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Search results for: AXLE LOAD SPECTRA, DYNAMIC LOADS, INTERNATIONAL ROUGH INDEX, DYNAMIC LOAD COEFFICIENT, LOAD EQUIVALENCY FACTOR.
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The use of Response Surface Methodology for reliability estimation of aluminum silo subjected to wind load
PublicationAn axisymmetric aluminum silo model with a single, standardized geometric imperfection of its lateral surface is considered. The silo is wind – loaded only. The paper is focused on the critical, or limit value of wind pressure, both producing a loss of stability of the silo. This value is affected by vertical coordinate (position) of the imperfection and the angular relation between the imperfection and the wind direction. Reliability...
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Voltage and Reactive Power Load Flow Optimization in the Power System Using Fuzzy Logic
PublicationThe paper presents issues related to voltage control in the power system. An original method of reactive power flow optimization is considered, which leads to improved voltages in the power system and reduced active power losses. The optimization method is based on a procedure that employs fuzzy logic and is supported by a gradient search algorithm. The method has been implemented in PLANS software and verified.
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The influence of height-to-diameter ratio on wind load of double-shell cylindrical, vertical tank
PublicationW pracy zaprezentowano badania modelowe obciążenia wiatrem dwupłaszczowych zbiorników walcowych o różnych smukłościach aerodynamicznych. Przedstawiono wyniki pomiarów przeprowadzonych na dwóch modelach zbiorników z dachem pływajacym i stosunku wysokości do średnicy płaszcza 0,45 i 0,25.
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Application of speed and load torque observers in high-speed train drive for diagnostic purposes
PublicationW artykule przedstawiono zastosowanie diagnostyczne obserwatorów prędkości obrotowej i momentu obciążenia w układzie napędowym z silnikiem asynchronicznym. System diagnostyczny jest dedykowany do napędu pociągu szybkiego. Celem diagnostycznym jest monitorowanie stanu czujnika prędkości obrotowej wału silnika oraz układu przeniesienia momentu trakcyjnego. Analiza sygnałów obliczanych w obserwatorach stanu pozwala na wykrycie uszkodzeń...
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The laboratory experiments on reduction of organic pollutants load in was-tewater generated in fish processing industry
PublicationPrzeprowadzono próby obniżenia ładunku zanieczyszczeń w ściekach z przemysłu rybnego przed ich odprowadzeniem do sieci kanalizacji miejskiej. Wykorzystano koagulację do wydzielenia ze ścieków białek i tłuszczów. Uzyskany osad pokoagulacyjny dodawano do produkcji rybnych hydrolizatów białkowych. Zmodyfikowano metodę wytwarzania hydrolizatów poprzez zamianę kwasu siarkowego na fosforowy. Dzięki tej zmianie obniżono zawartość żelaza...
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Sources of contamination in sediments of retention tanks and the influence of precipitation type on the size of pollution load
PublicationDensification of cities and urban population contributes to increased runoff and suspended solids and alteration of the urban water cycle. Nowadays, Blue-Green Infrastructure is promoted to increase a city’s resilience to floods; however, stormwater drainage systems, supported with retention tanks are still important in protecting urban areas against floods. Sediment accumulation in stormwater infrastructure relates to an issue...
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Mechanics of mesh implanted into abdominal wall under repetitive load. Experimental and numerical study
PublicationThere are a number of papers discussing medical and mechanical aspects of ventral hernia management. Despite intensive work on the problem understanding, recurrences of the sickness still happen too often. For that reason new aspects of the problem must be considered. In this paper, a change in the abdominal implant’s stiffness is discussed, which is caused by cyclic loading. Such loading influence abdominal implant e.g. while...
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Dynamic charging of electric buses
PublicationDespite the continuous development of electrochemical battery technology and the multitude of electric buses on offer, it is still not possible to exploit electric buses in urban transport on an all-day basis without the necessity of charging them. It is therefore necessary to build point-to-point contact charging stations or induction charging stations at the terminals. This results in substantial financial outlays connected with...
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Experimental dynamic study on a timber-frame house using shaking table
PublicationThe aim of this paper is to show the results of the shaking table experimental study concerning the behaviour of the model of the timber-frame house under earthquake excitation and impact loading. In order to determine the basic dynamic properties of the undamaged structure, the free vibration and the sweep-sine tests were first conducted. Then, the model was excited using the time history record of the El Centro earthquake of...
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Solving the Problem of Dynamic Adaptability of Artificial Intelligence Systems that Control Dynamic Technical Objects
PublicationThis paper investigates the increase in the response speed and stability of artificial intelligence systems that control dynamic technical objects. The problem of calculating the optimal time of switching an artificial intelligence system between software classes by the criterion of the rigidity degree of the model of a control object is considered. The solution of this problem is proposed for the general case of the control object...
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A Surveillance Of Dynamic Processes in Selected Mechatronic Systems
PublicationThe paper concerns development of original method of optimal control at energy performance index and its application to dynamic processes surveillance of some mechatronic systems. The latter concerns chatter vibration surveillance during highspeed slender milling of rigid details, as well as motion control of two-wheeled mobile platform. Results of on-line computer simulations and real performance on the target objects reflect...
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The impact of air humidity on the operation of proton exchange membrane fuel cells determined using dynamic electrochemical impedance spectroscopy
PublicationThis paper describes the changes in the fuel cell impedance across a range of current loads and humidity changes. The changes of each equivalent circuit parameters representing specific processes occurring in fuel cells, as a function of humidity and current changes, were determined. Within the combined scope of current and humidity, the optimal working conditions of the cells were determined, corresponding to the lowest impedance...
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Fractographic-fractal dimension correlation with crack initiation and fatigue life for notched aluminium alloys under bending load
PublicationIn this study, fatigue fracture surfaces of aluminium alloy 2017-T4 notched specimens were investigated under cyclic bending to find an alternative failure loading index.. The surface topographies were measured on the entire fracture area with an optical profilometer for different loading conditions. Fatigue crack initiation life Ni and total fatigue life Nf were examined using standard surface topography parameters (such as, root...
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The consideration to the dynamic systems parameter identification
PublicationIn this paper, a concept for continuous-time dynamic systems parameter identification using modulating function approach is presented. It refers to linear as well as selected non-linear systems. It shows the possibility of direct application without converting differential equation. In particular cases direct application can decrease the amount of computation in non-linear system identification, which generally requires Fourier...
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Dynamic mass measurement in checkweighers using a discrete time-variant low-pass filter
PublicationConveyor belt type checkweighers are complex mechanical systems consisting of a weighing sensor (strain gauge load cell, electrodynamically compensated load cell), packages (of different shapes, made of different materials) and a transport system (motors, gears, rollers). Disturbances generated by the vibrating parts of such a system are reflected in the signal power spectra in a form of strong spectral peaks, located usually in...
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Analysis od dynamic loads on lightweight footbridge caused by lorry passing underneath
PublicationW artykule przedstawiono analizę drgań lekkiej kładki dla pieszych wywołanych przejazdem ciężarówki z dużą prędkością pod spodem konstrukcji.
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Dynamic analysis of the impact of the wind spectrum according to the theory of Davenport for lightweight structures of the roof in sports hall Czyzyna in Cracow.
PublicationThe main aim of this analysis is to characterize numerical simulations connected with modeling dynamic influence of wind on the lightweight structures of the roof in sports hall – “Czyżyna”. This hall is built in Cracow. The article also involves the proposals of the solutions connected with dynamic influence of the wind – Davenport’s method has been used. These proposals have not been taken into consideration at the detailed engineering...
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Static and dynamic concrete calculations: Breakable aggregates in DEM model
PublicationThe paper deals with the calculations of a 3-point bending beam under static and dynamic loads. The real microstructure was obtained from laboratory tests using micro-tomography images. The quasi-static results were compared directly with experimental data at both macro and micro levels. Subsequently, higher strain rates were applied to investigate dynamic effects. The study focused on the influence of dynamic loading on the macroscopic...
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Dynamics of the small-span railway bridge under moving loads
PublicationThe paper presents the results of dynamic analysis of the small-span railway bridge, subjected to an action of moving trains. Numerical simulations were performed using three different load models: series of moving forces, series of moving single-mass and double-mass oscillators. The parameters of the vehicle were taken from the existing EN57 train. The parameters of the bridge were taken from the existing steel span of 10,24 m...
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Experimental study on static and dynamic properties of polymer mass
PublicationA new method of repairing damaged structures by filling the cracks with a specially prepared polymer mass has been recently proposed. This new and innovative technique, known as the Flexible Joint Method (FJM), is mainly dedicated to masonries and historical objects, where minimum intervention is permitted. The flexible joint bonds the disrupted elements and ensures further safe exploitation of a damaged structure. The aim of the...
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Susceptibility of the LLC Resonance Generator for Induction Heating on Changes in Load Parameters Caused by Heating the Charge
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Pelvic vertical shear fractures: The damping properties of ligaments depending on the velocity of vertical impact load
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The influence of height-do-diameter ratio on wind load of double-shell cylindrical, vertical tank
PublicationW pracy zaprezentowano skrót badań modelowych obciążenia wiatrem dwupłaszczowych zbiorników walcowych o różnych smukłościach aerodynamicznych. Przedstawiono wyniki pomiarów przeprowadzonych na dwóch modelach zbiorników z dachem pływającym i stosunku wysokości do średnicy płaszcza 0,45 i 0,25.
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Wind tunnel experiments and numerical analysis of the wind load on double-shell cylindrical, vertical tanks
PublicationW pracy przedstawiono wyniki badań modelowych w tunelu aerodynamicznym oraz symulacji komputerowych obciążenia wiatrem pionowych, walcowych zbiorników dwupłaszczowych z dachem pływającym. W badaniach modelowych analizowano wpływ rozstawu między płaszczami zbiornika na wartość i rozkład współczynnika ciśnienia na płaszczach oraz dachu pływającym. Wyniki symulacji komputerowych przeprowadzonych w programie Fluent porównano z wynikami...
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Problem of optimal load distribution between generators minimizing risk of enegretic ship system overload.
PublicationOmówiono system rozdziału mocy czynnych pomiędzy generatorami w systemie energetycznym statku. Minimalizuje się ryzyko przeciążeń systemu przy jednoczesnej minimalizacji kosztów wytwarzania energii w systemie.
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Dynamic Content Internationalization in Web Applications
PublicationThis paper shows a concept for providing dynamic internationalization to web applications. Presented work is based on the Java Web Platform but described concepts can be successfully implemented on other platforms. It shows how textual data being part of web pages static and dynamic content can be localized dynamically during application runtime. All concepts presented were or are still being developed in an existing conference...
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Dynamic ranking of cloud providers
PublicationThe paper focuses on how to create an effective dynamic ranking service for IaaS,PaaS and SaaS cloud providers. It considers building of a quality model for thispurpose along with definition of quality measurement procedures. The paper discussesseveral techniques known from already existing price comparison engines that couldbe modified and adopted for comparison of cloud providers. Furthermore, a tech-nique for filtering measured...
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Research on the effect of low-sulphur marine fuels on the dynamic characteristics of a CI engine
PublicationThe implementation of low-sulphur, so-called modified marine fuels into operation requires prior labora- tory engine tests to assess the energy, emission and structural effects of their usage. This type of research are carried out on the test bed of a diesel engine as a small-scale physical model that reproduces the adequate design and process (parametric) features of a full-size marine engine. Their key stage is to determine the energy...
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Enhancement of Countermovement Jump Performance Using a Heavy Load with Velocity-Loss Repetition Control in Female Volleyball Players
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Finite element modeling of plastic hinges based on ductility demand-capacity method using nonlinear material for dynamic analysis
PublicationThe article discusses modeling plastic hinges in reinforced concrete interme-diate supports using finite elements methods. The ductility demand-capacitymethod was used to determine the geometrical parameters of cross-section plas-ticization zones, their ability to move and rotate, as well as their ductility. Dueto the varied geometry and stiffness of the supports and their nonlinear behav-ior under dynamic load, this method was...
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POSSIBILITY OF ASSESSMENT OF OPERATION OF SLIDING BEARINGS IN PISTON-CRANK MECHANISMS OF DIESEL ENGINES WITH REGARD TO LOAD AND TIME OF CORRECT WORK OF THE BEARINGS BY APPLYING ACOUSTIC EMISSION AS A DIAGNOSTIC SIGNAL
PublicationAbstract: The paper presents a possibility of determining (assessing) operation of sliding bearings with multilayer bushings in crank-piston mechanisms of diesel engines. Properties of load and wear, particularly fatigue and abrasive, are characterized in general. Acoustic emission as a diagnostic signal was proved to be useful for detection of the wear of sliding and barrier layers. Results of measurements of acoustic emission...
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Boundary value problems for dynamic equations with advanced arguments on time scales
PublicationPraca dotyczy równań i nierówności dynamicznych z wyprzedzonym argumentami. Przedmiotem badań były problemy istnienia rozwiązań równań dynamicznych. Sformułowano warunki dostatczne na istnienie jedynego rozwiązania w odpowiednim obszarze ograniczonym przez górne i dolne rozwiązanie.
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Dynamic Semantic Visual Information Management
PublicationDominant Internet search engines use keywords and therefore are not suited for exploration of new domains of knowledge, when the user does not know specific vocabulary. Browsing through articles in a large encyclopedia, each presenting a small fragment of knowledge, it is hard to map the whole domain, see relevant concepts and their relations. In Wikipedia for example some highly relevant articles are not linked with each other....
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Selected Features of Dynamic Voting
PublicationIn multi-agent systems composed of autonomous agents with local knowledge, it is often desirable to aggregate their knowledge in order to make an educated decision. One of the methods of agreeing to a common decision is voting. A new history-based dynamic weight protocol allows for identification of the agents which contribute to the correct system decision. The main advantage of this approach, compared to static weighted system...
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The Development of a Combined Method to Quickly Assess Ship Speed and Fuel Consumption at Different Powertrain Load and Sea Conditions
PublicationDecision support systems (DSS) recently have been increasingly in use during ships operation. They require realistic input data regarding different aspects of navigation. To address the optimal weather routing of a ship, which is one of the most promising field of DSS application, it is necessary to accurately predict an actually attainable speed of a ship and corresponding fuel consumption at given loading conditions and predicted...
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Adaptive dynamic control allocation for dynamic positioning of marine vessel based on backstepping method and sequential quadratic programming
PublicationIt is generally assumed in dynamic positioning of over-actuated marine vessels that the control effectiveness matrix (input matrix) is known and constant, or, in case of fault information, it is estimated by the fault detection and diagnosis system. The purpose of the study is to develop the adaptive dynamic positioning control system for an over-actuated marine vessel in the presence of uncertainties and with emphasis on limited...
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SPECTRAL DYNAMIC ANALYSIS OF A STATIONARY JACK-UP PLATFORM
PublicationThe paper refers to the dynamic short-term response analysis of the Baltic steel drilling platform (see Fig.2) in a random sea-state represented by one-dimensional wave spectrum proposed by Striekalov and Massel and it is recommended for the Baltic Sea area. The Baltic drilling platform is a jack-up type platform for the exploration and exploitation of oil under the Baltic Sea. The analysis presented deals with the stationary...
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Speed Sensorless AC Drive with Inverter LC Filter and Fault Detection Using Load Torque Signal
PublicationThe industrial development in recent years has seen a major increase in the use of induction motors, whereby the cost has to be as low as possible and the lifetime as long as possible. To follow up this desire, investigations in this area have become very intense. For that reason, this paper presents a solution for driving an induction motor and simultaneous fault detection with no need for additional sensors. In order to achieve...
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Analysis of load carrying capacity and destruction mechanism of an intermediate anchorage steel plate for pillar jib crane
PublicationPillar jib cranes are often mounted to existing floors with the use of an intermediate anchorage steel plate instead of using independent foundations, what is shown in the figure. Standards for steel design provide only basic rules for the design of such an intermediate plate. This study presents a simple design approach by using a numerical model in order to analyze different parameters that have significant influence in the anchorage...
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Arterial stiffness increases in response to an acute arterial load challenge induced by an isometric handgrip in healthy individuals
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Influence of energy absorbers on Malgaigne fracture mechanism in lumbar-pelvic system under vertical impact load
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Bearing capacity of piles based on static load tests and calculation principles provided by EN 1997-1
PublicationW artykule scharakteryzowano i przeanalizowano ogólne zalecenia Eurokodu 7 dotyczące wyznaczania nośności pali na podstawie próbnych obciążeń statycznych. Porównano je z zaleceniami dotychczasowej polskiej normy PN-83/B-02482. Przedstawiono kilka przykładów interpretacji rzeczywistych wyników próbnych obciążeń pali według zaleceń wyżej wymienionych dwóch norm wraz z analizą porównawczą.
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Differential Quadrature Method for Dynamic Buckling of Graphene Sheet Coupled by a Viscoelastic Medium Using Neperian Frequency Based on Nonlocal Elasticity Theory
PublicationIn the present study, the dynamic buckling of the graphene sheet coupled by a viscoelastic matrix was studied. In light of the simplicity of Eringen's non-local continuum theory to considering the nanoscale influences, this theory was employed. Equations of motion and boundary conditions were obtained using Mindlin plate theory by taking nonlinear strains of von Kármán and Hamilton's principle into account. On the other hand, a...
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CREATING A RANKING OF DIAGNOSTIC PARAMETERS FOR THE DYNAMIC PROCESS OF A MARINE COMBUSTION ENGINE IN THE ASPECT OF MULTI-CRITERIA EVALUATIONS
PublicationThe change of some of the engine’s structural parameters affects the change of toxic compound emission in exhaust gases. It mainly applies to the damage sustained by the charge exchange system as well as the fuel system and the engine supercharging system. These changes are definitely higher during dynamic states and the related transient states. As such, it is possible to speak of a diverse sensitivity of the diagnostic parameters...
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Dynamic Properties of Two-Axle Freight Wagon with UIC Double-Link Suspension as a Non-smooth System with Dry Friction
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Fractional Order Dynamic Positioning Controller
PublicationImproving the performance of Dynamic Positioning System in such applications as station keeping, position mooring and slow speed references tracking requires improving the position and heading control precision. These goals can be achieved through the improvement of the ship control system. Fractional-order calculus is a very useful tool which extends classical, integer-order calculus and is used in contemporary modeling and control...
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A LABORATORY STAND FOR THE ANALYSIS OF DYNAMIC PROPERTIES OF THERMOCOUPLES
PublicationIn the present elaboration, problems connected with measurements of high variable temperatures of gases are introduced and the impact of dynamic properties of different construction solutions of thermoelements on the accuracy of the measurements is considered. A laboratory stand built within research under doctoral thesis, destined for analysis of dynamic properties of thermocouples is also described. Results of numerical simulation...
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GENERAL DYNAMIC PROJECTING OF MAXWELL EQUATIONS
PublicationA complete – system of Maxwell equations is splitting into independent subsystems by means of a special dynamic projecting technique. The technique relies upon a direct link between field components that determine correspondent subspaces. The explicit form of links and corresponding subspace evolution equations are obtained in conditions of certain symmetry, it is illustrated by examples of spherical and quasi-one-dimensional waves.
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Novel analysis methods of dynamic properties for vehicle pantographs
PublicationTransmission of electrical energy from a catenary system to traction units must be safe and reliable especially for high speed trains. Modern pantographs have to meet these requirements. Pantographs are subjected to several forces acting on their structural elements. These forces come from pantograph drive, inertia forces, aerodynamic effects, vibration of traction units etc. Modern approach to static and dynamic analysis should...
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Simple Computational Methods in Predicting Limit Load of High-Strength Cold-Formed Sections due to Local Buckling: A Case Study
PublicationCold-formed thin-walled sections are prone to local buckling caused by residual stresses, geometrical imperfections and inconsistency of material properties. We present a real case of buckling failure and conduct a numerical and experimental study aimed to identify methods capable of predicting such failures. It is important because designers of structures are getting more FEA-oriented and tend to avoid lengthy procedures of cold-formed...