Search results for: beam
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Propagation of elestic waves in beams including damping effects.
PublicationW pracy przedstawiono wyniki analizy propagacji fali sprężystej w belce z tłumieniem wiskotycznym.
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Static analysis of thin-walled beams and frames with stiffeners.
PublicationPraca zawiera pełną treść referatu wygłoszonego na Konferencji w Wilnie.Referat przedstawia problem numerycznej analizy belek i ramstalowych zbudowanych z bi-symetrycznych profili cienkościennychze stężeniami. Wyniki analizy przeprowadzonej według koncepcji superelementu jednowymiarowego porównano z wynikami obliczeń przy zastosowaniu gęstej siatki elementów powłokowych QUAD4 programu MSC NASTRAN.
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Experimental investigations on concrete beams reinforced with CFRP lamellas
PublicationPaper presents experimental investigation made on two concrete beams reinforced with internal Carbon Fibre Reinforced Polymer (CFRP) lamellas (i.e. strips, bands). The reinforcement geometrical arrangement was similar as in normal concrete beams reinforced with steel bars and stirrups. The beams were destroyed by the shear forces, as intended. Obtained load-carrying capacities were lower as expected: below 40% of a calculated value....
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Multipoint Ultrasonic Diagnostics System of Prestressed T-Beams
PublicationThis paper is devoted to the application of ultrasonic wave propagation phenomena for the diagnostics of prestressed, concrete, bridge T-beams. A multi-point damage detection system is studied with use of numerically obtained data. The system is designed to detect the presence of the material discontinuities as well as their location.
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3D DEM simulations of fracture in reinforced concrete beams
PublicationArtykuł dotyczy zachowania się belki żelbetowej bez zbrojenia pionowego przy trzypunktowym zginaniu. Belka uległa zniszczeniu wskutek ścinania z powodu obecności nadmiernego zbrojenia podłużnego. Eksperymenty przeprowadzono w skali laboratoryjnej z wykorzystaniem systemu mikro-CT, a następnie odtworzono je w analizach numerycznych stosując metodą elementów dyskretnych 3D (DEM). Zastosowano 4-fazowy model betonu z mezostrukturą,...
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On the exact equilibrium conditions of irregular shells reinforced by beams along the junctions
PublicationThe exact, resultant equilibrium conditions for irregular shells reinforced by beams along the junctions are formulated. The equilibrium conditions are derived by performing direct integration of the global equilibrium conditions of continuum mechanics. New, exact resultant static continuity conditions along the singular curve modelling reinforced junction are presented. The results do not depend on shell thickness, internal through-the-thickness...
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First natural transverse frequency of truncated cone and wedge beams
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Free torsional vibration sensitivity analysis of thin walled beams.
PublicationW pracy przedstawiono analizę wrażliwości swobodnych drgań skrętnych bisymetrycznej , cienkościennej belki o otwartym przekroju poprzecznym, poddanej działaniu siły osiowej
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Static and sensitivity analysis of thin-walled beams and frames with stiffeners.
PublicationPraca zawiera tekst referatu wygłoszonego w Maastricht. Przedstawiono analizę statyczną oraz analizę wrażliwości belek i ram zbudowanych z cienkościennych elementów, poddanych skręcaniu lub zginaniu ze skręcaniem, z możliwością zastosowania różnego typu stężeń . Wykorzystano technikę superelementu do wyznaczenia macierzy sztywności węzła ramy i elementów ze stężeniami. Otrzymane wyniki dla modelu jednowymiarowego MES porównano...
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Adjoint approach sensitivity analysis of thin-walled beams and frames.
PublicationArtykuł omawia zastosowanie metody układów sprzężonych w numerycznej analizie wrażliwości belek i ram zbudowanych ze stalowych profili cienkościennych poddanych skręceniu lub skręceniu ze zginaniem. Przedstawiono wyniki analizy wrażliwości przemieszczeń i sił wewnętrznych na zmianę parametrów geometrycznych konstrukcji.
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Sensitivity analysis of beams and frames made of thin-walled members
PublicationMonografia dotyczy analizy wrażliwości w problemach statyki układów zbudowanych z prętów cienkościennych. Przedstawiono w niej nowe podejście do modelowania belek i ram z różnego rodzaju stężeniami ograniczającymi spaczenie przekroju poprzecznego, w przypadku skręcenia. Wprowadzono pojęcie superelementu belkowego i węzłowego. Przeprowadzono analizę statyczną belek i ram poddanych skręceniu lub skręceniu ze zginaniem, wzmocnionych...
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Experimental Study of Dapped-End Beams Subjected to Inclined Load
PublicationThis paper presents the results of an experimental investigation of the reinforced concrete (RC) dapped-end beams loaded with inclined forces, compared to identical ones loaded with vertical forces only. Such a load may occur in, for example, Gerber's joints or in dapped-end beams supported on corbels, where the vertical gravitation force is additionally completed with horizontal forces caused by temperature differences, shrinking,...
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Thermal Self-Action of Acoustic Beams Containing Several Shock Fronts
PublicationThermal self-action of an acoustic beam with one discontinuity or several shock fronts is studied in a Newtonian fluid. The stationary self-action of a single sawtooth wave with discontinuity (or some integer number of these waves), symmetric or asymmetric, is considered in the cases of self-focusing and self- defocusing media. The results are compared with the non-stationary thermal self-action of the periodic sound. Thermal self-action...
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Investigations on strength and fracture in RC beams scaled along height or length
PublicationThe objective of the present paper is to identify experimentally and theoretically differing failure mechanisms in reinforced concrete beams subjected to four-point bending for a separate variation of the depth and length at the constant thickness. Experiments were performed on reinforced concrete beams under four-point bending. Different failure mechanisms included steel yielding, diagonal tension or shear- compression depending...
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Storing Matter’technique in SIMS depth profile analysis
PublicationSecondary ion mass spectrometry (SIMS) is a very useful technique for the analysis of layered systems. It is based on the primary ion beam sputtering of solids and mass analysis of the emitted secondary ions. A main limitation of this technique results from the direct quantitative analysis, since the ionization efficiency of a given atom is highly influenced by the neighbouring atoms at the surface. This phenomenon is known as...
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Dissolution of Nb-doped hydroxyapatite prepared via low-temperature mechanochemical method: Spectroscopy studies
PublicationCalcium phosphate glass ceramics with nominal hydroxyapatite stoichiometry doped with niobium were synthesized using simple as well as low-temperature mechanochemical method and then in the form of compressed pellet were submitted to the static dissolution process in distilled water for one month. The results of structural analysis, performed mainly on the base of spectroscopic methods such as: infrared absorption spectroscopy,...
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Annihilation rates of low-energy positron scattering from simple diatomic molecules
PublicationWe discuss the calculations of Zeff coefficients for a series of diatomic molecules over the range of energies below the positronium formation. During the development of a general code for polyatomic, nonlinear molecules colliding with positrons, it was discovered that the earlier one, employed only for diatomic molecules, had an error. The error is corrected and the corrected results are presented here. We also discuss a way of...
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Correlation–polarization effects in electron/positron scattering from acetylene: A comparison of computational models
PublicationDifferent computational methods are employed to evaluate elastic (rotationally summed) integral and differential cross sections for low energy (below about 10 eV) positron scattering off gas-phase C2H2 molecules. The computations are carried out at the static and static-plus-polarization levels for describing the interaction forces and the correlation–polarization contributions are found to be an essential component for the correct...
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Polarisation effects in low-energy positron–molecule scattering
PublicationThe UK molecular R-matrix method has been adapted to treat positron collisions from polyatomic targets. A simple empirical enhancement factor which corrects for the underestimation of electron–positron polarisation and correlation effects in the calculations performed with the static-plus-polarization model at low scattering energies is presented. Application of this model to positron scattering from carbon dioxide at energies...
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Individual contributions of M X-ray line from Cu- and Co-like tungsten ions and L X-ray line from Ne-like molybdenum ions – Benchmarks for new approach to determine the high-temperature tokamak plasma parameters
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Energy shift of the Lβ2 line as an ionization diagnostic for the dense plasma in the PFRP
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Modeling of soft N, M and L X-ray lines from tungsten relevant to plasma parameters in the WEST tokamak
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Theoretical Auger and photoionization studies for open shell atoms andions.
PublicationWykorzystano program komputerowy RATIP do badań własności atomów i jonów o dowolnej konfiguracji. Położono nacisk na obliczenia szeregu własności elektronów Augera i fotojonizacji, aby dokonać porównań z ostatnio wykonywanymi doświadczeniami.
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Elastic cross-section calculations for electron collisions with XY4 (X=Si,Ge; Y=H, F, Cl, Br, I) molecules
PublicationObliczano elastyczne przekroje czynne dla tetraedrycznych związków krzemu i germanu. Otrzymane wyniki porównano z innymi dostępnymi wynikami obliczeń oraz z danymi doświadczalnymi; dla energii powyżej 100 eV uzyskano zadowalającą zgodność.
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Nano-structured Pt embedded in acidic salts of heteropolymolybdate matrices: MS EXAFS study
PublicationA structural study of Pt nano-catalysts is presented in the paper. The innovation in the case of the considered catalytic materials resides in the use a meso-microporous inorganic matrix of heteropolyacid salt of composition X2.5H0.5YMo12O40 where X = Rb, Cs and Y = P, Si as a catalyst support. Metallic nanoparticles were created by platinum ions reduction in a hot H2/Argon stream and were mainly located into matrix pores. As the...
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A Diagnostic Method Based on Deflection Analysis for Monitoring Post-elastic Response of Beams
PublicationA non-destructive diagnostic method based on deflection analysis for monitoring the post-elastic response of beams was developed, and a diagnostic indicator was proposed. The indicator was defined as the second moment of the normalised curvature function about the mid-span, where the curvature was computed from the normalised deflection function. Elastic reference values of the indicator were computed for simply supported beams...
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The method of analysis of damage reinforced concrete beams using terrestial laser scanning
PublicationThe authors present an analysis of the possibility to assess deformations and mechanisms of destructing bent reinforced concrete beams using the terrestrial laser scanning. As part of the experiments carried out at the Regional Laboratory of Construction of the Concrete Structures Division of the Civil and Environmental Engineering Faculty at Gdansk University of Technology, the reinforced concrete beams were subjected to destruction...
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THE METHOD OF ANALYSIS OF DAMAGE REINFORCED CONCRETE BEAMS USING TERRESTRIAL LASER SCANNING
PublicationThe authors present an analysis of the possibility to assess deformations and mode of failure of R-C beams using terrestrial laser scanning. As part of experiments carried out at the Regional Laboratory of Construction (at Gdansk University of Technology), reinforced concrete beams were subjected to destruction by bending and by shear. The process of press impact on the reinforced concrete beam was recorded using terrestrial laser...
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Surface texture of pine wood beams after planing in industrial conditions
PublicationMeasuring the surface features of wooden components after planing is connected with the rising demands regarding to the quality of the painted window frames. In the paper the complex surface texture analysis especially identifying of surface damages using non-contact 3D measurement techniques for precise area measurement were presented.This enabled the study of irregular surface features with sufficient fidelity and resolution....
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Experimental Verification of Natural Vibration Models of Steel-concrete Composite Beams
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Debonding Detection in Reinforced Concrete Beams with the Use of Guided Wave Propagation
PublicationOne of the most frequent damage of the reinforced concrete structures is debonding between steel bar and concrete cover. In the case of debonding occurrence not only the strength of the structure decreases, but also it is more vulnerable to corrosion damages. For this reason fast and effective methods of debonding detection in an early stage of its development need a significant boost. The paper presents analytical and experimental...
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Cavitation erosion of steels processed by CO2 laser beams of various parameters.
PublicationPrzedstawiono wpływ parametrów przetapiania stali za pomocą wiązki lasera CO2 na jej własności kawitacyjne. Do badań użyto stali 45, 2H13 i OH18N9. Wyniki badań wskazują na znaczny wpływ parametrów przetapiania na poziom odporności kawitacyjnej stali.
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Identification of discontinuites in composite rods and beams based on Lamb wave propagation
PublicationW pracy omówiono metodę identyfikacji typu nieciągłości w belkach i prętach kompozytowych, oparta o analizę zmain w propagacji fali Lamba.
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RMS-based damage detection in reinforced concrete beams: numerical simulations
PublicationImage-based damage detection methods using guided waves are well known and widely applied approaches in structural diagnostics. They are usually utilized in detection of surface damages or defects of plate-like structures. The article presents results of the study of applicability of imaging wave-based methods in detection in miniscule internal damage in the form of debonding. The investigations were carried out on numerical models...
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Investigation of influence of space mopdes interaction on nonlinear dynamics of sound beams
PublicationOperatory rzutu na mody są zdefiniowane w dynamice płynów trójwymiarowych. Zostały wyprowadzone równania ewolucyjne. Rezultaty obliczeń numerycznych przedstawione.
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BEHAVIOR OF REINFORCED CONCRETE BEAMS CONTAINING LIGHTWEIGHT AGGREGATE IN THE TENSILE ZONE
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Structural Assessment of Reinforced Concrete Beams Incorporating Waste Plastic Straws
PublicationThe behavior of reinforced concrete beams containing fibers made of waste plastic straws (WPSs) under the three point bending test is examined. The effect of WPS fiber addition on the compressive and split tensile strength is reported. Four concrete mixes were prepared. The control mix PS-0 had a proportion of 1 cement: 1 sand: 2 coarse aggregate and a water cement ratio of 0.4. In the other three mixes PS-0.5, PS-1.5 and PS-3,...
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Damage detection in beams using wavelet transform on higher vibration modes
PublicationNiniejsza praca poświęcona jest technice diagnostyki konstrukcji bazującej na transformacie falkowej. Badany obiekt to belka wspornikowa z uszkodzeniami w formie nacięcia o głębokości 20%, 10% oraz 5% wysokości belki. Pomiary postaci drgań wykonano za pomocą nowoczesnego wibrometru laserowego. Celem pracy jest przedstawienie eksperymentalnych i numerycznych analiz wpływu wyższych postaci drgań na efektywność wykrywania uszkodzeń...
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Discussion - Experimental study of dapped–end beams subjected to inclined load
PublicationDiscussion - Experimental study of dapped–end beams subjected to inclined load
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Experimental investigations of size effect in reinforced concrete beams failing by shear
PublicationW artykule omówiono wyniki doświadczalne efektu skali w zbrojonych betonowych belkach niszczących się przez ścinanie. Doświadczenia wykonano dla belek o różnych wymiarach ze zbrojeniem stalowym i bazaltowym. Podczas doświadczeń pomierzono siłę oraz szerokości lokalizacji i rys. Wyniki porównano z modelem skali wg Bazanta.
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Multi-scale modelling of concrete beams subjected to three-point bending
PublicationW artykule przedstawiono wyniki numeryczne MES dwuskalowego modelowania belek betonowych z nacięciem na poziomie skali makro i mezo. Obliczenia wykonano przy wykorzystaniu modelu degradacji sztywności z nielokalnym osłabieniem. Beton został opisany na poziomie skali mezo jako stochastyczny materiał 3-składnikowy złożony z kruszywa, zaczynu cementowego oraz stref kontaktu. Natomiast na poziomie skali makro został opisany jako materiał...
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Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams
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Neutral Dissociation of Pyridine Evoked by Irradiation of Ionized Atomic and Molecular Hydrogen Beams
PublicationThe interactions of ions with molecules and the determination of their dissociation patterns are challenging endeavors of fundamental importance for theoretical and experimental science. In particular, the investigations on bond-breaking and new bond-forming processes triggered by the ionic impact may shed light on the stellar wind interaction with interstellar media, ionic beam irradiations of the living cells, ion-track nanotechnology,...
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An isogeometric finite element formulation for geometrically exact Timoshenko beams with extensible directors
PublicationAn isogeometric finite element formulation for geometrically and materially nonlinear Timoshenko beams is presented, which incorporates in-plane deformation of the cross-section described by two extensible director vectors. Since those directors belong to the space R3, a configuration can be additively updated. The developed formulation allows direct application of nonlinear three-dimensional constitutive equations without zero...
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Unusual dynamics and nonlinear thermal self-focusing of initially focused magnetoacoustic beams in a plasma
PublicationUnusual thermal self-focusing of two-dimensional beams in plasma which axis is parallel to the equilibrium straight magnetic field is considered. The equi- librium parameters of plasma determine scenario of a beam divergence (usual or unusual) which is stronger as compared with a flow without magnetic field. Nonlinear thermal self-action of a magnetosonic beam behaves differently in the ordinary and unusual cases. Damping of wave...
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Performance of isotropic constitutive laws in simulating failure mechanisms in scaled RC beams
PublicationResults of numerical calculations of reinforced concrete (RC) beams are presented. Based on experimental results on longitudinally reinforced specimens of different sizes and shapes are investigated. Four different continuum constitutive laws with isotropic softening are used: one defined within continuum damage mechanics, an elasto-plastic with the Rankine criterion in tension and the Drucker-Prager criterion in compression, a...
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Assessment of Wooden Beams from Historical Buildings Using Ultrasonic Transmission Tomography
PublicationThe main goal of this study was non-destructive evaluation of wooden elements using ultrasonic waves. The inspection was carried out on wooden beams from a historical object. Elastic wave signals were processed by ultrasonic transmission tomography to obtain imaging of the internal structure of tested elements without disturbing their state and integrity. The focus was on the influence of wood anisotropy on the propagation of ultrasonic...
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Nonlocalized thermal behavior of rotating micromachined beams under dynamic and thermodynamic loads
PublicationRotating micromachined beams are one of the most practical devices with several applications from power generation to aerospace industries. Moreover, recent advances in micromachining technology have led to huge interests in fabricating miniature turbines, gyroscopes and microsensors thanks to their high quality/reliability performances. To this end, this article is organized to examine the axial dynamic reaction of a rotating...
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Time Projection Chamber (TPC) detectors for nuclear astrophysics studies with gamma beams
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Spectral criterion of infinite fatigue life of beams under asymmetric random loads
PublicationRozpatrywana jest trwałość zmęczeniowa belek poddanych stałym i zmiennym obciążeniom osiowym, giętnym i skrętnym o znanych gęstościach widmowych mocy. Założono, że materiał posiada granicę zmęczenia i jest zgodny z modelem Kelvina-Voigta, oraz że składowe naprężenia są stacjonarne, stacjonarnie skorelowane i różniczkowalne w sensie średniokwadratowym. Zdefiniowano naprężenie równoważne i sformułowano kryterium nieograniczonej trwałości...
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Spectral criterion of infinite fatigue life of beams under combined random loads
PublicationRozpatrywana jest trwałość zmęczeniowa belek poddanych zmiennym obciążeniom osiowym, giętnym i skrętnym o znanych gęstościach widmowych mocy i zerowych wartościach średnich. Założono, że materiał posiada granicę zmęczenia i jest zgodny z modelem Kelvina-Voigta, oraz że składowe naprężenia są stacjonarne, stacjonarnie skorelowane i różniczkowalne w sensie średniokwadratowym. Zdefiniowano naprężenie równoważne i sformułowano kryterium...
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Experimental Tests Of Sandwich Beams In The Design Process Of GFRP Shell Footbridge Structure
PublicationThe paper includes selected aspects of the study to elaborate architectural, material and construction design of pedestrian footbridge spans made of composite materials. The considered footbridge is a sandwich-type shell structure. The cooperation of PET foam core with outer lining surfaces is crucial for its load bearing capacity. The paper is aimed to experimental investigation of sandwich beams subjected to bending loading....
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Static analysis of grids assembled with thin-walled beams of the open cross-section
PublicationPraca dotyczny analizy statycznej rusztów zbudowanych z prętów cienkościennych. Przedstawiono w niej koncepcję metody modelowania konstrukcji dźwigarów cienkościennych i rusztów z wykorzystaniem superelementów w połączeniu z klasyczną teorią belek cienkościennych o przekroju nieodkształcalnym. Zamieszczono wyniki przeprowadzonej eksperymentalnej weryfikacji badań teoretycznych.
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SIMULATIONS OF FRACTURE IN CONCRETE BEAMS UNDER BENDING USING A CONTINUUM AND DISCRETE APPROACH
PublicationThe paper describes two-dimensional meso-scale results of fracture in notched concrete beams under bending. Concrete was modelled as a random heterogeneous 4-phase material composed of aggregate particles, cement matrix, interfacial transitional zones and air voids. Within continuum mechanics, the simulations were carried out with the finite element method based on a isotropic damage constitutive model enhanced by a characteristic...
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Measurements and calculations of the width of the fracture process zones on the surface of notched concrete beams
PublicationArtykuł omawia wyniki pomiaru i analizy numerycznej szerokości strefy pękania w belkach betonowych z nacięciem. Do pomiarów zastosowano metodę DIC. Do symulacji zastosowano model sprężysto - plastyczny i model z degradacją sztywności. Oba modele zostały rozszerzone o nielokalne osłabienie. Wyniki symulacji porównano z doświadczeniami.
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Experimental and numerical investigations on RC beams with stirrups scaled along height or length.
PublicationBelki żelbetowe (RC) ze zbrojeniem poprzecznym (strzemiona) poddane czteropunktowemu zginaniu zostały zbadane eksperymentalnie i numerycznie. Belki były skalowane wzdłuż wysokości lub długości. Były przezbrojone, aby uniknąć płynięcia zbrojenia podłużnego. W pierwszej kolejności przeprowadzono badania laboratoryjne na belkach żelbetowych ze strzemionami. Ze względu na brak podobieństwa geometrycznego zaobserwowano dwa odrębne tryby...
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Application of twin-plane ECT sensor for identification of the internal imperfections inside concrete beams
PublicationThe main purpose of this paper is to investigate application of special construction of Electrical Capacitance Tomography (ECT) sensor to concrete beams internal homogeneity tests. Identification of internal imperfection inside the concrete beams is one of the main problems related to analysis of the construction structure bearing capacity. Therefore, this paper shows attempts to study the measurement prospects for this non-invasive,...
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NON-STATIONARY THERMAL SELF-ACTION OF ACOUSTIC BEAMS CONTAINING SHOCK FRONTS IN THERMOCONDUCTING FLUID
PublicationNon-stationary thermal self-action of a periodic or impulse acoustic beam containing shock fronts in a thermoconducting Newtonian fluid is studied. Self-focusing of a saw-tooth periodic and impulse sound is considered, as well as that of a solitary shock wave which propagates with the linear sound speed. The governing equations of the beam radius are derived. Numerical simulations reveal that the thermal conductivity weakens the...
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Failure characterisation of sandwich beams using integrated acoustic emission and digital image correlation techniques
PublicationThe paper presents the experimental study of the failure behaviour of sandwich beams subjected to bending. The samples examined are sandwich beams made of polyethylene terephthalate foam core and glass fibre-reinforced polymer laminate face sheets. In a series of experiments, it has been proposed to integrate diagnostic techniques with acoustic emission and digital image correlation to accurately track the cracking process on the...
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Fatigue Performance of Double-Layered Asphalt Concrete Beams Reinforced with New Type of Geocomposites
PublicationThe reinforcement of asphalt layers with geosynthetics has been used for several decades, but proper evaluation of the influence of these materials on pavement fatigue life is still a challenging task. The presented study investigates a novel approach to the reinforcement of asphalt layers using a new type of geogrid composite, in which square or hexagonal polypropylene stiff monolithic paving grid with integral junctions is bonded...
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Laboratory fatigue assessment of large geocomposite-reinforced double-layered asphalt concrete beams
PublicationGeosynthetic reinforcement of asphalt layers has been used for several decades. Evaluation of the influence of these materials on pavement fatigue life is still ongoing, especially for new types of geocomposites. This paper presents the evaluation of fatigue performance of large asphalt concrete beams reinforced with a new type of composite in which square or hexagonal polypropylene stiff monolithic paving grid with integral junctions...
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Using the ultrasonic tomography method to study the condition of wooden beams from historical buildngs
PublicationThe need to evaluate the integrity of wooden structural elements is constantly increasing. Non-destructive methods are becoming more popular in this field of research. One type of non-destructive testing is the ultrasonic imaging method, which allows the analysis of internal wood structures without disturbing their state and integrity. In this study, we are interested in assessing the effect of wood condition on the ultrasound...
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Verification of selected calculation methods regarding shear strength in beams without web reinforcement
PublicationThe purpose of the article was to compare selected calculation methods regarding shear strength in reinforced concrete beams without web reinforcement. Several calculation methods were tested. This included codes: PN-EN 1992-1-1:2008, ACI 318-14 and fib Model Code for Concrete Structures 2010. The analysis also consists of authorial methods published in technical literature. Calculations of shear strengths were made based on experimental...
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Application of continuous wavelet transform in vibration based damage detection method for beams and plates
PublicationW artykule zaprezentowano metodę lokalizacji uszkodzeń w konstrukcjach belkowych i płytowych bazującą na analizie falkowej. Wyznaczono postacie drgań badanych konstrukcji. Postacie drgań konstrukcji belkowej zostały przeanalizowane jednowymiarową transfrormatą falkową. Sformułowano dwuwymiarową transformatę falkową, którą zastosowano do postaci drgań konstrukcji płytowej.
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Application of continuous wavelet transform in vibration based damage detection method for beams and plates
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Verification of Selected Calculation Methods Regarding Shear Strength in Reinforced and Prestressed Concrete Beams
PublicationThe purpose of this article was an attempt to compare selected calculation methods regarding shear strength in reinforced and prestressed concrete beams. Several calculation methods were tested. This included codes: PN-EN 1992-1-1:2008 [1], ACI 318- 14 [2] and fib Model Code for Concrete Structures 2010 [3]. The analysis also consists of methods published in technical literature. Calculations of shear strengths were made based...
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Debonding Size Estimation in Reinforced Concrete Beams Using Guided Wave-Based Method
PublicationThe following paper presents the results of the theoretical and experimental analysis of the influence of debonding size on guided wave propagation in reinforced concrete beams. The main aim of the paper is a development of a novel, baseline-free method for determining the total area of debonding between steel rebar embedded in a concrete cover on the basis of the average wave velocity or the time of flight. The correctness of...
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Laboratory fatigue assessment of large geocomposite-reinforced double-layered asphalt concrete beams
PublicationGeosynthetic reinforcement of asphalt layers has been used for several decades. Evaluation of the influence of these materials on pavement fatigue life is still ongoing, especially for new types of geocomposites. This paper presents the evaluation of fatigue performance of large asphalt concrete beams reinforced with a new type of composite in which square or hexagonal polypropylene stiff monolithic paving grid with integral junctions...
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Coda wave interferometry in monitoring the fracture process of concrete beams under bending test
PublicationEarly detection of damage is necessary for the safe and reliable use of civil engineering structures made of concrete. Recently, the identification of micro-cracks in concrete has become an area of growing interest, especially using wave-based techniques. In this paper, a non-destructive testing approach for the characterization of the fracture process was presented. Experimental tests were made on concrete beams subjected to mechanical...
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Thermal self-action effects for acoustic beams containing fronts in a Maxwell relaxing fluid
PublicationThis paper examines the thermal self-action of acoustic beams in a Maxwell relaxing fluid. This type of thermal self-action differs from that in a Newtonian fluid and behaves differently depending on a ratio of sound period and time of thermodynamic relaxation. The self-action which relates to sound beams containing shock fronts is also discussed. In addition, stationary and non-stationary types of self-action are considered.
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Conventional and advanced bending strength analysis of common and castellated, homogeneous and hybrid I-beams
PublicationAnaliza wytrzymałości na zginanie belek dwuteowych
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Numerical studies on size effects in concrete beams. Architecture Civil Engineering Environment ACEE
PublicationW artykule przedstawiony wyniki obliczeń efektów skali w belkach betonowych podczas zginania. Zastosowano model sprężysto-plastyczny z nielokalnym osłabieniem. Rozkład wytrzymałości na rozciąganie był stochastyczny - przestrzennie skorelowany. Belki były geometrycznie podobne. Wyniki porównano z modelem efektu skali Bazanta.
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Experimental and numerical investigations of size effects in reinforced concrete beams with steel or basalt bars.
PublicationW artykule przedstawiono wyniki obliczeń efektów skali w belkach betonowych zbrojonych prętami stalowymi i bazaltowymi podczas zginania. Zastosowano model sprężysto-plastyczny z nielokalnym osłabieniem. Rozkład wytrzymałości na rozciąganie był stochastyczny – przestrzennie skorelowany. Belki były geometrycznie podobne. Wyniki porównano z modelem efektu skali Bazanta
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Numerical investigations of size effects in notched and un-notched concrete beams under bending
PublicationW artykule przedstawiono wyniki numerycznej analizy efektów skali (efektu deterministycznego i stochastycznego) w belkach betonowych z nacięciem i bez nacięcia poddanych zginaniu z uwzględnieniem lokalizacji odkształceń. Obliczenia wykonano przy zastosowaniu metody elementów skończonych i sprężysto-plastycznego modelu z nielokalnym osłabieniem. Pokazano wpływ wielkości belek betonowych na ich nośność oraz rozkład lokalizacji odkształceń.
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Tagged images with LEGO bricks - Technic Beams
Open Research DataThe set contains images of LEGO bricks (from Technic Beams category). The images were prepared for training neural network for recognition and labeling of LEGO bricks. The images contain one brick each. The images were taken from different sides by handheld camera hovering over the bricks lying on a white, non reflective surface.
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Force transfer and stress distribution in short cantilever deep beams loaded throughout the depth with a various reinforcement
PublicationDeep beams used as the main reinforced concrete structural elements which taking over the load and stiffening construction are often found in high-rise buildings. The architecture of these buildings is sometimes sophisticated and varied, arouse the admiration of the majority of recipients, and thus causing an engineering challenge to correctly design the structural system and force transfer. In such structures is important to shape...
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Chained machine learning model for predicting load capacity and ductility of steel fiber–reinforced concrete beams
PublicationOne of the main issues associated with steel fiber–reinforced concrete (SFRC) beams is the ability to anticipate their flexural response. With a comprehensive grid search, several stacked models (i.e., chained, parallel) consisting of various machine learning (ML) algorithms and artificial neural networks (ANNs) were developed to predict the flexural response of SFRC beams. The flexural performance of SFRC beams under bending was...
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Sensitivity analysis of free torsional vibration frequencies of thin-walled laminated beams under axial load
PublicationThe paper addresses sensitivity analysis of free torsional vibration frequencies of thin-walled beams of bisymmetric open cross-section made of unidirectional fibre-reinforced laminate. The warping effect and the axial end load are taken into account. The consideration is based upon the classical theory of thin-walled beams of non-deformable cross-section. The first-order sensitivity variation of the frequencies is derived with...
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Composite Beams with glass and reinforced or prestressed concrete - early stage of a theorethical and experimental analysis of a shear zone
PublicationThe aim of this article is to present a forgoing preparation for a theoretical and experimental analysis of a shear zone of a composite beams with glass and reinforced or prestressed concrete. Authors present their current knowledge, achievements and predicted challenges in later stages of the research. Properties of component materials are presented in the context of compensating weaknesses of one material with strengths of the...
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Investigations on fracture in reinforced concrete beams in 3-point bending using continuous micro-CT scanning
PublicationThis study explores a fracture process in rectangular reinforced concrete (RC) beams subjected to quasi-static three-point bending. RC beams were short and long with included longitudinal reinforcement in the form of a steel or basalt bar. The ratio of the shear span to the effective depth was 1.5 and 0.75. The focus was on the load–deflection diagram and crack formation. Three-dimensional (3D) analyses of the size and distribution...
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FE analysis of a coupled energetic-statistical size effect in plain concrete beams with varying material properties.
PublicationThe numerical FE investigations of a coupled energetic-statistical size effect in unnotched concrete beams of similar geometry under quasi-static three point bending were performed within elasto-plasticity with non-local softening. The stochastic FE analyses were carried out with three different beam sizes. Deterministic calculations were performed with the uniform distribution of a uniaxial tensile strength. In statistical calculations...
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A new hyperbolic-polynomial higher-order elasticity theory for mechanics of thick FGM beams with imperfection in the material composition
PublicationA drawback to the material composition of thick functionally graded materials (FGM) beams is checked out in this research in conjunction with a novel hyperbolic‐polynomial higher‐order elasticity beam theory (HPET). The proposed beam model consists of a novel shape function for the distribution of shear stress deformation in the transverse coordinate. The beam theory also incorporates the stretching effect to present an indirect...
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SFEM Analysis of Beams with Scaled Lengths including Spatially Varying and Cross-Correlated Concrete Properties
PublicationThis paper presents the results obtained for plain concrete beams under four-point bending with spatially varying material properties. Beams of increasing length but constant depth were analyzed using the stochastic finite element method. Spatial fluctuation of a uniaxial tensile strength, fracture energy and elastic modulus was defined within cross-correlated random fields. The symmetrical Gauss probability distribution function...
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The vibration-based assessment of the influence of elevated temperature on the condition of concrete beams with pultruded GFRP reinforcement
PublicationConcrete beams reinforced with glass fiber reinforced polymer (GFRP) bars subjected to elevated temperature have been experimentally studied. The influence of high temperatures on GFRP-reinforced concrete beams condition has been check both, destructively and nondestructively. The nondestructive tests foresaw vibration-based tests to obtain the natural frequency values after exposure to varying temperatures. The vibration-based...
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Reference-free determination of debonding length in reinforced concrete beams using guided wave propagation
PublicationThis paper presents theoretical and experimental investigations of guided wave propagation in reinforced concrete beams, with pre-existing debonding between steel rebars and concrete blocks, for the purpose of damage detection. The primary aim of these investigations was a detailed analysis of the possible applications of wave propagation in single and multiple debonding detection in reinforced concrete structures and reference-free...
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Size effect in concrete beams under bending – influence of the boundary layer and the numerical description of cracks
PublicationIn the paper the size effect phenomenon in concrete is analysed. The results of numerical simulations of using FEM on geometrically similar un-notched and notched concrete beams under bending are presented. Concrete beams of four different sizes and five different notch heights under three-point bending test were simulated. In total 18 beams were analysed. Two approaches were used to describe cracks in concrete. First, eXtended...
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Three-point bending test of sandwich beams supporting the GFRP footbridge design process - validation
PublicationSome selected aspects concerning material and construction design issues for pedestrian footbridge made of GFRP composite materials are elaborated in this paper. The analysis is focused on validation tests, which are particularly important because of the advanced technology and materials that are used for this innovative bridge. The considered footbridge is a sandwich-type shell structure comprising of PET foam core and outer skins...
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Experimental study of shear strength and failure mechanisms in RC beams scaled along height or length
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Performance of the CMS Level-1 trigger during commissioning with cosmic ray muons and LHC beams
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Modelling and parameter identification of steel–concrete composite beams in 3D rigid finite element method
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Experimental and numerical assessment of size effect in geometrically similar slender concrete beams with basalt reinforcement
PublicationW artykule przedstawiono doświadczalne i numeryczne wyniki badań efektu skali w geometrycznie podobnych smukłych belkach betonowych ze zbrojeniem bazaltowym. Doświadczenia zostały symulowane stosując metodę elementów skończonych w oparciu o model sprężysto-plastyczny z degradacją sztywności i nielokalnym osłabieniem. Otrzymano dobrą zgodność wyników doświadczalnych z numerycznymi.
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Experimental Investigations of Fracture Process Using DIC in Plain and Reinforced Concrete Beams under Bending
PublicationThe fracture behaviour of concrete and reinforced concrete beams under quasi-static three-point bending was comprehensively investigated with experiments at laboratory scale. The eight various concrete mixes were tested. The influence of the shape, volume and size of aggregate particles and reinforcement on concrete fracture under bending was studied. Displacements on the surface of concrete beams were measured by means of the...
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FE-investigations on crack spacing in reinforced concrete beams within non-local continuum mechanics.
PublicationW artykule przedstawiono wyniki numerycznej analizy rozstawu rys w belkach żelbetowych przy zastosowaniu dwóch ciągłych modeli nielokalnych. Zbadano wpływ wielu różnych parametrów na rozstaw rys.
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Two - scale model for concrete beams subjected to three point bending - numerical analyses and experiments
PublicationArtykuł omawia dwu-skalowe podejście do betonu przy wykorzystaniu połączonych modeli. Metodę elementów skończonych zastosowano na poziomie makro. Na poziomie mikro zastosowano metodę elementów dyskretnych. Macierz sztywności wyznaczono na podstawie tensora naprężeń wyznaczonego w skali mikro. Wyniki numeryczne dw-skalowe porównano z wynikami dyskretnymi dla całego obszaru.
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Experimental study of shear strength and failure mechanisms in RC beams scaled along height or length
PublicationArtykuł omawia wyniki doświadczalne efektu skali w belkach żelbetowych bez zbrojenia pionowego. Belki żelbetowe były zeskałowane wzdłuż wysokości i długości. Zaobserwowane 3 różne mechanizmy zniszczenia w doświadczeniach. Wyniki efektu skali porównano z niektórymi wzorami analitycznymi z literatury.
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Tagged images with LEGO bricks - Technic Beams Special
Open Research DataThe set contains images of LEGO bricks (from Technic Beams Special category). The images were prepared for training neural network for recognition and labeling of LEGO bricks. The images contain one brick each. The images were taken from different sides by handheld camera hovering over the bricks lying on a white, non reflective surface.
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FE investigations of the effect of fluctuating local tensile strength on coupled energetic-statistical size effect in concrete beams
PublicationThe effect of fluctuating local tensile strength on a coupled energetic-statistical size effect in plain concrete beams under bending was numerically investigated. First, the influence of varying autocorrelation length of the random field describing a spatial variation of local tensile strength was studied. Next, the influence of the coefficient of variation of local tensile strength was analyzed. The numerical FE investigations...
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Non-Destructive Diagnostics of Concrete Beams Strengthened with Steel Plates Using Modal Analysis and Wavelet Transform
PublicationExternally bonded reinforcements are commonly and widely used in civil engineering objects made of concrete to increase the structure load capacity or to minimize the negative effects of long-term operation and possible defects. The quality of adhesive bonding between a strengthened structure and steel or composite elements is essential for effective reinforcement; therefore, there is a need for non-destructive diagnostics of adhesive...
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Experimental validation of the use of energy transfer ratio (ETR) for damage diagnosis of steel-concrete composite beams
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A TPC Detector for Studying Photo-nuclear Reactions at Astrophysical Energies with Gamma-ray Beams at ELI--NP
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