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Does Nitrogen Fertilization Affect the Secondary Structures of Gliadin Proteins in Hypoallergenic Wheat?
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A review of stability problems of thin-walled structures developed at Gdańsk University of Technology
PublicationW pracy podano przegląd problemów stateczności konstrukcji cienkościennych, które były przedmiotem badań na Politechnice Gdańskiej. Przedstawiono bibliografię obejmującą 75 prace podzielone na trzy grupy tematyczne: stateczność prętów i łuków, pokrytyczne zachowanie się elemntów oraz optymalne projektowanie i analizę wrażliwości.
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Some remarks about numerical stability in nonlinear dynamics on the basic of truss structures.
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Eficient multimode mixed time-frequency domain analysis and optimization of waveguide structures.
PublicationW pracy przedstawiona jest pełnofalowa analiza i optymalizacja struktur falowodowych o zadanej topologii. Nieciągłości falowodowe analizowane są z wykorzystaniem metody FDTD-IBC oraz scharakteryzowane uogólnioną macierzą rozproszenia. Efektywność metody zilustrowana jest na przykładzie filtru falowodowego siódmego rzędu.
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Eficient multimode mixed time-frequency domain analysis and optimization of waveguide structures.
PublicationW pracy przedstawiona jest pełnofalowa analiza i optymalizacja struktur falowodowych o zadanej topologii. Nieciągłości falowodowe analizowane są z wykorzystaniem metody FDTD-IBC oraz scharakteryzowane uogólnioną macierzą rozproszenia. Efektywność metody zilustrowana jest na przykładzie filtru falowodowego siódmego rzędu.
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Production structures and strategies supporting lean parts manufacturing: an industrial case study.
PublicationPrzedstawiono model sformalizowanego opisu wzorców możliwości wytwarzania zróżnicowanego spektrum przedmiotów oraz analizy podobieństwa ich procesów technologicznych, dla kształtowania struktur przestrzennych systemów typu gniazdowego, z uwzględnieniem paradygmatu oszczędnej produkcji. Zaproponowano algorytm grupowania przedmiotów wg określonych, w postaci ciągów znakowych, sekwencji operacji procesu technologicznego oraz kryterium...
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High-Efficacy Global Optimization of Antenna Structures by Means of Simplex-Based Predictors
PublicationDesign of modern antenna systems has become highly dependent on computational tools, especially full-wave electromagnetic (EM) simulation models. EM analysis is capable of yielding accurate representation of antenna characteristics at the expense of considerable evaluation time. Consequently, execution of simulation-driven design procedures (optimization, statistical analysis, multi-criterial design) is severely hindered by the...
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In-Reactor Polypropylene Functionalization─The Influence of Catalyst Structures and Reaction Conditions on the Catalytic Performance
PublicationTo unravel the relationship between silylene-bridged metallocene catalyst structures and polymerization conditions and their effect on the performance in in-reactor functionalization of polypropylene, the behaviors of rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2/MMAO, rac-Me2Si(Ind)2ZrCl2, rac-Me2Si(2-Me-4-Ph-Ind)2HfCl2, and rac-Me2Si(Ind)2HfCl2 in propylene/aluminum alkyl-passivated 10-undecen-1-ol copolymerization were compared. Kinetic analysis...
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Cyclic behaviour modelling of additively manufactured Ti-6Al-4V lattice structures
PublicationThe present work is concerned with the numerical modelling of the cyclic behaviour of Ti-6Al-4V lattice structures. In the study, diamond structures of titanium alloy produced by the additive laser powder bed fusion (LPBF) method with different degrees of relative density were used. Realistic geometric models of the studied mesostructures were generated using computed microtomography, taking into account the imperfections of the...
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Baseline-free debonding detection in reinforced concrete structures by elastic wave propagation
PublicationThe article presents the results of the numerical and experimental analysis concerning wave propagation in reinforced concrete (RC) beams with various extent of debonding between the steel rod and concrete cover. The main aim of the paper was to consider the unsolved research gaps, which considerably limit the application of wave-based methods in practice. The propagation of the flexural wave modes excited and registered on the...
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Low-strain sensor based on the flexible boron-doped diamond-polymer structures
PublicationA free-standing high boron-doped diamond nanosheet (BDDNS) has been fabricated for the development of a flexible BDDNS strain senor. High boron-doped diamond was initially grown on a tantalum substrate in a microwave plasma-assisted chemical vapor deposition method, and was then transferred to a Kapton polymer substrate to fabricate the flexible BDDNS/Kapton device. Before performing the transfer process, the thin BDDNS’s morphology...
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Accelerated Parameter Tuning of Antenna Structures by Means of Response Features and Principal Directions
PublicationPopularity of numerical optimization has been steadily on the rise in the design of modern antenna systems. Resorting to mathematically rigorous parameter tuning methods is a matter of practical necessity as interactive techniques (e.g., parameter sweeping) are no longer adequate when handling several performance figures over multi-dimensional parameter spaces. The most common design scenarios involve local tuning since decent...
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The new diphosphanylphosphido complexes of tungsten(VI) and molybdenum(VI). Their synthesis, structures and properties
PublicationWe report on the reactivity of R2P–P(Li)–PR’2 (R = tBu, iPr, R’ = NEt2, iPr) towards diimido complexes [(dippN)2MCl2·dme] (M = Mo, W and dipp = 2,6-iPr2C6H3). A series of new complexes with diphosphanylphosphido ligands R2P–P–PR’2 were isolated. The solid-state structures of [(dippN)2M(Cl)(1,2-η-iPr2P–P– PiPr2)] (2Mo and 2W) and [(dippN)2M(Cl){1,2-η-tBu2P–P–P(NEt2)2}] (3Mo and 3W) were established by single-crystal X-ray diffraction...
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Spectral Methods for Modelling of Wave Propagation in Structures in Terms of Damage Detection—A Review
PublicationModern methods of detection and identification of structural damage direct the activities of scientific groups towards the improvement of diagnostic methods using for example the phenomenon of mechanical wave propagation. Damage detection methods that use mechanical wave propagation in structural components are extremely effective. Many different numerical approaches are used to model this phenomenon, but, due to their universal...
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Grabe J.:Recommendations of the "Committee for Waterfront Structures Harbours and Waterways" EAU 2012
PublicationRecenzja - Grabe J.: Recommendations of the "Committee for Waterfront Structures Harbours and Waterways" EAU 2012. Ernst & Sohn, Berlin 2015
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Minimization of vibrations during milling of flexible structures using mechatronic design techniques
PublicationThe paper presents an innovative effective method of minimizing vibrations during milling of flexible structures, using a new vibration suppression method based on a workpiece holder with adjustable support stiffness. The proposed method is rooted in mechatronic design techniques, which can become a standard procedure for optimizing the milling process.
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Recovering Sound Produced by Wind Turbine Structures Employing Video Motion Magnification
PublicationThe recordings were made with a fast video camera and with a microphone. Using fast cameras allowed for observation of the micro vibrations of the object structure. Motion-magnified video recordings of wind turbines on a wind farm were made for the purpose of building a damage prediction system. An idea was to use video to recover sound & vibrations in order to obtain a contactless diagnostic method for wind turbines. The recovered signals...
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Proceedings of the fib Symposium 2019: Concrete - Innovations in Materials, Design and Structures 2019
PublicationDesigning a concrete mix is a process of synthesizing many components, it is not a simple process and requires extensive technical knowledge. The design process itself focuses on obtaining the required strength of concrete. Very often designing a concrete mix takes into account the need to maintain the proper water-demand and frost-resistance features. The parameters that influence the concrete class most significantly are the...
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Modeling protein structures with the coarse-grained UNRES force field in the CASP14 experiment
PublicationThe UNited RESidue (UNRES) force field was tested in the 14th Community Wide Experiment on the Critical Assessment of Techniques for Protein Structure Prediction (CASP14), in which larger oligomeric and multimeric targets were present compared to previous editions. Three prediction modes were tested (i) ab initio (the UNRES group), (ii) contact-assisted (the UNRES- contact group), and (iii) template-assisted (the UNRES-template...
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Accelerated Re-Design of Antenna Structures Using Sensitivity-Based Inverse Surrogates
PublicationThe paper proposes a novel framework for accelerated re-design (dimension scaling) of antenna structures using inverse surrogates. The major contribution of the work is a sensitivity-based model identification procedure, which permits a significant reduction of the number of reference designs required to render the surrogate. Rigorous formulation of the approach is supplemented by its comprehensive numerical validation using a...
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Kriging metamodels and design re‐utilization for fast parameter tuning of antenna structures
PublicationThe paper addresses the problem of computationally efficient electromagnetic (EM)‐driven design closure of antenna structures. The foundations of the presented approach are fast kriging interpolation metamodels, utilized for two purposes: (a) producing a good starting point for further parameter tuning, and (b) yielding a reasonable Jacobian matrix estimate to jump‐start the optimization procedure. The models are rendered using...
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Low-Cost Data-Driven Surrogate Modeling of Antenna Structures by Constrained Sampling
PublicationFull-wave electromagnetic (EM) analysis has become one of the major design tools for contemporary antenna structures. Although reliable, it is computationally expensive which makes automated simulation-driven antenna design (e.g., parametric optimization) difficult. This difficulty can be alleviated by utilization of fast and accurate replacement models (surrogates). Unfortunately, conventional data-driven modeling of antennas...
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The Revitalization Processes of the Port Structures in Gdynia and Gdansk on the Background of Contemporary Port Changes
PublicationTransformations of the port facilities against the modernization of the port structures are present in many city-port centers since more than 50 years. The modernization taking place in the ports located in Gdynia-Gdansk mainly concerns communication availability and adapted to the multimodal technology of transport and transshipment. Developing specialized tech-terminals serving a specific type of load, causes development of the...
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Particle Shape Effect on Macroscopic Behaviour of Underground Structures: Numerical and Experimental Study
PublicationThe mechanical performance of underground flexible structures such as buried pipes or culverts made of plastics depend not only on the properties of the structure, but also the material surrounding it. Flexible drains can deflect by 30% with the joints staying tight, or even invert. Large deformations of the structure are difficult to model in the framework of Finite Element Method, but straightforward in Discrete Element Methods....
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Destruction of shell structures under the dynamic load on the human skull trauma basis
PublicationThe main aim of this work is to investigate patterns of potential orbital bone fractures due to mechanical injuries. The solution of the main problem is followed by analysis of several testing examples having straight correlation with civil engineering structures, in which materials of wide range of stiffness are applied. To solve the main problem, the three-dimensional finite element method (FEM) model of the orbital region has...
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ECOLOGY OR ECONOMICS? THE ASPECT DETERMINING THE USE OF DISPLACEMENT PILES FOR THE FOUNDATIONS OF BRIDGE STRUCTURES
PublicationW ostatnich latach rzadko wykonuje się pale wiercone o bardzo dużych średnicach ze względu na: wymagany sprzęt, transport wydobytego urobku gruntowego, duże ilości stali zbrojeniowej. Konstrukcje inżynierskie na autostradzie A-1, na drodze ekspresowej S-7 i Obwodnicy Południowej Gdańska posadowiono na palach prefabrykowanych. Fundamenty największych mostów na autostradzie A-1 zbudowano na palach Vibro i Franki. W artykule zwrócono...
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Investigations of vortex structures in granular materials under earth pressure conditions by DEM
PublicationW artykule pokazano rozwój wirów na poziomie ziarna materiału granulowanego podczas parcia pasywnego piasku na sztywną ściankę przemieszczającą się poziomo. Obliczenia wykonano stosując metodę DEM. Przyjęto 3 różne sposoby wyznaczenia wirów i ich czestotliwości.
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DEFORMATIONS OF INNOVATIVE COLD-FORMED GEB SECTIONS
PublicationPermanent urban growth of the world of today world implies demanding challenges for the steel construction industry. Nowadays, one of the most important issues is the cost optimization of steel structures. Since the weight of building materials is a major component of the total cost, engineers and designers try to reduce structural weight, without compromising durability and sustainability of a steel structure. Therefore, light...
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Cavitation erosion degradation of Belzona® coatings
PublicationIn hydrocarbon and maritime industry there is a constant need of materials and coatings withstanding severe conditions. One of adverse phenomena present there is cavitation erosion. The paper presents evaluation of cavitation resistance of three different steel coatings. Belzona 2141 (ACR-Fluid Elastormer), 1321 (Ceramic S-Steal) and 5831 (ST-Barrier) were deployed on P110 steel and subjected to ultrasound cavitation in distilled...
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Machined Surface Roughness Including Cutter Displacements in Milling of Hardened Teel
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Wpływ mikrostruktury stali o podwyższonej wytrzymałości na niszczenie wodorowe = Influence o higher strength steel microstructure on hydrogen destruction
PublicationW artykule przedstawiono niszczenie wodorowe stali 18G2A i jej symulowanej strefy wpływu ciepła (SWC). Jako parametry niszczenia wodorowego wybrano względne wartości energii zniszczenia, wydłużenia, przewężenia i wytrzymałości na rozciąganie. Parametry te wyznaczono w próbie odkształcania z małą prędkością na próbkach okrągłych gładkich. Stwierdzono, że stal 18G2A w środowisku kwaśnym podczas polaryzacji katodowej jest bardziej...
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Simultaneous impedance and volumetric studies and additionally potentiodynamic polarization measurements of molasses as a carbon steel corrosion inhibitor in 1M hydrochloric acid solution
PublicationThe inhibition effect of molasses on the corrosion of low carbon steel in 1M hydrochloric acid solution was investigated by volumetric and electrochemical measurements. Potentiodynamic polarization and dynamic electrochemical impedance spectroscopy (DEIS) results were obtained and compared with to those, obtained with the hydrogen evolution technique. All results indicate that molasses functioned as a good inhibitor in 1M hydrochloric...
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Atomic force microscopy based approach to local impedance measurements of grain interiors and grain boundaries of sensitized AISI 304 stainless steel
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Studies of the mechanism of metal metal dusting of 10CrMo9-10 steel after 10 years of operation in trhe semi-regenerative catalytic reformer
PublicationThe study showed that metal dusting mechanism of 10CrMo9-10 steel operated in industrial environment differs from models developed in laboratories. Significant differences lie in the fact that the models developed in laboratories only assume the formation of metastable carbide M3C, while studies have shown that the formation of M3C carbides is associated with the transformation of primary carbides and in the next stage is preceded...
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Seismic damage diagnosis in adjacent steel and RC MRFs considering pounding effects through improved wavelet-based damage-sensitive feature
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Seismic damage diagnosis in adjacent steel and RC MRFs considering pounding effects through improved wavelet-based damage-sensitive feature
PublicationThis paper aims to propose complex Morlet (cmorfb-fc) wavelet-based refined damage-sensitive feature (rDSF) as a new and more precise damage indicator to diagnose seismic damages in adjacent steel and Reinforced Concrete (RC) Moment Resisting Frames (MRFs) assuming pounding conditions using acceleration responses. The considered structures include 6- and 9-story steel and 4- and 8-story RC benchmark...
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Atomic force microscopy based approach to local impedance measurements of grain interiors and grain boundaries of sensitized AISI 304 stanless steel
PublicationPraca prezentuje wyniki badań uzyskane z pomiarów techniką lokalnej spektroskopii impedancyjnej (LIS) wykonanych w trybie kontaktowym mikroskopii sił atomowych (AFM), które zostały przeprowadzone w lokalnych obszarach powierzchni ziarna austenitu i na granicy ziarna austenitu wysokostopowej stali austenitycznej AISI 304 poddanej procesowi uczulania oraz na próbkach odniesienia nie poddanych obróbce cieplnej.Badania LIS-AFM były...
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The Influence of the Application of EP Additive in the Minimum Quantity Cooling Lubrication Method on the Tool Wear and Surface Roughness in the Process of Turning 316L Steel
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Experimental investigation on welding of 2.25 Cr-1.0 Mo steel with regulated metal deposition and GMAW technique incorporating metal-cored wires
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Machine learning-based prediction of residual drift and seismic risk assessment of steel moment-resisting frames considering soil-structure interaction
PublicationNowadays, due to improvements in seismic codes and computational devices, retrofitting buildings is an important topic, in which, permanent deformation of buildings, known as Residual Interstory Drift Ratio (RIDR), plays a crucial role. To provide an accurate yet reliable prediction model, 32 improved Machine Learning (ML) algorithms were considered using the Python software to investigate the best method for estimating Maximum...
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"Raport z wstępnych badań własności stali trudnościeralnej 460HB",. ang "Report on preliminary tests of the properties of wear-resistant steel 460HB"
PublicationMikrostrukturę badanej stali trudnościeralnej 460HB stanowi drobnoziarnisty martenzyt odpuszczony, który jest właściwy dla stali konstrukcyjnych niskowęglowych, niskostopowych ulepszonych cieplnie. W przypadku blach grubych, do których zalicza się badana stal, struktura może ulec zaburzeniu, jeżeli w hutniczym procesie wytwórczym wystąpiła niejednorodność odkształcenia plastycznego i w konsekwencji tworzenie się pasm segregacyjnych,...
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Seismic damage diagnosis in adjacent steel and RC MRFs considering pounding effects through improved wavelet-based damage-sensitive feature
PublicationThis paper aims to propose complex Morlet (cmorfb-fc) wavelet-based refined damage-sensitive feature (rDSF) as a new and more precise damage indicator to diagnose seismic damages in adjacent steel and Reinforced Concrete (RC) Moment Resisting Frames (MRFs) assuming pounding conditions using acceleration responses. The considered structures include 6- and 9-story steel and 4- and 8-story RC benchmark MRFs that are assumed to have...
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Comparative study on fracture evolution in steel fibre and bar reinforced concrete beams using acoustic emission and digital image correlation techniques
PublicationIn recent decades, the demand for sustainable construction practices has increased, but raw materials such as reinforcing steel remain scarce. Therefore, steel fibres have emerged as a popular and sustainable choice in the construction industry, offering a cost-effective alternative to traditional steel bar reinforcement for both flatwork and elevated structures. The purpose of this study is therefore to compare the performance...
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Multi-response optimization on the effect of wet and eco-friendly cryogenic turning of D2 steel using Taguchi-based grey relational analysis
PublicationMaterial removal processes, including turning and milling, are still commonly used operations for manufacturing most of mechanical components in modern industry. Apart from the cutting parameters, the cooling method has the great impact on the technological efects and, above all, on the environmental friendliness of production. In this study, multi-response optimization on the efect of wet and cryogenic machining is performed during...
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Microcrack monitoring and fracture evolution of polyolefin and steel fibre concrete beams using integrated acoustic emission and digital image correlation techniques
PublicationThe use of polymer and steel fibres in plain concrete appears to be an excellent solution for limiting crack propagation and improving the post-ductility performance of concrete structures. Based on this premise, this study investigated the fracture evolution of polyolefin fibre-reinforced concrete (PFRC) and steel fibre-reinforced concrete (SFRC) specimens through the integrated application of two diagnostic techniques, acoustic...
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The effect of numerical 2D and 3D FEM element modelling on strain and stress distributions at laser weld notches in steel sandwich type panels
PublicationLike other means of transport, merchant ships face the problem of increasing requirements concerning the environment protection, which, among other issues, implies the reduction of fuel consumption by the ship. Here, the conventional approach which consists in making use of higher strength steels to decrease the mass of the ship hull can be complemented by the use of new steel structures of sandwich panel type. However, the lack...
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Laser Welding of UNS S33207 Hyper-Duplex Stainless Steel to 6061 Aluminum Alloy Using High Entropy Alloy as a Filler Material
PublicationThe high entropy alloy (HEA) filler used during the fabrication method determines the reliability of HEAs for steel-aluminum dissimilar alloy configuration. HEAs have a direct impact on the formation of intermetallic compounds (IMC) formed by the interaction of iron (Fe) and aluminum (Al), and influence the size of the joint’s interaction zone. A novel welding process for Fe-Al alloy joints was developed to prevent the development...
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Detection and Imaging of Debonding in Adhesive Joints of Concrete Beams Strengthened with Steel Plates Using Guided Waves and Weighted Root Mean Square
PublicationStrengthening of engineering structures is an important issue, especially for elements subjected to variable loads. In the case of concrete beams or slabs, one of the most popular approaches assumes mounting an external reinforcement in the form of steel or composite elements by structural adhesives. A significant disadvantage of adhesive joints is the lack of access to the adhesive film for visual condition assessment, thus, there...
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ENVIRONMENTAL DEGRADATION OF DISSIMILAR AUSTENITIC 316L AND DUPLEX 2205 STAINLESS STEELS WELDED JOINTS
PublicationThe paper describes structure and properties of dissimilar stainless steels welded joints between duplex 2205 and austenitic 316L steels. Investigations were focused on environmentally assisted cracking of welded joints. The susceptibility to stress corrosion cracking (SCC) and hydrogen embrittlement was determined in slow strain rate tests (SSRT) with the strain rate of 2.2 × 10–6 s–1. Chloride-inducted SCC was determined in the...
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OCENA WŁAŚCIWOŚCI STALI STOSOWANEJ W STARYCH OBIEKTACH KOLEJOWYCH
PublicationThe scope of the paper is to give an introduction to the assessment subject matter of steel properties used in old railway bridges. The mechanical and chemical properties of construction steel extracted from old steel bridges are generally investigated by tensile tests, impact tests through the Charpy pendulum impact V-notch, and an optical emission spectrometer. Besides descriptions of the tests, the chosen chemical and mechanical...