of tube drawing influence the properties of the resulting products. In addition to mechan-ical properties, they also affect the geometry of the drawing tube ? macro geometry and microgeometry. The paper presents the results of measurements of macro geometry (roundness and cylindricity) and micro geometry (surface roughness) of the outer surface of the drawn tube. Tubes (STN 41 1353) were drawn through dies with different reduction angles (6° and 12°). On used fixed mandrels were ground the straight and spiral grooves. The effect of these grooves and hence the deformation itself has also been manifested on the outer surface of the drawn tube. On the measured roundness profiles are significantly noticeable places where the land and the groove were when drawing. This effect can also be observed on the deteriorated measured values of roundness. On the meas-ured values and roughness profiles of the outer surface of the drawn tube can also be observed the difference be-tween land and grove.

The paper reviews the results of an evaluation of the influence of the operating factors on traction-adhesive prop-er-ties of a locomotive. Planning of an xperiment was performed for two locomotives ?freight locomotive 2TE116 and shunting locomotive TEM103. The input for performing the numerical experiment was variation of 6 factors: the change in the wheel diameter of the first wheelset due to wear, the change in the mass of the locomotive as a result of the change in the amount of the fuel as well as the wheel rims wear, the impact of the friction damper in the primary suspension, change in the primary and secondary suspension stiffness due to operation. Regression equati-ons were obtained in code and natural form, which describe the effect of operating factors on the coeffi-cient of utilization of the locomotive adhesion mass.

The paper presents the results of an experimental research and a numerical calculation of a multi-gap seal of a centrifugal pump. The experimental research allowed to obtain the characteristics? performance of the multi-gap seal at different operating modes, in dependence on the axial size of the chambers, pressure distributions? changes, and a leakage from the seal. Using finite volume methods, values of radial hydrostatic forces, pressure distribu-tions and leakage values were obtained. The results of the numerical calculation were compared with the results of the experiment, which showed that they matched.

Zinc is one of the most promising elements for the preparation of biodegradable metallic implants. Despite low mechanical performance for load-bearing applications, the degradation characteristics of pure zinc belong to the best from all significant biodegradable metals (Zn, Mg, Fe). The enhancement of the mechanical properties is often reached using various methods of material processing, leading to grain refinement and subsequent enhancement of the mechanical properties. In this study, the microstructure, phase composition and the possible mechanisms of intermetallic phase formation in the ZnMgCaO alloy prepared by high energy ball milling and consolidated by extrusion were studied. Formation of the Mg2Zn11, MgZn2 and CaZn13 phases during the material processing was confirmed. The creation of the phases was, with high probability, significantly affected by the magnitudes of individual components of internal energy. The increment of the internal energy led to the formation of stable Mg2Zn11 phase as well as to CaZn13 formation. Based on our results and the characterization of the microstructure, the most suitable conditions for the preparation of a ZnMgCaO alloy were found.

This document presents the characterization of the dynamic mechanical properties of a racecar's frame. First, it introduces the applicability of modal analysis, then the modal analysis of a lightweight vehicle chassis will be detailed, which is the focal point of this paper. This analysis was performed to determine some of the modal parameters, in order to reduce the noise of the vehicle, the probability of a component failure and to improve the comfort. The simulation part of the applied analysis was based on dynamic FEM (Finite Element Method). The measurement part of it was based on measuring the FRFs (Frequency Response Functions), with the help of accelerometers fixed at the nodes of the frame. The excitation signals were provided by a shaker connected to the chassis. In order to provide good quality results, the processing and evaluation of the simulated and measured data has to be done properly, which is discussed in detail. However, one dominant factor of a modal analysis is to find the optimal measurement setup. For this reason, the details of the measurement setup will be included. Hence one of the goals was to improve the coherence curves of the FRFs. Thanks to the presented techniques, the coherence curves managed to be improved and the results of the simulation and the measurement were found to be in good agreement.

The work presents the computer simulation results describing the motion of the interacting particles in a vortex fluidized bed (the constrained motion). The data obtained reveal the peculiar features of the polydisperse system motion in the apparatuses with the variable cross-section of the workspace. The empirical coefficient determining the residence time of a particle in the vortex fluidized bed was calculated. An algorithm of the residence time cal-culations for a particle in the vortex fluidized bed under the constrained motion is developed. The results of com-puter simulation were a part of engineering (technological and constructive) algorithm of calculation for the fu-ture manufacturing of granulator?s industrial sample.

The authors presented paper deals with experimental measurement and evaluation of nanomechanical properties of hard turned and grinded surfaces on the cross section specimens made of the 33NiCrMoV15 steel. 33NiCrMoV15 steel was selected to perform for all realized investigations. Even before the start of the experi-ments that investigated the effect of hard finish turning against grinding, it was necessary to subject the investi-gated 33NiCrMoV15 steel to basic research with regard to its chemical composition, fundamental microstructure and basic mechanical properties. The microstructure was performed on Neophot 32 optical microscope. Chemical composition was realized on the spectral analyzer Spectrolab Jr CCD. Mechanical properties, like nanohardness H and reduced Young modulus Er were subsequently performed on the Hysitron TI950 Triboindenter with a Cube Corner measuring tip, and evaluated by software Triboscan. Based on the acquired values, a 2D nanostructure of the distribution map of s H and Er was then evaluated in Matlab. This scientific research, together with all measured and calculated values, is the fundamental that will help to optimizing the quality and used all these results to optimize presented material and technological processes in term of surface integrity.

In the recent years, the demand for weight reduction in modern vehicle construction has led to an increase in the application of hydroforming processes for production of automotive and aerospace lightweight components. The tube hydroforming measurement site (TH stand), designed and built at Warsaw University of Technology allows both die, and free tube hydroforming processes to be performed, thereby making it possible to obtain information about the material, as well as optimal process parameters [1][2]. The present freshly patented method for metal tube hydroforming is dedicated to short product series or even single products and prototypes [3]. The method is applicable to forming difficult-to-machine materials. The well-known techniques use dies made of plastic or wood, especially to form short product series. The use of moulding sand and properly prepared geometry of casting mould makes possible shaping materials at high temperatures, which could not be done in previous short series solutions, where a plastic or wooden die were used. [1] Sadłowska H., Jasiński C. Morawiński Ł., Strain measurements on the tube hydroforming testing machine, Archives of Metals and Metallurgy Vol. 65 , Issue 1, 2020, pp. 257-263 [2] Sadłowska H., Odkształcanie się rur podczas swobodnego rozpęczania hydromechanicznego na stanowisku TH, w: Prace Naukowe Politechniki Warszawskiej. Mechanika, Vol. 267, 2015, ss. 25-30 (in Polish) [3] Patent No. PL424401, Kochański A., Sadłowska H., Bulletin of the Patent Office of Inventions and Utility Models vol. 17_2019, pp. 11

The article deals with analytical and experimental solution of vertical oscillations of a mechanical system of bound bodies. The content of the article is to perform an analytical solution of the vertical oscillation of a system of bodies using the computer program MathWorks Matlab and MS Excel. Furthermore, an experimental investigation on a laboratory model of a mechanical system of the same parameters was proved. The aim of the work was to compare the analytical solution with the experimental method and to check the accuracy and applicability of analytical methods for the solved mechanical system.

Carburizing is used in applications where there is a high demand for surface hardness and abrasion resistance along with core toughness requirements. Carburizing is mainly used for parts which are subjected to abrasion, such as shafts, pins, gears, cams, etc. At the same time as the hardness of the surface layer increases, the fatigue limit of the steel increases after carburizing. The article deals with the evaluation of surface quality of carburized steels 16MnCr5 and 14NiCr14 in terms of surface texture change and dimension change after application of car-burizing. The analysed steels are used mainly in the production of gear wheels for gearboxes of wheeled, tracked and artillery. Furthermore, the coefficients of friction and wear were evaluated on these steels. The functional surfaces of heat-treated steels were analysed after grinding and after gas carburizing. The evaluation of the sur-face quality results in a deterioration of the surface roughness and an increase in dimensions after carburizing. The coefficient of friction after carburizing reaches a higher value compared to ground surfaces, while the coeffi-cient of wear decreases.

Trusses are commonly used structure in industrial buildings, warehouses, bridges, transmission tower etc. The analysis of the truss structure design is necessary in order to ensure stable and economical system. This paper presents application for computing planar truss structures that was programmed in environment of MATLAB App Designer using finite element method (FEM). App Designer is programming environment used for creating computing applications with graphical user interface (GUI). The created application for trusses allows users to create geometrical model of the truss structure and input material data, perform static analysis, modal analysis and to optimize truss structure in order to minimize its weight. To ensure accuracy of results, test calculations was performed using commercial software and compared with results from the created application.

The article presents the results of theoretical research on creating the mobile continuous earthmoving machinery. The aim of the article is to develop and evaluate the effectiveness of technical decisions when creating and mod-ernizing trencher chain and bar actuators. The peculiarity of the performed research is a complex way to solve the problems of ensuring the efficient operation of the earthmoving machinery. It involves a combination of two subsystems: "soil - operating equipment" and "basic chassis ? bearing capacity of soil surface". The mechanisms of changing the power parameters of the machinery load are established. The input parameters for a system de-scribing the operation of a special earthmoving machinery are soil physical and mechanical characteristics and the dimensions of the earth excavation, the installed power of the basic chassis engine, the type and characteristics of transmissions of the machinery operating equipment and chassis propulsion, geometric parameters of single cutters, the speed of cutting the soil and moving the machinery. The mathematical model of the system as a whole makes it possible to determine the rational design, kinematic and energy characteristics of the machinery and its operating equipment. It minimizes the energy intensity of soil development.

The objective of this paper was to investigate and respond to the quality and strength of CMT welds that were sub-jected to degradation effects and subsequently to tensile testing. The tensile test was recorded using AE acoustic emission. The experiment focused on the quality of CMT welds (Cold Metal Transfer) and the resistance of these welds to corrosion degradation. Welds are generally exposed to environmental influences such as high stress, stress and degradation effects. The combined effect of these factors may in some cases result in the destruction of weld joints. For this reason, emphasis is placed on the quality of welds and their resistance to environmental influ-ences. For this measurement there were ten samples prepared, divided into two groups, each having five samples. One group was subjected to corrosion degradation, while the other one was at the same time subjected only to envi-ronmental influences. Subsequently, all samples were subjected to tensile testing. The course of this test was rec-orded using the AE acoustic emission, where the AE sensor was attached to each weldment to record dislocations during the tensile test. Named values were evaluated in the Dakel–Daeshow program.

The subject of the article is a comparison of new and used powder for 3D metal printing. The powder is 316L stainless steel manufactured by Renishaw. The powder used was taken from the RENISHAW AM250 printer after use. Powder manufacturer Renishaw recommends using 15-45 micron powder in their 3D metal printers. An im-portant parameter of monitoring is the chemical composition of the metal powder and its changes during the thermal treatment during laser sintering. Another important parameter of a metal powder is its mechanical prop-erties, which determine the flowability, consistency and uniformity of powder application. By using an inert at-mosphere for sintering and storing the powder, these chemical changes can be prevented, especially against the formation of nitrides and oxides at elevated temperatures.

The article presents the results of experimental research on creating the mobile continuous earthmoving machin-ery. Methods for performing field experimental studies and measuring equipment used are described. The article shows the data of experimental research, their analysis, the determination of physical nature of changes in exter-nal load characteristics of the machinery operating equipment. The conducted experimental studies of modern mobile earthmoving machinery enabled to establish its technical capabilities, the characteristics of the power load of the operating equipment when developing the soil. It also enabled to determine the ways and directions for mod-ernizing the operating equipment of machinery. One of the ways is to optimize technological combination of soil cutting, displacement of the developed soil to the unloading area and unloading of the actuator. The research per-formed and the results obtained have enabled to experimentally confirm the effectiveness of the technical pro-posals to create the design of the chain and bar actuators with impulse soil unloading intensifiers for trenchers implemented in the industry.

Milling is one of the oldest methods of metal machining. This technology has been developed over a long time. The last milestone is the use of composite materials for the construction of cutting tools. However, there are other pos-sibilities for improvement offered by new production methods such as Metal Additive Manufacturing. The paper deals with machining experiments using a lightweight milling cutter with a lattice structure. The results of machin-ing are compared to the capabilities of a solid milling cutter. The evaluated parameters are: cutting forces, blade wear and surface roughness of the workpiece. Based on these parameters, it was not possible to confirm the benefit of the lightweight version for machining.

The aim of the article is to compare the experimental investigation of deflection of the sandwich composite beam with theoretical models. The experimental test specimens were composed of three layers. Skins were made using epoxy-resin-impregnated glass laminates with plain weave. The light weight foam Divinycell H100 was used as sandwich core. The three-point bending test was carried out. Fibre-optic strain gauges, SOFO SMARTape Compact deformation sensors, were used for determining the deflection of the sandwich composite structure. Experimentally obtained data were used for comparison with theoretical models – sandwich theory with the transverse shear, sandwich theory without the transverse shear, laminate theory with the transverse shear and laminate theory without the transverse shear.

The submitted paper describes the utilization of numerical simulations to predict sheet metal forming process of ultra-high strength TRIP steel HCT690T EN 10346. Numerical simulations of production processes are increasingly becoming an integral part of the pre-production stage of the sheet metal forming processes. Furthermore, it is possible to use these numerical simulations not only in the production itself (e.g. to test the validity of the process or influence of process parameters, etc.), but also in the post-production stage as a tool for various controls and comparative measurements with the real processes, testing the capacity of the process and so on. For proper and the reliable course of the numerical simulation must be at first obtained and then entered the correct input data into the numerical simulation software. This data enters into the simulation in the form of definition the material computational model. Such computational model is defined by using material data and individual material characteristics at different loading methods. With regard to the material model and the given process parameters, it is possible to realize the process simulation, which takes place in the numerical simulation software – in this paper was used PAM STAMP 2G from the French company ESI Group.

The presented paper deals with determination of mechanical properties of materials used for 3D printing (ABS, nylon and PLA). The theoretical part of the paper characterizes the static tensile test by which selected me-chanical properties of samples were evaluated. The practical part of the paper characterizes the additive technolo-gy Fused Deposition Modelling, by means of which standardized plastic samples were printed on the 3D printer. The practical part also deals with analysis of selected mechanical properties of samples made by Soft Tooling technolo-gy. SG 2000 and SG 145 polyurethane resins were used for the production of samples using Soft Tooling technology. Individual samples were analysed using selected tests (tensile test and hardness test). Surface integrity parameters were also determined for 3D printing test specimens. Parameters (tensile strength, tensile modulus, tensile strength and hardness) that were statistically processed were selected for each test. The paper is finished evaluating the re-sults obtained, which were compared with those given in the material sheets.

The aim of the study was to compare the strength of assembly joints of sleeve elements made of different structural, polymeric materials. Experimental tests were carried out to determine the mechanical properties of adhesive and welded joints. Adhesive joints were made of polyvinyl chloride pipes with the use of three types of adhesives: Epidian 53/PAC/100:80, Epidian 53/TFF/100:22, Vodaro 15010-VO. The welded joints were made of polypropylene pipes. All of the joints have been made with the use of a pipe fitting allowing for correct joints. Then the completed joints were subjected to destructive strength tests. The obtained results made it possible to carry out statistical analysis, which aimed at determining significant differences between the various methods of assembly. The tests carried out proved that the adhesive joints made with the Vodaro 15010-VO one-component adhesive were characterized by the highest strength - 2.30 MPa. The lowest strength was obtained in the case of adhesive joints made with Epidian 53/TFF/100:22 - 0.45 MPa epoxy ad-hesive composition. Statistical analysis showed that the strength obtained in case of adhesive joints made with epoxy compositions differs significantly from the strength of adhesive joints made with Vodaro adhe-sive. No significant differences at the assumed level of significance α=0.05 were also observed in the case of the strength of PP-R adhesive joints made with Vodaro adhesive and the strength of PVC-U welded joints.

The article presents partial results of research to increase the service life of snow ploughshares, which are used for winter maintenance of forest transport roads. The main working tool of vehicles - snow plough is the arrow ploughshare. It is made as a weldment. The contact tool, when in contact with the road, is the rake blade, which is subject to abrasive wear. The experiment consisted of analysing the current state of materials, designing and exploring such options that would ensure a longer ser-vice life of the blades. Welding material was designed to be applied to the base material of the blade. Furthermore, the HARDOX 450 was designed for the production of the whole ploughshare. The last design was welding HARDOX 450 with an electrode OK 48.00 with the base material steel 11 484. This proposal is presented in more detail in the article. The hardness of HBW, HV and HRC was measured on the samples and microscopic analysis was performed using light and electron microsco-py. The aim was to determine the quality of the connection of materials, mixing in the connection zone and comparison with the condition on the original blade. It is assumed that a suitable choice of welding electrode or a suitable choice of abrasion-resistant steel can achieve an effective increase in the life of the snow plougshare, whether from a technical or economic point of view.

Lower bracket is an important component in hydro generator. Taking lower bracket as the research object, the strength, the stiffness and the dynamic characteristics of lower bracket have been simulated and analyzed by means of establishing a finite element model. With the two design indexes of maximum normal stress and stiffness as the constraint conditions, aiming at an optimized design with the minimum mass and proposed a lightweight optimization method. The design parameters of the optimized model of hydro generator lower bracket are determined by using the compound form method with optimization iteration. Through lightweight optimization design, the maximum normal stress and maximum displacement of lower bracket are within the allowable value range, modal analysis shows that the dynamic characteristics of the optimized structure also meet the requirements, with the potential of material further utilized. The lightweight optimization design reduced the weight of lower bracket in hydro generator by 790kg and the weight-loss ratio reaches 44.38%, thus achieving the purpose of lightweight. The optimization results are applied in the improvement design of lower bracket and the method is practical and suitable for engineering applications.

Generative design is one of the most promising means of new product development in the world. It allows formation of organic structures that brings various benefits, e.g. in the form of savings of material and production costs. Generative design includes several types of technology, topological optimization included. The paper addresses the technology of topological optimization implemented on the support part of the 3D printing pad. The result of optimization is the creation of a new, more suitable design concept through the Altair Inspire optimization software.

This paper discusses the modeling and simulation results of a new multi-material for a cost-effective Selective Laser Sintering (SLS)-based 3D printer. As this technology utilizes several materials, the me-chanical property analysis of multi-materials is crucial for manufacturing an object with the desired physical characteristics. Firstly, the development of a database of the SLS 3D printing materials is ac-complished and based on the mechanical properties of materials, this optimization technique is proposed. Secondly, enhancement of physical property by stiffeners is considered and based on the stiffening tech-nology, and an alternative optimization method proposed. Finally, two different material minimization methods are discussed in this research. The first method is based on the embedded materials with desired mechanical properties for enhancing the mechanical properties of the printed objects, which are twice optimized by this method with increased material saving. The second method is designed to use stiffeners to improve the stiffness characteristics of the materials, and then, perform material optimization. This method is effective with more suitability to complex composite geometries. Thus, the methods help to reduce materials used as well as the production cost in 3D printing technology.

The main parameters of the hot forming machines are production capacity and the fatigue life of the used tools. The life of a tool depends on its shape and load. The load depends on the structural design and speed of forming. The goal of our paper is to present the structural optimization and technological parameters design with respect to tool life. This process is applied in the case of the hot forming machine analysis.

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.