Filtry
wszystkich: 1754
-
Katalog
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: FINTE ELEMENT METHOD MECHATRONIC SYSTEMS
-
Diagonalized Macromodels in Finite Element Method for Fast Electromagnetic Analysis of Waveguide Components
PublikacjaA new technique of local model-order reduction (MOR) in 3-D finite element method (FEM) for frequency-domain electromagnetic analysis of waveguide components is proposed in this paper. It resolves the problem of increasing solution time of the reduced-order system assembled from macromodels created in the subdomains, into which an analyzed structure is partitioned. This problem becomes particularly relevant for growing size and...
-
SSFR Test of Synchronous Machine for Different Saturation Levels using Finite-Element Method
PublikacjaIn this paper the StandStill Frequency Response characteristics (SSFR) of saturated synchronous generator (SG) have been calculated using Finite Element Method (FEM) analysis. In order to validate proposed approach for unsaturated conditions FEM simulation from Flux2D software has been compared with the measurements performed on the 10 kVA, 4- poles synchronous machine ELMOR GCe64a of salient rotor construction, equipped with a...
-
Analysis of ring cracks in ceramic rolling elements using the boundary element method
PublikacjaCeramic materials have been increasingly used in bearing technology for over a dozen years. This is due to the characteristic properties of ceramic materials such as: high hardness, corrosion resistance, the possibility of use in aggressive chemical environments, as well as due to the lower specific weight compared to steel materials. However, the use of ceramic materials is connected with many limitations. The main disadvantages...
-
An Enhanced Reduced Basis Method for Wideband Finite Element Method Simulations
PublikacjaIn this paper, we present a novel strategy for selecting expansion points in the reduced basis method. A single computation of the error estimator is used to select a few expansion points in the multi-parameter space simultaneously. The number of selected points is determined adaptively, based on the accuracy of the current reduced model. The reliability and efficiency of this proposed approach are illustrated by numerical tests...
-
Application of the numerical-analytic method for systems of differential equations with parameter
PublikacjaThe numerical-analytic method is applied to systems of differential equations with parameter under the assumption that the corresponding functions satisfy the Lipschitz conditions in matrix notation. We also obtain several existence results for problems with deviations of an argument
-
Processing of point cloud data retrieved from terrestrial laser scanning for structural modeling by Finite Element Method
PublikacjaFinite Element Method is one most popular contemporary method of strength analysis. The method is an advanced method for solving differential equations, based on discretization, which means that area is divided into finite elements. Each finite element has a solution of the equation approximated by specific functions and performing the actual calculations only for nodes of this division. Finite Element Method is widely used in...
-
Study of the Effectiveness of Model Order Reduction Algorithms in the Finite Element Method Analysis of Multi-port Microwave Structures
PublikacjaThe purpose of this paper is to investigate the effectiveness of model order reduction algorithms in finite element method analysis of multi-port microwave structures. Consideration is given to state of the art algorithms, i.e. compact reduced-basis method (CRBM), second-order Arnoldi method for passive-order reduction (SAPOR), reduced-basis methods (RBM) and subspace-splitting moment-matching MOR (SSMM-MOR)
-
Discrete element method modelling of elastic wave propagation in a meso-scale model of concrete
PublikacjaThis paper deals with the accurate modelling of ultrasonic wave propagation in concrete at the mesoscopic level. This was achieved through the development of a discrete element method (DEM) model capable of simulating elastic wave signals comparable to those measured experimentally. The main objective of the work was to propose a novel methodology for constructing a meso-scale model of concrete dedicated to the analysis of elastic...
-
Mathematical Models of Control Systems of Angular Speed of Steam Turbines for Diagnostic Tests of Automatic and Mechatronic Devices
PublikacjaAccurate modeling of physical processes of many automatics and mechatronics systems is often necessity. In power system such a process is control of angular velocity of power objects during connection to operation in parallel. This process is extremely dynamic. For this reason response of control system depends from changes of many physical parameters (temperature, pressure and flow of the medium, etc.). Precision modeling influences...
-
Viscoplastic constitutive laws and their implementation it the finite element method
PublikacjaW pracy przedstawiono zasady formułowania i zastosowania w metodzie elementów skończonych lepkoplastycznych praw konstytutywnych. Podano skrótowo sposób identyfikacji parametrów i omówiono pewne szczególne założenia, które muszą być przyjęte aby można było dane prawo zastosować w obliczeniach numerycznych.
-
Damage detection of structures using spectral element method.
PublikacjaW pracy przedstawion mozlwiości detekcji uszkodzeń w postaci pęknięć zmęczeniowych i delaminacji z wykorzystaniem modeli budowanych za pomocą metody spektralnych elementów skończonych.
-
Modelling of concrete using lattice and discrete element method
PublikacjaModelowanie betonu przy zastosowaniu metody siatkowej i metody elementów dyskretnych.
-
A Method of Object Re-identiciation Applicable to Multicamera Surveillance Systems
PublikacjaThe paper addresses some challenges pertaining to the methods for tracking of objects in multi-camera systems. The tracking methods related to a single Field of Vision (FOV) are quite different from inter-camera tracking, especially in case of non-overlapping FOVs. In this case, the processing is directed to determine the probability of a particular object’s identity seen in a pair of cameras in the presence of places non-observed...
-
INTEGRATED FUNCTIONAL SAFETY AND CYBERSECURITY ANALYSIS METHOD FOR SMART MANUFACTURING SYSTEMS
PublikacjaThis article addresses integrated functional safety and cybersecurity analysis with regard to: the generic functional safety standard IEC 61508 and the cyber security standard IEC 62443 concerning an industrial automation and control system (IACS). The objective is to mitigate the vulnerability of information technology (IT) and operational technology (OT) systems, and reduce relevant risks taking into account a set of fundamental...
-
Adaptive Method of Raster Images Compression and Examples of Its Applications in the Transport Telematic Systems
PublikacjaThe paper presents a concept and exemplary application of an adaptive method of compression of raster images which may be applied, i.a. in ITS systems. The described method allows to improve the efficiency of systems belonging to ITS category, which require transmission of large volumes of image data through telecommunications networks. The concept of the adaptive method of compression of raster images described in the paper uses...
-
A study on microcrack monitoring in concrete: discrete element method simulations of acoustic emission for non-destructive diagnostics
PublikacjaThe research is focused on the monitoring of fracture evolution in concrete beams under three-point bending using the acoustic emission technique and the discrete element method. The main objective of the study was to numerically and experimentally investigate the mechanism behind the generation of elastic waves during acoustic emission events and their interaction with micro- and macro-cracking in concrete beams under monotonic...
-
Characterization of the c-BN/TiC, Ti3SiC2 systems by element selectivespectroscopy.
PublikacjaPomimo dużego technologicznego zainteresowania tytanowymi kompozytami bazującymi na c-BN daje się zauważyć wyraźny brak danych dotyczących lokalnego otoczenia atomów Ti w tego typu materiałach. Główna przyczyna tego stanu rzeczy tkwi w trudności związanej z analizą układu wielofazowego o dużej twardości za pomocą konwencjonalnych metod. Praca poświęcona jest analizie składu i struktury tytanowych kompozytów za pomocą atomowo-selektywnych...
-
DiSTFAG method robust to gross errors in monitoring displacements and strains in unstable reference systems
PublikacjaThe DiSTFA method (Displacements and Strains using Transformation and Free Adjustment) was presented in Kamiński (2009). The method has been developed for the determination of displacements and strains of engineering objects in unstable reference systems, as well as for examining the stability of reference points. The DiSTFAG (Gross errors) method presented in the paper is the extension of the DiSTFA method making it robust to...
-
Finite element modeling of plastic hinges based on ductility demand-capacity method using nonlinear material for dynamic analysis
PublikacjaThe 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...
-
The dynamic analysis of a cracked Timoshenko beam by the spectral element method
Publikacja -
Spectral Finite Element Method in Condition Monitoring and Damage Detection
PublikacjaIt is well known that the dynamic behaviour of engineering structures may carry very important and crucial information that can be further used for the assessment of their condition as well as detection of any damage induced. The current interest in monitoring techniques based on the propagation of guided elastic waves requires that numerical techniques used for modelling the phenomena associated must shift into the realm of high...
-
The dynamic analysisi of cracked Thimoshenko beam by the spectral element method.
PublikacjaW pracy przedstawiono model belli Timoshenko z pęknięciem poprzecznym oparty o metodę elementów spektralnych. Przedstawiono wyniki propagacji fali sprężystej i jej interakcję z pęknięciem.
-
adaptive finite-element multigrid method in 3d magnetostatic analysis.
PublikacjaPrzedstawiono procedurę analizy magnetostatycznej obwodów mikrofalowych zawierających przewodniki o dowolnym kształcie. Zakłada się pobudzenie pola magnetostatycznego zadane w postaci wartości całkowitego prądu płynącego w przewodniku sygnałowym. Warunki brzegowe w strukturze od dowolnym kształcie, bez płaszczyzn symetrii wprowadza się za pomocą powierzchni rozdzielających. Takie sformułowanie problemu prowadzi jednak do szeregu...
-
Studies of the Interaction Dynamics in Albumin-Chondroitin Sulfate Systems by Recurrence Method
PublikacjaThe physicochemical basis of lubrication of articular cartilage is still not fully understood. However, the synergy between components of the synovial fluid can be a crucial factor that could explain this phenomenon. This work presents a nonlinear data analysis technique named the recurrence method, applied to the system involving two components of synovial fluid: albumin and chondroitin sulfate (CS) immersed in a water environment....
-
Investigations of size effect in concrete at aggregate level - experiments and calculations results using discrete element method
PublikacjaSize effect is a fundamental phenomenon in concrete. It is characterised by decreasing strength and increasing brittleness of concrete with increasing size. The thesis includes experimental and theoretical elements. The main goal of the thesis were investigations of a size effect at the aggregate level by taking fracture into account with the discrete element method (DEM) for various failure modes. Comprehensive experiments on...
-
Preconditioners with Low Memory Requirements for Higher-Order Finite-Element Method Applied to Solving Maxwell’s Equations on Multicore CPUs and GPUs
PublikacjaThis paper discusses two fast implementations of the conjugate gradient iterative method using a hierarchical multilevel preconditioner to solve the complex-valued, sparse systems obtained using the higher order finite-element method applied to the solution of the time-harmonic Maxwell equations. In the first implementation, denoted PCG-V, a classical V-cycle is applied and the system of equations on the lowest level is solved...
-
A comparison method for ordinary differential systems
PublikacjaPraca dotyczy problemów istnienia i jednoznaczności rozwiązań oraz ciągłej zależności dla układów równań różniczkowych w tym i z opóźnionymi argumentami z warunkami początkowymi oraz brzegowymi typu okresowego. Przy odpowiednich założeniach, stosując teorię nierówności różniczkowych, pokazano, że odpowiednia funkcja porównawcza może być ujemna, co ma istotne znaczenie w dalszych badaniach. Pokazano, że konstruowany ciąg iteracji...
-
A method of self-testing of an analog circuit terminated by an ADC in electronic embedded systems controlled by microcontrollers
PublikacjaA new self-testing method of analog parts terminated by an ADC in electronic embedded systems controlled by microcontrollers is presented. It is based on a new fault diagnosis method based on on-line (i.e. during measurement), transformations of voltage samples of the time response of a tested part to a square pulse - onto localization curves placed in the measurement space. The method can be used for fault detection and single...
-
A new method of fault loop resistance measurement in low voltage systems with residual current devices
PublikacjaThis paper presents a new method of fault loop resistance measurement in low voltage systems with residual current devices. The method enables measuring fault loop resistance without nuisance tripping of residual current devices, by application an unconventional waveform of measurement current. It is important for proper verification of the effectiveness of protection against electric shock.
-
Decision-Making Models of the Human-Operator as an Element of the Socio-Technical Systems
PublikacjaThe authors of the chapter proved that the fundamental intellectual processes, which lie on the basis of decision-making behavior of the human-operator, could be identified on the bases on the analogies with the devices (elements). The basic intellectual processes of the Rational decision-making models can be adequately identified by the transient processes of the PID-controller; the intellectual processes of the Bounded Rationality...
-
High frequency dynamics of an isotropic Timoshenko periodic beam by the use of the Time-domain Spectral Finite Element Method
PublikacjaIn this work results of numerical simulations and experimental measurements related to the high frequency dynamics of an aluminium Timoshenko periodic beam are presented. It was assumed by the authors that the source of beam structural periodicity comes from periodical alterations to its geometry due to the presence of appropriately arranged drill-holes. As a consequence of these alterations dynamic characteristics of the beam...
-
Discrete element method simulations of fracture in concrete under uniaxial compression based on its real internal structure
PublikacjaThe paper describes experimental and numerical results of concrete fracture under quasi-static uniaxial compression. Experimental uniaxial compression tests were performed on concrete cubic specimens. Fracture in concrete was detected at the aggregate level by means of three non-destructive methods: three-dimensional X-ray microcomputed tomography, two-dimensional scanning electron microscope and manual two-dimensional digital...
-
A testing method of analog parts of mixed-signal electronic systems equipped with the IEEE1149.1 test bus
PublikacjaA new solution of the JTAG BIST for testing analog circuits in mixed-signal electronic microsystems controlled by microcontrollers and equipped with the IEEE1149.1 bus is presented. It is based on a new fault diagnosis method in which an analog circuit is stimulated by a buffered signal from the TMS line, and the time response of the circuit to this signal is sampled by the ADC equipped with the JTAG. The method can be used for...
-
Analysis of the Impact Resistance of Toecaps by the Finite Element Method: Preliminary Studies
Publikacja -
Analysis of longitudinal wave propagation in a cracked rod by the spectral element method
Publikacja -
A parametric study on water-entry of a twin wedge by boundary element method
Publikacja -
Modal energy identification of large stucture idealised by the finite element method
PublikacjaPrzedstawiono metodę określania energii drgań układów dyskretnych otrzyma-nych w wyniku modelowania metodą elementów skończonych wybranych fragmentów konstrukcji samochodów. W odróżnieniu od poprzednio stosowanych podejść, ro-zważa się całkowite energie mechaniczne odpowiadające poszczególnym posta-ciom drgań własnych. Całkowitą energię mechaniczną oblicza się na podstawie parametrów modelu modalnego. Energię mechaniczną można...
-
Analysis of unsteady pipe flow using the modified finite element method
PublikacjaW pracy przedstawiono rozwiązanie równania przepływu nieustalonego zmodyfikowaną metodą elementów skończonych. Podejście to prowadzi do 6-punktowego schematu niejawnego z dwoma parametrami wagowymi. Analiza dokładności wykonana metodą równania zmodyfikowanego wykazała, że zaproponowany schemat zapewnia wyższą dokładność rozwiązania niż inne schematy. Porównanie wyników obliczeń z wynikami eksperymentu fizycznego wskazuje, że ich...
-
Experimental verification of a new method of loop resistance testing in low voltage systems with residual current devices
PublikacjaA periodical verification of the effectiveness of protection against electric shock shall be performed in low voltage systems. The scope of this verification includes loop impedance/resistance testing. If a residual current device is installed in a tested circuit, this testing is problematic. A residual current device trips out during the test, because of the high value of measurement current. This precludes the execution of the...
-
An Efficient Framework For Fast Computer Aided Design of Microwave Circuits Based on the Higher-Order 3D Finite-Element Method
PublikacjaIn this paper, an efficient computational framework for the full-wave design by optimization of complex microwave passive devices, such as antennas, filters, and multiplexers, is described. The framework consists of a computational engine, a 3D object modeler, and a graphical user interface. The computational engine, which is based on a finite element method with curvilinear higher-order tetrahedral elements, is coupled with built-in...
-
Discussion on “Coupled effective stress analysis of insertion problems in geotechnics with the Particle Finite Element Method” by L. Monforte, M. Arroyo, J.M. Carbonell, and A. Gens
PublikacjaAddressed here is the Particle Finite Element Method (PFEM) modelling of undrained CPTu penetration with regard to a reference analytical solution based on the Spherical Cavity Expansion Method (SCEM). Also discussed is the choice of the soil model and its parameters. The effect of cone interface friction on CPTu simulation is analyzed in a series of penetration tests using Arbitrary Lagrangian-Eulerian (ALE) and Updated Lagrangian...
-
Comparison of modal and finite-element methods in the vibrational analysis of marine propulsion systems
PublikacjaW okrętowych układach napędowych występują dwa typy części składowych. Pierwszym z nich są odcinki wałów, które należą do elementów o ciągłym rozkładzie własności masowych, sprężystych i tłumiących oraz elementy o parametrach skupionych, do których można zaliczyć śrubę napędową, tarcze sprzęgieł i inne. W pracy porównano dwie metody modelowania takich układów. Pierwsza z nich związana jest z tworzeniem modeli przybliżonych w oparciu...
-
Modeling of a rock fall using the discrete element method and study of the seismic signal
PublikacjaMechanizm dużego spadającego bloku skalnego lub lawiny pozostaje nadal słabo rozpoznany zarówno w zakresie pęknięć jak i procesów propagacji. Jedynie ilościowe dane, które aktualnie są mierzone i uchwytne podczas spadania skały, zarejestrowane są jako sejsmiczne sygnały przez szereg sejsmografów. Właściwości sygnału (amplituda, trwanie, częstotliwość) są wyraźnie powiązane z cechami spadania (masa, wysokość spadania, odległość...
-
FEM (Finite Element Method) Numeric Analyses of the Syrenka S201 Car Model
Publikacja -
Modeling of a rock fall using the discrete element method and study of the seismic signal
PublikacjaW artykule przedstawiono opis fal sejsmicznych, zastosowanie dyskretnej metody elementów do opisu obrywu skalnego, opis programów obliczeniowych oraz obliczenia numeryczne wg. podanych programów obliczeniowych.
-
Application of extended Finite Element Method to cracked concrete elements - numerical aspects
PublikacjaArtykuł omawia zastosowanie rozszerzonej metody elementów skończonych do zarysowanych elementów betonowych. Obliczenia wykonano dla elementów poddanych zginaniu i mieszanemu ściskaniu - rozciąganiu. Wyniki porównano z doświadczeniami.
-
A Method for The Assessing of Reliability Characteristics Relevant to an Assumed Position-Fixing Accuracy in Navigational Positioning Systems
PublikacjaThis paper presents a method which makes it possible to determine reliability characteristics of navigational positioning systems, relevant to an assumed value of permissible error in position fixing. The method allows to calculate: availability , reliability as well as operation continuity of position fixing system for an assumed, determined on the basis of formal requirements - both worldwide and national, position-fixing accuracy....
-
A coupled constitutive model for fracture in plain concrete based on continuum theory with non-local softening and eXtended Finite Element Method
PublikacjaThe paper presents a constitutive model for concrete which combines a continuous and discontinuous fracture description. In a continuum regime, two different constitutive laws were used. First, a plasticity model with a Rankine failure criterion and an associated fl ow rule was used. Second, a constitutive law based on isotropic damage mechanics was formulated. In order to capture the width of a localized zone and to obtain mesh-independent...
-
Optimization of the Hardware Layer for IoT Systems using a Trust Region Method with Adaptive Forward Finite Differences
PublikacjaTrust-region (TR) algorithms represent a popular class of local optimization methods. Owing to straightforward setup and low computational cost, TR routines based on linear models determined using forward finite differences (FD) are often utilized for performance tuning of microwave and antenna components incorporated within the Internet of Things systems. Despite usefulness for design of complex structures, performance of TR methods...
-
A New Method of Noncausal Identification of Time-varying Systems
PublikacjaThe paper shows that the problem of noncausal identification of a time-varying FIR (finite impulse response) sys- tem can be reformulated, and solved, as a problem of smoothing of the preestimated parameter trajectories. Characteristics of the smoothing filter should be chosen so as to provide the best trade- off between the bias and variance of the resulting estimates. It is shown that optimization of the smoothing operation can...