Influence of cyclic frozen and defrost on mechanical properties of polytetrafluoroethylene (PTFE)-coated woven fabrics

This research aims to determine the influence of the cyclic process of freezing and defrosting on the mechanical properties of the chosen glass fibres and PTFE-coated woven fabrics. The specimens were subjected to freezing at about -20˚C for 4 h and thawing by full immersion into the water at about +20˚C for 4 h. The fabric samples after 25 and 50 frozen cycles were air-dried at room temperature for one week and then subjected to uniaxial tensile tests. The same tests have been performed on a reference group of specimens, which were not exposed to temperature change. The authors determined the tensile strength, and longitudinal stiffnesses resulting from performed tests. Although the investigated coated woven fabrics expressed a reduction in the tensile strength in water soaking conditions, the performed frozen cycles don’t show a significant decrease in strength under uniaxial tensile tests

PROJEKTOWANIE SYSTEMÓW ANALIZY DANYCH DO AUTOMATYZACJI PROCESÓW BIZNESOWYCH

The paper deals with the design of data analysis systems for business process automation. The main goal of the project is to develop an innovative system for analyzing multisource data, business data mining processes, and as a result the creation and sharing of new improved procedures and solutions.Artykuł dotyczy projektowania systemów analizy danych do automatyzacji procesów biznesowych. Głównym celem projektu jest opracowanie innowacyjnego systemu do analizy danych wieloźródłowych, procesów eksploracji danych biznesowych, a co za tym idzie tworzenie i udostępnianie nowych ulepszonych procedur i rozwiązań

KONCEPCJA PARAMETRYCZNO-SEMANTYCZNEJ OTWARTEJ PLATFORMY INTELIGENTNYCH URZĄDZEŃ SENSOROWYCH

The parametric and semantic model of open platform of intelligent devices and sensor technologies based on tomography in cyber-physical self-monitoring system contains: new techniques of conducting measurements and construction of novel intelligent measurement devices, system's structure along with communication interface, unique algorithms for data optimization and analysis, algorithms for image reconstruction and technological processes monitoring, cyber-physical system's prototype.Parametryczno-semantyczny model otwartej platformy inteligentnych urządzeń sensorowych został oparty na technologiach tomograficznych. W samo-monitorującym się systemie cyber-fizycznym zastosowano nowe techniki pomiarowe i konstrukcje inteligentnych urządzeń pomiarowych. Proponowane rozwiązanie prototypu systemu cyber-fizycznego składa się z interfejsu komunikacyjnego, unikalnych algorytmów do optymalizacji i analizy danych oraz systemu monitoringu procesów logistyczno-technologicznych

Wpływ wytrzymałości na rozciąganie tkanin powlekanych na bazie poliestru w warunkach moczenia w wodzie

This research aims to determine the influence of water-soaking on polyester-based coated woven fabrics for ultimate tensile strength and elongation at break under uniaxial tensile tests. The paper begins with a short survey of literature concerning the investigation of the determination of coated woven fabric properties. The authors carried out the uniaxial tensile tests with an application of a flat grip to establish the values of the ultimate tensile strength of groups of specimens treated with different moisture conditions. SEM fractography is performed to determine the cross-section structures of coated woven fabrics. The change in the mechanical properties caused by the influence of water immersion has not been noticed in the performed investigations.Niniejsze badania mają na celu określenie wpływu nasiąkania wodą na poliestrowe tkaniny powlekane na wytrzymałość na rozciąganie i wydłużenie przy zerwaniu w próbach jednoosiowego rozciągania. Artykuł rozpoczyna się od krótkiego przeglądu literatury dotyczącej badań nad właściwościami tkanin technicznych. Autorzy przeprowadzili próby rozciągania jednoosiowego z użyciem szczęk płaskich w celu wyznaczenia wartości wytrzymałości na rozciąganie grup próbek poddanych działaniu różnych warunków wilgotnościowych. Wykonano także fraktografie SEM w celu określenia struktury przekrojowej tkanin powlekanych. W przeprowadzonych badaniach nie zauważono zmiany właściwości mechanicznych pod wpływem zanurzenia w wodzie

Consideration of the safety of bungee jumping in relation to mechanical properties of the installation based on a jump accident in Gdynia

This paper considers a bungee jumping accident that took place in July 2019 in Gdynia, Poland. The authors conducted an investigation to determine the cause of the bungee rope failure. It was based on mechanical tests concerning the strength of the rope as well as the calculation of the force induced in the rope during the jump. Based on the theoretical and experimental results, the rope safety factor was estimated. It appeared to be three-fold lower than it is recommended in Polish regulations concerning ropes dedicated to lifting people for industrial and public purposes. However, no law regulations strictly concerning bungee installation makes it easy for accidents to occur

Influence of Water-Induced Degradation of Polytetrafluoroethylene (PTFE)-Coated Woven Fabrics Mechanical Properties

The impact of water-induced degradation on the mechanical properties of the chosen two PTFE-coated, glass threads woven fabrics is investigated in this paper. The paper begins with a survey of literature concerning the investigation and determination of coated woven fabric properties. The authors carried out the uniaxial tensile tests with an application of flat and curved grips to establish the proper values of the ultimate tensile strength and the longitudinal stiffness of groups of specimens treated with different moisture conditions. Despite the water resistance of the main materials used for fabrics manufacturing, the change of the mechanical properties caused by the influence of water immersion has been noticed. The reduction in the tensile strength resulting under waterlogged is observed in the range from 5% to 16% depending on the type of investigated coated woven fabric and direction of weft or warp

Testing of Technical Fabrics under Fast Camera Control

The dynamic development of measurement and recording techniques has been changing the way one conceives material strength. In this study, two different methods of evaluating the strength of fabrics are compared. The first is the typical and commonly used technique based on the use of a testing machine. The second method uses the so-called “fast camera” to monitor the entire process of the destruction of a fabric sample and analyse the behaviour of the fabric during the experiment. Both methods provide interesting data and present a very specific way of experimentally evaluating the strength of fabrics

Comparison of Selected Machine Learning Algorithms for Industrial Electrical Tomography

The main goal of this work was to compare the selected machine learning methods with the classic deterministic method in the industrial field of electrical impedance tomography. The research focused on the development and comparison of algorithms and models for the analysis and reconstruction of data using electrical tomography. The novelty was the use of original machine learning algorithms. Their characteristic feature is the use of many separately trained subsystems, each of which generates a single pixel of the output image. Artificial Neural Network (ANN), LARS and Elastic net methods were used to solve the inverse problem. These algorithms have been modified by a corresponding increase in equations (multiply) for electrical impedance tomography using the finite element method grid. The Gauss-Newton method was used as a reference to machine learning methods. The algorithms were trained using learning data obtained through computer simulation based on real models. The results of the experiments showed that in the considered cases the best quality of reconstructions was achieved by ANN. At the same time, ANN was the slowest in terms of both the training process and the speed of image generation. Other machine learning methods were comparable with the deterministic Gauss-Newton method and with each other

Validation of Hydraulic Mechanism during Blowout Trauma of Human Orbit Depending on the Method of Load Application

The more we know about mechanisms of the human orbital blowout type of trauma, the better we will be able to prevent them in the future. As long as the buckling mechanism’s veracity is not in doubt, the hydraulic mechanism is not based on equally strong premises. To investigate the correctness of the hydraulic mechanism’s theory, two different methods of implementation of the hydraulic load to the finite element method (FEM) model of the orbit were performed. The intraorbital hydraulic pressure was introduced as a face load applied directly to the orbit in the first variant, while in the second one the load was applied to the orbit indirectly as a set of nodal forces transferred from the external surface of the eyeball via the intraorbital tissues to the orbital walls within the contact problem. Such an approach is aimed at a better understanding of the pattern for the formation of blowout fractures during the indirect load applied to the orbital bones. The nonlinear dynamic analysis of both numerical models showed that the potential fracture was observed in the second variant only, embracing a relatively large area: both medial and lower wall of the orbit. Interestingly, the pressure generated by the intraorbital entities transferred the energy of the impact to the orbital sidewalls mainly; thus, the nature of the mechanism known as the hydraulic was far from the expected hydraulic pressure. According to the eyeball’s deformation as well as the areas of the greatest Huber-Mises-Hencky (H-M-H) stress within the orbit, a new term of strut mechanism was proposed instead of the hydraulic mechanism as more realistic regarding the investigated phenomenon. The results of the current research may strongly influence the development of modern implantology as well as affect forensic medicine