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  • Improving of Geometric Precision in the Manufacture of Circular Holes Using Technology WEDM
    238-245
    Views:
    198

    WEDM technology is among the final technology. It is characterized by the high quality of the machined surface. Therefore, a small geometric deviation from the desired shape, position, orientation or run out may have a significant impact on the functionality of the finished component. Its range is largely influenced by the accuracy of the applied electroerosion device, the precision of the workpiece and tool setting, the machining method, but also the combination of each other and the adjustment of all process parameters. They result in the final quality of the machined surface not only in terms of roughness parameters but also in terms of geometric precision of the machined surface. The aim of the paper was to describe the possibilities of improving the geometrical accuracy of WEDM with thin brass electrodes. At the same time, it contributes to an existing database of knowledge that defines the influence of selected aspects on the geometrical accuracy of the machined area in the production of circular openings.

  • Safety Index Based on Geometric Probability Is Proposed to Represent the Uncertainty of Soil Parameters for Spread Foundations
    43-52
    Views:
    108

    The overall factor of safety in geotechnics can be defined as the product of four partial factors of safety. One of these partial factors represents the uncertainty of the soil parameters. Based on geometric probability, a safety index is proposed to calculate the uncertainty of the soil parameters for spread foundations. Numerical examples have also been presented.

  • The Role of the Geometric Transformations in ihe Formation Process of the Function Concept
    324-336
    Views:
    121

    The concept of the function and the different geometrical transformations play important role in the technical sciences. Since geometric transformations are functions, so-called geometric functions, therefore, in this study, we present a possible way of that, how can we apply the animations of the geometrical transformations which are made with GeoGebra in the formation process of the function concept in the primary and secondary school level.

  • The CAD Modelling Possibilities of Gear Pairs by Two Ways in the Mechanical Engineering Practice
    205-219
    Views:
    129

    The GearTeq 2021 software is a complex gear designer software which is capable to design different types of gears based on the initial geometric parameters by the user. Naturally, the users’ appropriate knowledge for the gear theorem and the manufacturing technology is indispensable for the design. The possibilities of the software are shown in this publication. The designed gear pairs are usable for different engineering fields (robots, working machines, vehicles, etc.).

  • Surface Quality of Carbide Metal After Electrical Discharge Machining
    31-38
    Views:
    103

    Recently, the requirements for machining shape-complex products made of hard-to-machine materials, including carbide, have been increasing significantly. However, their machining is rather problematic. Additionally, a high-quality standard of the machined surface is generally required, not only in terms of roughness but also in terms of the geometric accuracy of the machined surface. All this while maintaining a high level of economy in the machining process. However, meeting these demanding requirements in real technical practice is not always an easy task. Moreover, in combination with modern machining processes, only a limited number of production technologies can meet this requirement. Therefore, due to the high demands placed on today's modern production and the required high standard of the machined surface, progressive EDM technology is increasingly finding its application. And it is through this progressive technology that it is possible to achieve relatively good success in carbide machining. The aim of this paper was therefore to describe in detail the results of an experimental investigation aimed at identifying the quality of the machined surface achieved in terms of the roughness parameters of the machined surface in the electrical discharge machining of selected types of carbides using a wire tool electrode.

  • Influence of MTP on Surface Roughness and Geometric Accuracy of Machined Surface at WEDM
    91-97
    Views:
    108

    Electrical discharge machining technology is one of the most precise machining methods. Therefore, even the smallest deviation of micro and macro geometry generally has a significant impact on the overall quality of products produced by this progressive technology. The quality of the machined surface after Wire Electrical Discharge Machining (WEDM) is influenced by a large number of factors, most of which are influenced by the Main Technological Parameters (MTP). The aim of the paper was to describe the results of experimental research aimed at assessing the impact of MTP for WEDM on the quality of machined surface in terms of geometric accuracy and roughness parameters Ra and Rz. The samples were made of high alloyed ledeburitic chromium-molybdenum-vanadium steel designated EN X155CrVMo12-1 on a Sodick AQ535 electroerosion machine. The tool used was a standard compact brass wire  0.25 mm with the designation Elecut Brass CuZn37.

  • Mixing Power Requirement Determination in Agitated Drum Using Dimensional Analysis
    76-88
    Views:
    136

    The mixing of granular materials in an agitated drum can be characterized by the dimensionless power equation. The equation was created by dimensional analysis, for which the parameters affecting the mixing power requirement were collected based on the literature. The most important of these are the rotational speed, the drum loading factor, the geometric and physical properties of the mixing drum and the granular materials.  The dimensionless power equation is used to estimate with reasonable accuracy the Power number within the given range of applicability , which has been validated by measurements. From the Power number, the mixing power requirement of the mixed granular material can be calculated, which can be used as operational data for selecting the mixing motor.

  • Efficiency of the Machining Process of Circular Shapes by Electrical Discharge Technology
    53-61
    Views:
    90

    Due to its high machining precision, EDM technology is nowadays very important in the production of high-precision parts for various industries. The high precision of the machined surface in combination with the ability to machine circular surfaces brings, in addition to several advantages, some negatives. The most significant negative of this machining technology is the relatively low productivity as well as the overall production efficiency. The latter is affected by many accompanying phenomena. The main accompanying phenomenon that contributes to the decline in the overall economic efficiency of EDM is the microgeometry errors that occur due to the non-homogeneity of the EDM process. Another accompanying negative phenomenon is the geometric accuracy errors of the machined surface, as a consequence of systematic destruction of the wire tool electrode, faulty interpolation in its guidance, and, last but not least, its vibration. These aspects consequently lead to the requirement for multiple applications of additional finishing cuts, which significantly reduces the overall economic efficiency of the machining process. Therefore, the experimental research aimed to search for options that can effectively help to achieve higher productivity but especially the overall economic efficiency of the machining process.

  • Implementation of the Heinrich Spatial Visualization Test in a Virtual Environment
    1-8
    Views:
    197

    A virtual environment was developed for PC and Android to be used with a desktop display and the Gear VR, respectively. The goal with it is to measure and enhance the spatial skills of people, because the latter can be achieved by solving simple geometric problems. Originally, this virtual environment consisted only of three such tests, namely the Mental Rotation Test, Mental Cutting Test and Purdue Spatial Visualization Test. Measurements were done in the past with these tests, but now the Heinrich Spatial Visualization Test is also included in the virtual environment. In this paper, its implementation and future measurement plan are presented.

  • Frequency Domain Analysis of Tractor Tyre Enveloping Properties
    223-229
    Views:
    77

    Main source of vibration excitation for off-road vehicles are ground profile undulations. Most unprepared terrains are characterized by wavelength of unevenness that is of the order of magnitude of the contact length between tire and ground, so that, due to its shape and elasticity, tire actually behaves as geometric low-pass filter transforming real road profile geometry into effective vehicle vibration excitation. Since this effective profile represents real vehicle excitation, it is of interest to study this filtering behaviour in more depth. In this work, investigation of this kind of tire response has been studied for agricultural tractor tire rolling quasistatically over singular road obstacle. Frequency analysis of road excitation and tyre response was carried out in order to obtain their spectra and frequency response function magnitude of the tyre as filter was obtained by dividing input by output spectra. Final assessment of frequency response function magnitude was obtained by averaging instances obtained for different dimensions of input obstacles.

  • Visual Analysis and Geometric Modeling of Metal Foams
    89-92
    Views:
    101

    The development of an efficient procedure for 3D modelling and finite element simulation of metal foams
    is one of the greatest challenges to engineer researchers nowadays. Creating 3D CAD model is alone a demanding
    engineering task due to its extremely complex geometry, and the proper finite element analysis process is still in the
    center of the research. The aim of this project is to analyze the related literature and to adapt the results may be
    considered.

  • Effect of the Flow Curve Determination on the Thinning of Drawn Parts
    16-25
    Views:
    73

    This study presents the results of finite element simulations based on different variations of the flow curve of DC04 automotive thin sheet. The aim of our research is to investigate how different flow curve equations affect the variation of sheet thickness in cup drawing tests. In order to exclude other influencing factors in the experiment, both the sheet material and the geometric properties of the specimen, as well as the external state factors were considered to be the same in all cases. The finite element simulations were performed using Simufact 2021.1 software. Our results shows that there are no significant differences in wall thicknesses until we reach the zone of double necking, where essential differences are observed.

  • The Effect of MMS Lubrication on Surface Roughness During Machining
    452-457
    Views:
    80

    I display this paper the chipping front metal of cutting allocated geometric, considering particular the friction. I catch the attention energy's balance sheet someday metal of cutting, open one new direction the manufacture technology. I display this new direction's metal of cutting condition. but built I delineate his paper final division this new policy searching programme, consumed trial instruments as well as the evaluation's mode.

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