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Influence of a Directional Dependenceon Mechanical Properties of Composites Reinforced with Chopped Carbon Fibre Produced by Additive Manufacturing

Majko Jaroslav, Handrik Marian, Vaško Milan, Sága Milan, Kopas Peter, Dorčiak Filip, Sapietová Alžbeta

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

455--461

EN

Progress in the industry is accompanied by the development of new materials and more efficient technological production processes. At present, additive production is becoming very attractive in all industries (research, development, production), which brings a number of advantages compared to subtractive methods (customization, production speed, control of material properties by users, etc.). The main advantage of 3D printing is the controlled deposition of material in defined places. Instead of demanding manual labour, fully automated production via computers leads to the manufacturing of complex components from materials whose production in conventional ways would be problematic or even impossible. Because these are new technologies, the main direction of research at present is to identify the basic physical properties of these materials under different types of loading. The main goal of this article is to observe the dependence of the behaviour of the extruded material (thermoplastic reinforced with chopped carbon fibre) on the printing parameters (thickness of the lamina, the orientation of the fibres of the printed material, etc.). Based on published scientific works, it appears that these settings have a significant impact on the achieved physical properties. This is the reason why the authors decided to analyze the influence of these parameters on the basis of processed data from experimental measurements of mechanical properties in the MATLAB program. As this is FFF printing, an essential condition is to identify and specify the directional dependence of the behavior of the printed material. This physical phenomenon is a necessary condition for gradual knowledge for the purposes of a subsequent mathematical description of the material properties. According to the authors, for the purposes of modeling these materials in FEM-based programs, it is essential to define the directional dependence in the plane of the lamina.

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Acoustic Emission and Infrared Thermography Study of Low Strain Tensile Behaviour of AISI 304L Stainless Steel

Sapietová Alžbeta, Raček Marek, Dekýš Vladimir, Sapieta Milan, Sága Milan, Šofer Pavel

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

463--468

EN

In-situ study of deformation behaviour and mechanisms occurring during early stages of deformation is of a great practical importance. Low stacking fault energy materials, as is the case of AISI 304L, show non-linear deformation characteristics way below the bulk yield point. Shockley partial dislocations, formation of stacking faults respectively, resulting in creation of shear bands and ε-martensite transformation are the mechanisms occurring in the low strains in the studied steel. Acoustic emission and infrared thermography have been used in this study to investigate the deformation kinetics at the low strain stages of slow strain rate tensile tests. Acoustic emission cumulative energy together with the tracking of specimen maximum temperature have been found to be very useful in-situ techniques both supplementing each other in the sense of the sensitivity to different mechanisms. Mechanical, acoustic emission and infrared thermography results are discussed in detail with respect to potential occurred mechanism.

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Vibrodiagnostics of rolling ball bearings connected with processing, result´s comparison and prediction of service life

Šulka Peter, Sapietová Alžbeta, Bárnik František

Zeszyty Naukowe. Transport / Politechnika Śląska

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2020

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z. 106

183--196

EN

This article deals with vibration analysis and the processing of the vibration signal obtained during the experimental measurement on a rotary shaft at start-up, constant speed and run-out, with rolling ball bearings. The next step of the research is the introduction and application of mathematical and numerical methods for the processing of input and measured data using diagnostic and mathematical software. The principle of measurement and processing was to compare the results of oscillation of an undamaged bearing with several types of damaged bearings with corresponding deformations in the orbits/raceways. The purpose of this research and comparison was to achieve optimal results (in terms of amplitude values, the occurrence of eigenvalue vibrations and the resonance phenomenon) of individual bearings with corresponding deformations in the raceways and to obtain calibration diagrams as a tool for possible prediction of bearings in operation.

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Realization and Verification of Data Conversion from Laser Scanner to FEM

Sapietová Alžbeta, Štalmach Ondrej, Sága Milan, Stančeková Dana, Gajdoš Lukáš

Advances in Science and Technology. Research Journal

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2020

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Vol. 14, no 1

69--74

EN

This paper deals with the data processing in the form of a point cloud scanned using a handheld 3D laser scanner. The aim of the paper was to use this data to create a representative FEM model and compare two different ap¬proaches, one them involved creating a CAD model and the other one did not. The data processing was carried out in the freeware systems MeshLab and Meshmixer and FEM analysis in the software ANSYS Workbench.

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Dynamic and Stress Analysis of a Locking Mechanism in the Ansys Workbench Software Environment

Sapietová Alžbeta, Novák Pavol, Sága Milan, Šulka Peter, Sapieta Milan

Advances in Science and Technology. Research Journal

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2019

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Vol. 13, no 1

23--28

EN

This paper presents dynamic and stress analysis of a virtual prototype (VP) of a lock mechanism, which would lead to verification of its functionality in terms of kinematic, dynamic and strength parameters. The proposed modifications of input parameters of the technical equipment addressed were verified using the software environment of MSC. ADAMS and FEM software ANSYS Workbench.