Filters
total: 1535
-
Catalog
displaying 1000 best results Help
Search results for: DRILLING ROTATION, MIXED ELEMENT, SHELL ELEMENT
-
Study of displacements of a bridge abutment using FEM
PublicationSteel sheet piles are often used to support excavations for bridge foundations. When they are left in place in the permanent works, they have the potential to increase foundation bearing capacity and reduce displacements; but their presence is not usually taken into account in foundation design. In this article, the results of finite element analysis of a typical abutment foundation, with and without cover of sheet piles, are presented...
-
OPTICAL STRAIN MEASUREMENT OF CONCRETE VERSUS MANUAL EXTENSOMETER MEASUREMENT BASED ON THE TEST RC DEEP BEAM IN A COMPLEX STATE OF STRESS
PublicationThe purpose of this study is to compare the strain measurement techniques of concrete in R-C element subjected to the monotonic load up to the failure. In the analysis manual extensometer methods of measurements and the optical system ARAMIS for non-contact three-dimensional measurements of deformation was used. The test sample was a cantilever deep beam loaded throughout the depth which was a part of the reinforced concrete deep...
-
Comparison of Compact Reduced Basis Method with Different Model Order Reduction Techniques
PublicationDifferent strategies suitable to compare the performance of different model order reduction techniques for fast frequency sweep in finite element analysis in Electromagnetics are proposed and studied in this work. A Frobenius norm error measure is used to describe how good job a reduced-order model is doing with respect to the true system response. In addition, the transfer function correct behavior is monitored by studying the...
-
Discussion on “Dynamic soil-structure interaction: A three-dimensional numerical approach and its application to the Lotung case study”. Poor performance of the HSS model
PublicationThe Hardening Soil Small (HSS) is a constitutive model being extension to the well established Hardening Soil Model (HS) accounting for the nonlinearity of small strain stiffness. It is implemented in commercial finite element computer codes for geotechnical analyses and used widely in research and design. The article deals with a problem known as overshooting after very small load reversals. It induces much higher stiffness than...
-
Diagnostics of historic columns using wave propagation
PublicationThis paper presents a numerical analysis of elastic wave propagation in columns of historical buildings for diagnostics purposes. Numerical calculations were performed using the finite element method in the Abaqus software package. The analysis was carried out for three types of brick columns: a full column, a column filled with debris, and a column empty inside. The excitation was in the form of a wave packet and signals of propagating...
-
Modeling of Human Tissue for Medical Purposes
PublicationThe paper describes the possibilities offered for medicine by modeling of human tissue using virtual and augmented reality. It also presents three proposals of breast modeling for the use in clinical practice. These proposals are the result of arrangements of medical and computer scientists team (the authors) and will be pursued and implemented in the near future. There is included also a brief description of the most popular methods...
-
Young’s modulus distribution in the FEM models of bone tissue
PublicationThis paper presents how differences of Young’s modulus in adjacent finite elements typical for organic materials such as bone tissue, influence stress calculating. Emphasizing high computational cost of variable Young’s modulus in parts of the model, where the number of finite elements has been raised, the authors wants to prove that new model of finite element which has variable Young’s modulus in its volume needs to be created....
-
Experimental and numerical study on damage detection in an L-joint using guided wave propagation
PublicationW pracy zaprezentowano metodę wykrywania i lokalizacji uszkodzeń w konstrukcji ramowej za pomocą podłużnych i poprzecznych fal sprężystych. Przeprowadzono badania numerczyne i eksperymentalne na modelu bez uszkodzenia oraz na modelu z wsprowadzonym nacięciem. Do modelowania zastosowano metodę elementów spektralnych. W pracy przedstawiono sformułowanie nowego element spektralnego dla ram płaskich bazującego na teorii pręta Mindlina...
-
VOF-DEM-FEM combined model of the reef breakwater collapse
PublicationZespolony model numeryczny (metoda modelowania przepływu ze swobodną powierzchnią rozdziału faz ciekłej i gazowej w siatce nieruchomej (ang. Volume of Fluid - VOF, metoda elementów dyskretnych (ang. Distinct Element Method, metoda elementów skończonych (MES)) został wykorzystany do zbadania odkształceń falochronu narzutowego i jego piaszczystego podłoża w wyniku oddziaływania falowania powierzchniowego. Wyniki analizy numerycznej...
-
FEM approach to estimate the behaviour of biocomposite metal-surface coating system
PublicationA three dimensional (3D) model of biocomposite metal-surface coating system, which is influenced byknown external forces, is proposed. This model consists of the metallic substrate (Ti6Al4V) and thehydroxyapatite (HA) coating. Using FEM (finite element method), strain-stress maps of model weregenerated for investigating relations between the extreme stress of HA coating and the magnitude ofexternal force and the thickness of the...
-
The influence of durable contact on human tissue on austenitic biomaterials behaviour
PublicationBadania opierają się na studium pojedynczego przypadku dwoch wkrętów ze stali austenitycznej, które były implantowane do organizmu człowieka jako element łączący złamaną kość piszczelową. Oba wkręty zostały zostały wkręcone w jednakowych warunkach, na okres 1 roku, po którym miały zostać wyjęte. Na skutek komplikacji życiowej nosiciela, wkręty te zostały usunięte dopiero podczas zabiegu po okresie 8 lat.
-
Synthesis and ionophoric properties of functionalized p-tert-butyl-calix[4]arenes
PublicationProjektowanie struktury związków o właściwościach jonoforowych stanowi ważny element chemii supramolekularnej. W pracy przedstawiono wyniki badań nad funkcjonalizacją makrocyklicznych kaliks[4]arenów prowadzacą do nowych związków o zróżnicowanych właściwościach kompleksujących. Syntezowane przez nas jonofory badane były w membranowych elektrodach jonoselektywnych. Wyznaczono potencjometryczne współczynniki selektywności oraz stałe...
-
Determination of equivalent circuit parameters of an induction motor using field calculation software
PublicationSimulation of the drive system comprising a power electronic converter and an induction motor requires that the equivalent circuit parameters of the motor are known. These parameters can be either measured or calculated. A method of calculation of self and mutual inductances that are parameters of a polyphase model of the motor is presented in the paper. All self-inductances and mutual inductances have been calculated using the...
-
Electromagnetic Simulations with 3D FEM and Intel Optane Persistent Memory
PublicationAbstract—Intel Optane persistent memory has the potential to induce a change in how high-performance calculations requiring a large system memory capacity are conducted. This article presents what this change may look like in the case of factorization of large sparse matrices describing electromagnetic problems arising in the 3D FEM analysis of passive highfrequency components. In numerical tests, the Intel oneAPI MKL PARDISO was...
-
Szkolenia w Bibliotece PG
PublicationW dobie zachodzących przemian w świecie nauki studenci i kadra akademicka mierzą się z dużymi wyzwaniami. Naukowcy muszą nie tylko starać się o finansowanie projektów, prowadzić badania i prezentować swoje wyniki w publikacjach naukowych oraz na konferencjach, ale również aktywnie promować swój dorobek naukowy. Efektywne korzystanie z narzędzi komunikacji naukowej stanowi obecnie niezwykle ważny element działalności każdego badacza.
-
Study of the influence of thermal factors on the welding process of polyethylene gas pipelines,
PublicationA one-dimensional calculation scheme is proposed with the help of which it is possible to determine and set the technological parameters with the accuracy to be realized in production conditions: the temperature of the heating element and the heating time, which allows maximum mechanization of the technological operations of polyethylene gas pipelines welding. The numerical value of the coefficient of temperature for polyethylene...
-
The equivariant spectral flow and bifurcation of periodic solutions of Hamiltonian systems
PublicationWe define a spectral flow for paths of selfadjoint Fredholm operators that are equivariant under the orthogonal action of a compact Lie group as an element of the representation ring of the latter. This G-equivariant spectral flow shares all common properties of the integer valued classical spectral flow, and it can be non-trivial even if the classical spectral flow vanishes. Our main theorem uses the G-equivariant spectral flow...
-
A Loophole of All ‘Loophole-Free’ Bell-Type Theorems
PublicationBell’s theorem cannot be proved if complementary measurements have to be represented by random variables which cannot be added or multiplied. One such case occurs if their domains are not identical. The case more directly related to the Einstein–Rosen–Podolsky argument occurs if there exists an ‘element of reality’ but nevertheless addition of complementary results is impossible because they are represented by elements from different...
-
Capacity analysis of the selected track system in partially ordered space
PublicationA proper location of the interval sections has significant impact on the traffic flow in the railway track network. This issue is critical during line modernization as well as when a new solution accounting for the traffic forecast at particular element of the railway track network is developed . However, the situation is more complex and more expensive for railway stations since improvement of the capacity requires critical organizational...
-
Viscous versus electromagnetic damping – amplification in a neighbourhood of a mechanism singular position
PublicationIn the paper, damping of vibrations are considered and compared in a mechanical and in a electromechanical system. In the system, a continuous beam is considered as the main vibrating element. The compared dissipations methods are based on: viscous dampers and DC generators. To increase the possible damping effectiveness, velocity amplification is proposed, i.e., a mechanism is introduced between the beam and the damping element....
-
Extremal thermal loading of a bifurcation pipe
PublicationThe subject of considerations is a spherical bifurcation pipe of a live steam made of steel P91, which is an element of a block of coal-fired power plant working with a 18K370 turbine. As experience shows, it is a very sensitive element of the boiler pipelines. An extreme work scenario for such a block has been adopted, in which the turbine is shutting down to a warm state three times in 24 hours. This is an action dictated by...
-
Sperm segmentation and abnormalities detection during the ICSI procedure using machine learning algorithms
Publication(1) About 15-20% of couples struggle with the problem of infertility. 30 to 40% of these cases are caused by abnormalities in the structure and motility of sperm. Sometimes the only possibility for such people is to use the procedure of artificial insemination. CASA systems are used to increase the efficiency of this procedure by selecting the appropriate sperm cell. (2) This paper presents an approach to the sperm classification...
-
Synteza układu sterowania statkiem morskim dynamicznie pozycjonowanym w warunkach niepewności
PublicationNiniejsza monografia obejmuje zagadnienia związane z syntezą układu dynamicznego pozycjonowania statku w środowisku morskim z zastosowaniem wybranych nieliniowych metod sterowania. W ramach pracy autorka rozważała struktury sterowania z zastosowaniem wektorowej adaptacyjnej metody backstep oraz metod jej pokrewnych, takich jak regulatory MSS (ang. multiple surface sliding), DSC (ang. dynamic surface control), NB (ang. neural backstepping)....
-
Method of selective fading as a educational tool to study the behaviour of prestressed concrete elements under excess loading
PublicationPrestressed structures are a key to realization of the boldest architectural ideas, characteristic feature of prestressed structure is better use of concrete material properties by insertion of internal forces. Learning about pre-stressed reinforced concrete structures is an integral part of Graduate Studies Program in construction engineering. Know-how of geometry change patterns in prestressed concrete elements under certain...
-
Żegluga towarowa na Wiśle
PublicationKoncepcje rozwoju drogi wodnej WISŁY.Bariery utrudniaące rozwój transportu wodnego i przesłanki przemawiające za aktywizacją dróg wodnychb w Polsce.Propozycja drogi wodnej na Wiśle jako elementu łańcucha transportowego z terminalami kontenerowymi w porcie Gdańskim, Bydgoszczy,Warszawie oraz docelowo w rejonie Krakowa jako elementu przyszłego kanału Śląskiego. Koncepcja centrum logistycznego w Bydgoszczy
-
PROBLEMS OF EXPERIMENTAL DETERMINATION OF COEFFICIENTS OF THE WEAR OF SHIP PIPING SYSTEMS
PublicationThe article presents series of considerations relating to experimental evaluation of the reliability of ship piping systems. The aim of this study is to attempt to answer the following questions: What should be the tested element? How to choose the diameter of the tested item? What should be the result of measurements and calculations? How to measure? How to choose the duration of the test? How to choose the sample size and elaborate...
-
Numerical and experimental investigation of rotational stiffness of zed-purlins connection with sandwich panels
PublicationA rotational resistant stiffness of the zed-purlins connection with sandwich panels is investigated. A simple finite element method model of the connection is proposed. The numerical analysis of the model performed by ABAQUS software, in physically linear and geometrically nonlinear ranges, leads to the rotational resistant stiffness sought. The numerical solution obtained is verified experimentally. Two variants of distribution...
-
Calculation of Resonance in Planar and Cylindrical Microstrip Structures Using a Hybrid Technique
PublicationA hybrid technique was employed for the analysis of the resonance frequency of thin planar and cylindrical microstrip structures with the patches of arbitrary geometry. The proposed technique utilizes a combination of Galerkin’s moment method and a finite-element method (FEM). In this approach, an FEM is adopted to calculate the patch surface current densities, and a method of moments is utilized to calculate the resonance frequencies...
-
Model Order Reduction for Problems With Dispersive Surface Boundary Conditions
PublicationThis letter proposes a new scheme for reduced-order finite-element modeling of electromagnetic structures with nonlinear, dispersive surface boundary conditions, which optimally exploits the numerically stable and efficient MOR framework for second-order systems provided by SAPOR method. The presented results of numerical experiments for an example of a waveguide filter demonstrate the superior accuracy of the resulting reduced models...
-
Modelling method for a class of distributed-lumped parameter systems
PublicationThe paper presents an alternative approach for modelling and order reduction of continuous system. The proposed methodology combines application of two methods: the modal decomposition method and the rigid finite element method. The given continuous structure is divided into 1D continuous substructures. For each 1D substructure modal decomposition and reduction procedure is applied. Interactions between substructures are described...
-
Współczynnik wymiarowy Kv w doborze elementów pneumatycznych
PublicationZnanych jest wiele sposobów opisu właściwości przepływowych elementów pneumatycznych. Jednym z nich jest podanie wartości współczynnika wymiarowego Kv zdefiniowanego w normie PN-83/M-74201 (1983). W niniejszej pracy przedstawiono możliwe różnice między wartością przewidywaną a wartością uzyskaną strumienia powietrza przepływającego przez element pneumatyczny w sytuacji, gdy podstawą doboru tego elementu z katalogu była znana dla...
-
Badania deformacji w materiałach sypkich podczas dynamicznego przepływu w silosach
PublicationMonografia stanowi próbę połączenia analizy zagadnień powstawania zmian objętościowych oraz pomiaru zmian koncentracji materialu sypkiego podczas opróżniania silosu. W pracy przedstwiono wyniki pomiarów wykonanych z zastooswaneim metody Particle Image Velocimetry, Electrical Capacitance Toomography oraz promieniowania rentgenowskiego. Zamieszczono równeiz wyniki obliczeń wykoanaych z zastooswaniem metody DEM (Discrete Element...
-
Zastosowanie technik szybkiego prototypowania w optymalizacji konstrukcji wirników pomp
PublicationWykonanie optymalnie skonstruowanego wyrobu wymaga przeprowadzenia badań testowych już na etapie projektowania. Jedną z metod, za pomocą której można wykonać element już w fazie projektowania, jest stereolitografia. Metoda ta opiera się na warstwowej budowie prototypu na bazie polimeryzacji ciekłego fotopolimeru. Nie wymaga ona przy tym zastosowania form odlewniczych, narzędzi i dodatkowych metod obróbkowych, a model wytwarzany...
-
Multi-criteria selection of hydraulic gates
PublicationSelekcja doboru zamknięcia wodnego stanowi podstawowy element w jego projektowaniu. Projektowanie zamknięć można rozważać jako problem krótkoterminowy (zamknięcie natychmiastowe wysokiej wody) jak i problem długoterminowy uwzględniający problemy rolnicze, ekologiczne i zmiany klimatu. W doborze rodzaju zamknięć wodnych należy uwzględnić wiele kryteriów w tym ekonomicznych, wykonawczych, ekologicznych i innych. W pracy przedstawiono...
-
Edge ranking and searching in partial orders
PublicationArtykuł jest poświęcony problemowi konstrukcji optymalnej (wymagającej minimalnej ilości porównań/zapytań) strategii wyszukiwania elementu w częściowym porządku. W pracy wskazano związki pomiędzy tym problemem oraz uporządkowanym kolorowaniem krawędzi grafów, co implikuje liniowy algorytm dla częściowych porządków o strukturze drzewa. Pokazano również, że znalezienie optymalnej strategii jest problemem obliczeniowo trudnym dla...
-
Dynamic risk assessment in autonomous vehicles motion planning
PublicationArguing that an autonomous mobile system is sufficiently safe to operate in presence of other vehicles and objects is an important element in development of such systems. Traditional approach to assure safety is to distinguish between safe and unsafe area and prevent the autonomous vehicle from entering the unsafe area. The paper presents a model of autonomous vehicle control system which uses risk assessment...
-
The large rotations theory of elasto-viscoplastic shells subjected to thedynamic and thermal loads.
PublicationPrzedstawiono problemy sprężysto- lepkoplastycznej analizy geometrycznie nieliniowych płyt i powłok poddanych obciążeniom dynamicznym w różnych temperaturach. W obliczeniach zastosowano teorię ścinania pierwszego rzędu i konstytutywne prawo Chaboche´a w wariantach z uwzględnieniem wpływu temperatury na stałe materiałowe. Do całkowania równań ruchu użyto metody różnic centralnych, a do całkowania równań konstytutywnych regułę...
-
Vibrational Properties of LaNb0.8M0.2O4-δ (M=As, Sb, V, and Ta)
PublicationLaNb0.8M0.2O4-δ (where M=As, Sb, V, and Ta) oxides with pentavalent elements of different ionic sizes were synthesized by a solid-state reaction method. The vibrational properties of these oxides have been investigated. These studies revealed that the substituent element influences both Debye temperature value as well as the Raman active vibrational modes. Additionally, the low-temperature vibrational properties of LaNb0.8Sb0.2O4-δ...
-
Numerical studies on the influence of selected construction features and road conditions on the performance of road cable barriers
PublicationCable barriers are commonly used on Polish roads, including motorways and local roads. Their main elements are pre-stressed wire ropes, which are usually anchored at two ends in concrete blocks buried in the soil. In this work numerical studies concerning the influence of selected construction features and parameters of the vehicle motion on the performance of cable barriers were performed. Numerical simulations are a useful tool...
-
On the influence of the acceleration recording time on the calculation of impact severity indexes
PublicationThe paper concerns with the analysis of normative requirements pertaining to experimental setup of a crash test and its numerical modelling. An overview of parameters describing the collision of a vehicle with a road restraining system is presented. A short description of a concrete road safety barrier is presented. A brief description of numerical modelling procedures for crash tests is given as well. The parametric influence...
-
Hybrid Technique for the EM Scattering Analysis with the Use of Ring Domain Decomposition
PublicationA hybrid technique combining finite-element and mode-matching methods for the analysis of scattering problems in open space is presented here. The main idea is based on impedance matrix descriptions of the boundary surrounding the discrete computational domain and combine it with external field described analytically. The discrete analysis, which is the most time- and memory-consuming, is limited here only to the close proximity...
-
Dynamic Tests and Technical Monitoring of a Novel Sandwich Footbridge
PublicationA novel sandwich composite footbridge is described in this paper, for the first time after it has been put into operation over the Radunia River in the Pruszcz Gdański municipality. This paper presents results of dynamic tests and describes technical monitoring of the footbridge. The dynamic tests were conducted to estimate pedestrian comfort and were compared with the ones from numerical simulations made in the environment of...
-
Integrating Confidence And Assurance Arguments
PublicationTo be considered compelling an assurance case should address its potential deficits, possibly with the use of a confidence argument. Assurance argument and confidence argument should be clearly separated and consistent at the same time. We propose a way of their integration with the use of an element representing rationale for each argumentation strategy. The rationale integrates confidence argument for a given argumentation step...
-
Simulations of wave propagation and attenuation in fields of colliding ice floes
Open Research DataThis dataset contains results of numerical smulations of sea ice-wave interactions, corresponding to laboratory experiments conducted at the Large Ice Model Basin (LIMB) at the Hamburg Ship Model Basin (HSVA) as part of the LS-WICE ("Loads on Structure and Waves in Ice"; https://zenodo.org/record/1067170#.XrLt_dhpxhE) project. THe simulations were conducted...
-
AFM investigation of electrode fabricated by 3D printing
Open Research Data3D printing, also known as additive manufacturing, has enjoyed great interest in recent years due to the versatility of this method of producing various shapes and details. Due to the possibility of precise control of the shape and composition of the printed elements, the discussed technique can be widely used in electrochemistry, including electrochemical...
-
Video traffic data - Interchange Karczemki (S6-501)
Open Research DataThe data includes video traffic data registered with 5 video cameras at weaving area (weaving section type A) of the Karczemki interchange within S6 expressway in Poland (interchange of expressway S6 and regional road 501), located in the Tri-City Agglomeration . The data covers the one day: 10.10.2017 (expressway S6).
-
Video traffic data - Interchange Gdansk Poludnie (S6-S7), Poland
Open Research DataThe data includes video traffic data registered with 8 video cameras at exit and entry lanes of the Gdansk Poludnie interchange within S6 expressway in Poland (interchange of expressway S6 and S7), located in the Tri-City Agglomeration . The data covers the two days: 4.08.2020 and 6.08.2017 (expressway S6).
-
Video traffic data - Interchange Lotnisko (S6-472) - Exit +entry lanes, Poland
Open Research DataThe data includes video traffic data registered with 6 video cameras at entry or exit lanes of the Lotnisko interchange within S6 expressway in Poland (interchange of expressway S6 and regional road 472), located in the Tri-City Agglomeration. The data covers the two days: 10.04.20187 and 12.04.2017(expressway S6).
-
Oceny strategiczne elementem systemu łagodzenia w odniesieniu do krajobrazowych skutków komunikacji drogowej
PublicationArtykuł prezentuje możliwości wykorzystania strategicznych ocen oddziaływania na środowisko jako jednego z elementów systemu łagodzenia negatywnych skutków rozwoju. Za wiodący aspekt wzmocnienia systemu SOOŚ/OOŚ uznano problem łagodzenia skutków środowiskowych, a najważniejszą w tym rolę przypisano krajobrazowi, określonemu jako nośnik informacji o skutkach w poszczególnych, współzależnych od siebie elementach środowiska i za wyznacznik...
-
Investigation on the Sources and Impact of Trace Elements in the Annual Snowpack and the Firn in the Hansbreen (Southwest Spitsbergen)
PublicationWe present a thorough evaluation of the water soluble fraction of the trace element composition (Ca, Sr, Mg, Na, K, Li, B, Rb, U, Ni, Co, As, Cs, Cd, Mo, Se, Eu, Ba, V, Ge, Ga, Cr, Cr, P, Ti, Mn, Zr, Ce, Zn, Fe, Gd, Y, Pb, Bi, Yb, Al, Nb, Er, Nd, Dy, Sm, Ho, Th, La, Lu, Tm, Pr, Tb, Fe, In, Tl) and their fluxes in the annual snowpack and the firn of the Hansbreen (a tidewater glacier terminating in the Hornsund fjord, southwest...