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Search results for: ELASTIC PIPE
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The Role of Molecular Structure in Monte Carlo Simulations of the Secondary Electron Yield and Backscattering Coefficient from Methacrylic Acid
PublicationIn this paper, we show the influence of the chemical structure of four different conformers on the secondary electron emission and backscattering of an electron beam from a gel of methacrylic acid. The conformers have different permanent dipole moments, which determines the cross sections for elastic collisions with electrons. The cross sections are used in Monte Carlo simulations of an electron beam, which enters the gel of methacrylic...
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Similarity Measures for Face Images: An Experimental Study
PublicationThis work describes experiments aimed at finding a straightforward but effective way of comparing face images.We discuss properties of the basic concepts, such as the Euclidean, cosine and correlation metrics, test the simplest version of elastic templates, and compare these solutions with distances based on texture descriptors (Local Ternary Patterns). The influence of selected image processing methods (e.g. bilateral ltering)...
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Geometrically nonlinear FEM analysis of 6-parameter resultant shell theory based on 2-D Cosserat constitutive model
PublicationWe develop the elastic constitutive law for the resultant statically and kinematically exact, nonlinear, 6-parameter shell theory. The Cosserat plane stress equations are integrated through-the- thickness under assumption of the Reissner-Mindlin kinematics. The resulting constitutive equations for stress resultant and couple resultants are expressed in terms of two micropolar constants: the micropolar modulus Gc and the micropolar...
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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...
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Numerical FDM modelling of wave propagation in concrete structure
PublicationThe article presents application of finite difference method to damage detection and its size evaluation in concrete structure by elastic wave propagation method. The simulations of wave propagation in concrete structure were performed for six different damage scenarios. Damages were modelled as areas with changed material properties. Investigation focused on the influence of damage size on the energy of wave reflection. Presented...
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Laminated plates and shells - first ply failure analysis within 6-parameter shell theory
PublicationThis work describes Tsai-Wu and Hashin criteria modifications, dictated by nonlinear 6-parameter shell theory with asymmetric strain measures and drilling rotation. The material law is based on standard orthotropic elastic constants for a non-polar continuum, under plane state of stress. First ply failure loads of cylindrical panel subjected to pressure and flat compressed plate are estimated by means of Finite Element Analysis....
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Application of the distributed transfer function method and the rigid finite element method for modelling of 2-D and 3-D systems
PublicationIn the paper application of the Distributed Transfer Function Method and the Rigid Finite Element Method for modelling of 2-D and 3-D systems is presented. In this method an elastic body is divided into 1-D distributed parameter elements (strips or prisms). The whole body (divided into strips or prism) is described by a set of coupled partial differential equations. Solving this equations in the state space form it is possible...
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Elastofibroma - Male, 58 - Tissue image [6070730010412831]
Open Research DataThis is the histopathological image of CONNECTIVE, SUBCUTANEOUS AND OTHER SOFT TISSUES tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Elastofibroma - Male, 58 - Tissue image [6070730010418871]
Open Research DataThis is the histopathological image of CONNECTIVE, SUBCUTANEOUS AND OTHER SOFT TISSUES tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Elastofibroma - Male, 58 - Tissue image [6070730010412761]
Open Research DataThis is the histopathological image of CONNECTIVE, SUBCUTANEOUS AND OTHER SOFT TISSUES tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Elastofibroma - Male, 58 - Tissue image [6070730010415851]
Open Research DataThis is the histopathological image of CONNECTIVE, SUBCUTANEOUS AND OTHER SOFT TISSUES tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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On the well posedness of static boundary value problem within the linear dilatational strain gradient elasticity
PublicationIn this paper, it is proven an existence and uniqueness theorem for weak solutions of the equilibrium problem for linear isotropic dilatational strain gradient elasticity. Considered elastic bodies have as deformation energy the classical one due to Lamé but augmented with an additive term that depends on the norm of the gradient of dilatation: only one extra second gradient elastic coefficient is introduced. The studied class...
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Vibro piles performance prediction using result of CPT
PublicationVibro piles belong to the group of full displacement piles with an expanded base, characterised by a very high load capacity, especially in non-cohesive soils. The problem is to adopt a reliable method for the determination of full load–settlement (Q–s) curve. A frequent difficulty is the determination of the load capacity limit based on the static load test because the course of the load–settlement curve is of a linear nature....
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Analysis of Crash Computation on a Basis of the Pronciple of Linear Momentum and Kinetic Energy
PublicationThe article shows the calculation of a vehicle crash with a fixed pile, modelled by the finite element method. There were compared during the crash simulations changes in kinetic energy, as well as – changes in linear momentum and its derivative, with respect to time. Calculations were made in the HyperWorks CAE software environment. The obtained results show influence of various body parts and devices of the deceleration on...
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Leakage detection and localisation in drinking water distributionnetworks by MultiRegional PCA
PublicationMonitoring is one of the most important steps in advanced control of complex dynamic systems. Precise information about systems behaviour, including faults indicating, enables for efficient control. The paper describes an approach to detection and localisation of pipe leakage in Drinking Water Distribution Systems (DWDS) representing complex and distributed dynamic system of large scale. Proposed MultiRegional Principal Component...
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Nuclear Co-generation: The Analysis of Technical Capabilities and Cost Estimates
PublicationThis paper presents a concept of the parallel connection of a nuclear power plant fitted to provide heat for district heating application, with the CHP and heat plants existing in the supply region, in this case with the heating systems of Wejherowo and Gdynia. Presented variant proposes to add heat to a nuclear power plant’s total output by supplying heat exchangers with the steam from bleeders of low pressure (LP) turbine stage...
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A higher order transversely deformable shell-type spectral finite element for dynamic analysis of isotropic structures
PublicationThis paper deals with certain aspects related to the dynamic behaviour of isotropic shell-like structures analysed by the use of a higher order transversely deformable shell-type spectral finite element newly formulated and the approach known as the Time-domain Spectral Finite Element Method (TD-SFEM). Although recently this spectral approach is reported in the literature as a very powerful numerical tool used to solve various...
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Modeling process of planning finished product sales volumes at industrial enterprises in modern economic conditions
PublicationThis article presents improving the existing system of planning finished products sales volumes. The influencing factors of the sales volumes in modern economic conditions have been determined: falling world oil prices, the reduction of pipe consumption in the domestic market, the global pandemic. The algorithm of planning finished products sales volumes has been constructed. Calculations based on the Holt forecasting method has...
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Investigation of rotational state-changing collisions of C2N− ions with helium
PublicationThe cross sections for rotational inelastic collisions between atoms and a molecular anion can be very large, if the anion has a dipole moment. This makes molecular anions very efficient in cooling atomic gases. We address rotational inelastic collisions of Helium atoms with the molecular anion C2N–. Here we present preliminary calculations of the potential energy surface.
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Detection of defects in PMMA beam using shear waves - numerical simulation and experiment
PublicationTest doświadczalny falami sprężystymi jest częścią systemu diagnostycznego belek. Autorzy badają pole przyspieszeń wywołane przepływem fal ultradźwiękowych i jego modyfikacje wynikające z wprowadzonych uszkodzeń belki. Artykuł porównuje wyniki eksperymentalne z symulacjami numerycznymi MES. The experimental test introduced in the paper is the part of the diagnostic system utilizing the elastic waves. The authors investigate the...
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On the use of uniaxial one-parameter damage laws for estimating fatigue life under multiaxial loading
PublicationThe goal of this paper is to evaluate the capabilities of different one-parameter fatigue laws to estimate crack initiation in notched components under multiaxial loading. Fatigue damage is accounted for through stress-based, strain-based, and energy-based approaches while the cyclic plasticity at the notch-controlled process zone is estimated using linear-elastic simulations. The results show that energy-based formulations established...
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Cross section calculations for electron scattering from platinum chemotherapeutic compounds
PublicationCross section for electron impact ionization of carboplatin, C6H12N2O4Pt, and oxaliplatin, C8H14N2O4Pt, have been calculated within binary-encounter-Bethe model for energies from the ionization threshold up to 5000 eV. Cross section for elastic electron scattering from carboplatin and oxaliplatin molecules have also been derived using independent atom method (IAM) and additivity rule for collision energies ranging from 50 eV to...
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Mechanical properties for preliminary design of structures made from PVC coated fabric
PublicationIn this paper, laboratory tests necessary for the identification of non-linear elastic immediate properties of the PVC coated polyester fabric (like AF 9032) are described. The material parameters are specified on the basis of the uniaxial tensile tests in the warp and weft directions as well as on the base of the biaxial tensile tests. For the identification process techniques based on the least squares method are used. The authors...
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Investigation of abdomen surface deformation due to life excitation: implications for implant selection and orientation in laparoscopic ventral hernia repair
PublicationVentral hernia is a common medical problem. Statistically there are around 10% recurrences of the sickness. The authors' former investigation proved edges of the hernia orifice displacements to be one of the factors causing recurrence. Thus, experimental investigation of the abdomen surface deformation due to some normal activities of people is studied.The extreme strains, their localization and directions are identified. The acquired...
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Design of septic tanks placed on cohesive soils
PublicationThe paper presents a short review of literature with regard to design and erection of the reinforced concrete and concrete tanks. The authors investigated the underground septic tank with of 10 m3 capacity placed on cohesive soils. The authors compared the values of internal forces for soils in drained and undrained conditions with different geotechnical parameters: loamy sand of liquidity index IL = 0.1 and IL = 0.7 and clay with...
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Acceleration waves in the nonlinear micromorphic continuum
PublicationWithin the framework of the nonlinear elastic theory of micromorphic continua we derive the conditions for propagation of acceleration waves. An acceleration wave, also called a wave of weak discontinuity of order two, can be treated as a propagating nonmaterial surface across which the second derivatives of the placement vector and micro-distortion tensor may undergo jump discontinuities. Here we obtain the acoustic tensor for...
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Comparison of anti-plane surface waves in strain-gradient materials and materials with surface stresses
PublicationHere we discuss the similarities and differences in anti-plane surface wave propagation in an elastic half-space within the framework of the theories of Gurtin–Murdoch surface elasticity and Toupin–Mindlin strain-gradient elasticity. The qualitative behaviour of the dispersion curves and the decay of the obtained solutions are quite similar. On the other hand, we show that the solutions relating to the surface elasticity model...
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On stress singularity near the tip of a crack with surface stresses
PublicationIn the framework of the simplified linear Gurtin–Murdoch surface elasticity we discuss a singularity of stresses and displacements in the vicinity of a mode III crack. We show that inhomogeneity in surface elastic properties may significantly affect the solution and to change the order of singularity. We also demonstrate that implicitly or explicitly assumed symmetry of the problem may also lead to changes in solutions. Considering...
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Zużycie ostrzy pił trakowych
Publicationkinematyka pilarek ramowych sprawia, że każde ostrze piły trakowej oddziela materiał o innym przekroju warstwy skrawanej. Odmienne warunki pracy poszczególnych ostrzy piły trakowej powodują, że ich zużycie jest zróżnicowane. Znajomość formy i rozkładu wartości zużycia kolejnych ostrzy w pile trakowej daje możliwość lepszego diagnozowania ich przydatność i do pracy.
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Water-Lubricated Sintered Bronze Journal Bearings—Theoretical and Experimental Research
PublicationWater lubricated bearings are used from many years in shipbuilding, hydro power and other industries because of their advantages such as: extensive serviceable life, low coefficient of friction, longevity of shaft sleeve, good abrasion resistance, low maintenance required, unit simplicity, no danger of pollution and low price. Various types of water lubricated sliding bearings have been tested at the Technical University of Gdansk...
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Torsional elasticity and energetics of F1-ATPase
PublicationFoF1-ATPase is a rotary motor protein synthesizing ATP from ADP driven by a cross-membrane proton gradient. The proton flow through the membrane-embedded Fo generates the rotary torque that drives the rotation of the asymmetric shaft of F1. Mechanical energy of the rotating shaft is used by the F1 catalytic subunit to synthesize ATP. It was suggested that elastic power transmission with transient storage of energy in some compliant...
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Assessment of Thermal Stresses in Asphalt Mixtures at Low Temperatures Using the Tensile Creep Test and the Bending Beam Creep Test
PublicationThermal stresses are leading factors that influence low-temperature cracking behavior of asphalt pavements. During winter, when the temperature drops to significantly low values, tensile thermal stresses develop as a result of pavement contraction. Creep test methods can be suitable for the assessment of low-temperature properties of asphalt mixtures. To evaluate the influence of creep test methods on the obtained low-temperature...
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New perspective on the in vivo use of cold stress dynamic thermography in integumental reconstruction with the use of skin-muscle flaps
PublicationAmong the problems encountered by plastic surgeons is the reconstruction of defects following tumors. One of the reconstructive options is TRAM flap. Despite that anatomy is well-explored, marginal flap necrosis may develop. To minimize complications imaging examinations was designed to determine the degree of flap perfusion. One of them is the thermographic examination.
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The experimental and numerical investigation of fracture behaviour in PMMA notched specimens under biaxial loading conditions – Tension with torsion
PublicationThis paper presents the results of experimental fracture test of flat PMMA specimens under biaxial loading condition tension with torsion (proportional). The specimens were made in two thicknesses: 5 and 15 mm and were weakened with V-type edge notches with different root radii: 0.5; 2 and 10 mm. Thanks to the ARAMIS 3D 4 M non-contact vision system, measurement of the elongation and twist angle were recorded. During experimental...
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Evaluation of thermal cracking probability for asphalt concretes with high percentage of RAP
PublicationThe paper presents determination of the probability of thermal cracking of asphalt mixtures with different reclaimed asphalt pavement (RAP) content on the basis of laboratory tests and analytical evaluation using thermal stress development method. Probability was evaluated taking into consideration: the type and gradation of the mixture and the quality and content of RAP. Thermal stresses were determined using two models: elastic and...
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On the material symmetry group for micromorphic media with applications to granular materials
PublicationWithin the framework of the theory of nonlinear elastic micromorphic continua we introduce the new definition of the local material symmetry group. The group consists of ordered triples of second- and third-order tensors describing such changes of a reference placement that cannot be recognized with any experiment. Using the definition we characterize the micromorphic isotropic media, micromorphic fluids, solids and special intermediate...
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Vibration of the bridge under moving singular loads - theoretical formulation and numerical solution
PublicationThe paper presents the results of the numerical analysis of a simple vehicle passing over a simply supported bridge span. The bridge is modelled by a Euler-Bernoulli beam. The vehicle is modelled as a linear, visco-elastic oscillator, moving at a constant speed. The system is described by a set of differential equations of motion and solved numerically using the Runge-Kutta algorithm. The results are compared with the solution...
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Smart Virtual Product Development (SVPD) System to Support Product Inspection Planning in Industry 4.0
PublicationThis paper presents the idea of supporting product inspection planning process during the early stages of product life cycle for the experts working on product development. Aim of this research is to assist a collaborative product development process by using Smart Virtual Product Development (SVPD) system, which is based on Set of Experience Knowledge Structure (SOEKS) and Decisional DNA (DDNA). The proposed system is developed...
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Influence of high temperature air-steam mixture application on time wood drying process
PublicationThe results of influence gas-steam mixture drying process on time wood drying process are presented. Wood species, namely oak (Quercus L.), beech (Fagus L.), pine (Pinus L.) and spruce (Picea K.) from the northern part of Pomerania region in Poland, were subject of air-steam mixture drying process. Main focus of those tests was to shorten the time of drying process and afterward to check properties of wood.
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Turbulence model evaluation for numerical modelling of turbulent flow and heat transfer of nanofluids
PublicationIn this work, Nusselt number and friction factor are calculated numerically for turbulent pipe flow (Reynolds number between 6000 and 12000) with constant heat flux boundary condition using nanofluids. The nanofluid is modelled with the single-phase approach and the simulation results are compared with experimental data. Ethylene glycol and water, 60:40 EG/W mass ratio, as base fluid and SiO2 nanoparticles are used as nanofluid...
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A numerical analysis of the thermal effects in the jet impingement stagnation zone
PublicationMost of the flows occurring in the engineering systems are turbulent and their accurate numerical analysis is still challenging, especially when combined with the heat transfer. One of the methods of heat transfer enhancement is utilization of the turbulent impinging jets, which were recently applied also in the heat exchangers. Their positive impact on the heat transfer performance was proven, but many questions related to its...
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Urinary Tract Infections of Escherichia coli Strains of Chaperone-Usher System
PublicationZakażenia dróg moczowych stanowią bardzo poważny problem zdrowotny i ekonomiczny dotyczący milionów ludzi, każdego roku na całym świecie. Najbardziej rozpowszechnionym czynnikiem etiologicznym tego typu infekcji bakteryjnych, obejmujących górne i dolne drogi moczowe, są szczepy E. coli, reprezentujące około 80% przypadków. Uropatogenne szczepy E. coli produkują kilka czynników urowirulentncyh, które można podzielić na dwa główne...
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FEM simulations applied to the failure analysis of RC structure under the influence of municipal sewage pressure
PublicationThe paper discusses a failure mechanism of reinforced concrete (RC) structure with steel cover that failed under the influence of municipal sewage pressure. To explain the reasons of failure, in-situ measurements, laboratory experiments and comprehensive Finite Element Method (FEM) computations were performed. Non-destructive in-situ scanning tests were carried out to determine quantity and cover thickness of embedded reinforcement...
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Degradation of polyurethanes in Compost Under Natural Conditions
PublicationThe estimation of degradibility of different polyurethanes under natural weather depending conditions in compost pile was the subject of the studies. The incubation of polymer samples took place for a period up to 24 months. The characteristic parameters of the compost: temperature, pH, moisture content, and activity of dehydrogenasis were monitored and their influence on degradation of polyuiretahnes was discussed. The compostability...
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Diagnostic Models and Estimators for LDI in Transmission Pipelines
PublicationThis article considers and compares four analytical models of the pipeline flow process for leak detection and location tasks. The synthesis of these models is briefly outlined. Next, the methodology for generating data and diagnosing pipes is described, as well as experimental settings, assumptions and implemented scenarios. Finally, the quality of model-based diagnostic estimators has been evaluated for their bias, standard deviations...
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Analysis of sloping brace stiffness influence on stability and load bearing capacity of a truss
PublicationThe paper is focused on the numerical study of stability and load bearing capacity of a truss with side elastic braces. The structure is made in reality. The rotational and sliding brace stiffnesses were taken into account. Linear buckling analysis and non-linear static analysis with geometric and material nonlinearity were performed for the beam and shell model of the truss with respect to the angle of sloping braces. As a result...
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Effect of underwater local cavity welding method conditions on diffusible hydrogen content in deposited metal
PublicationOne of the methods with great potential for applications in underwater repairs is local cavity welding. In local cavity method, cooling conditions and diffusible hydrogen amount in weld metal are nearly the same as those existed during welding in the air. This paper presents the results of literature survey and preliminary tests of the effect of local cavity welding conditions on diffusible hydrogen amount in a deposited metal....
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Ultrasonic diagnostics of concrete T-beams used in bridge structures
PublicationThis paper describes a method of ultrasonic diagnostics used for prefabricated concrete elements. The studies are focused on the applicability of nondestructive techniques based on impulse and wave packet induced elastic waves for the condition assessment of T-shaped bridge beams. Experimental tests were performed for the prestressed beam used for the superstructure of the viaduct on A1 highway near Toruń. In addition numerical...
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Stability of an imperfect truss loaded by wind
PublicationThe present paper is devoted to the numerical research of stability of a truss loaded by wind and stiffened by elastic supports located at the top chord. The lateral braces or lateral and torsional braces were taken into account. In this paper, the linear buckling analysis re- sults for the beam and shell model were presented. Two different shapes of initial geometric imperfections were considered in the non-linear static analysis...
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Detection of debonding in reinforced concrete beams using ultrasonic transmission tomography and hybrid ray tracing technique
PublicationThis paper concerns inspection of reinforced concrete elements, with particular emphasis on assessing the quality of the adhesive connection between steel and concrete. A novel theoretical model was developed to determine the paths of transmitted, refracted and reflected elastic waves as well as a creeping wave propagated along the inclusion surface. Imaging the internal structure of tested beams was based on wave propagation measurements...