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Wyniki wyszukiwania dla: STEEL WELDABILITY, COLD CRACKING
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Underwater Welding of Duplex Stainless Steel
PublikacjaThe present work was conducted to assess the weldability of duplex stainless steel at underwater conditions. Interest of underwater welding of this steel grade is connected with necessity of preparing welding repair technologies for subsea pipelines widely used in offshore oil and gas industry. The GMA local cavity welding method was used in the investigations. Welded beads were performed underwater at 0.5 m depth and in the air....
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DEFORMATIONS OF INNOVATIVE COLD-FORMED GEB SECTIONS
PublikacjaPermanent 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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The Application of Cluster Analysis in the Assessment of the Weldability of Unalloyed Steels
PublikacjaNon-alloy steels constitute a large group of steels characterised by diversified chemical composition, structural morphology and a wide range of mechanical properties (determining weldability). The paper presents results of multidimensional analyses (based on cluster analysis) of 110 selected unalloyed steel grades. Properties adopted as diagnostic features included the chemical composition, mechanical properties (yield point)...
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ENVIRONMENTAL DEGRADATION OF DISSIMILAR AUSTENITIC 316L AND DUPLEX 2205 STAINLESS STEELS WELDED JOINTS
PublikacjaThe 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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Assessment of crack resistance of ship steels according to SEP 1390 standard
PublikacjaThe aim of the study was to evaluate the weldability of E36 nd NVE-36 steels by bending test according to SEP 1390. In the case of the specimen from E36 steel 9 external cracks were found, 5 of which were stopped in the fusion line and 4 in heat affected zone. In the case of the specimen from NVE-36 steel 8 external cracks were found, 4 of which were stopped in the fusion line and 4 in heat affected zone. Results of bending test...
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Effect of shielded electrode wet welding conditions on diffusible hydrogen content in deposited metal
PublikacjaWet welding is the most popular method of joining in water enviroment. During underwater welding, the weldability of steel is limited by the higher cooling rates and hydrogen content in weld metal. Article presents results of preliminary tests on the effects of wet welding conditions on diffusible hydrogen amount. Seven parameters were optimized using a Plackett-Burman plan to get the most relevant variables. These parameters were:...
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Deformations of the steel schell of a vertical cylindrical tank caused by underpressure
PublikacjaUnderpressure in a tank with a fixed roof may arise in the final stage of its construction as well as during its usage. This article presents stages of deformations of the tank shell and their development from the occurrence of the first deformation to either removal of the causes of underpressure or cracking of the steel shell.
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Thin-walled cross section shape influence on steel member resistance.
PublikacjaThis work describes why trending thin-walled technology is achieving popularity in steel construction sector. A purpose of this article is to present the influence of the cold-formed element cross-section shape on an axial compression and a bending moment resistance. The authors have considered four different shapes assuming constant section area and thickness. Calculations were based on three different steel grades taking into...
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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
PublikacjaThe 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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Hydrogen induced degradation of structural steel exposed to the technical liquid hydrocarbons
PublikacjaSusceptibility of the differently heat treated 26H2MF steel to stress corrosion cracking has been evaluated in the constant strain rate tension tests done at the strain rate 10-6s-1 and in the constant load tests done at the 0,98 of fracture load. The boiler fuel and the aged mineral oil at 135C and 80C respectively, have been used as the aggressive environments.
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Corrosion and Cavitation Resistances of Low Alloy Steel After Frictional-Mechanical Treatment
PublikacjaPaper presents the results of the studies of wear, corrosion and cavitation resistances of the S355J2 low alloy medium carbon steel subjected to surface modification by friction-mechanical treatment, as tested in sea water simulated solution. To evaluate the effect of the surface treatment, the comparative studies of the corrosive properties of the steel before and after treatment have been considered. The treatment due to a severe...
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The validation process of truss model with joint eccentricities
PublikacjaNowadays, due to the technological reasons in modern lightweight steel trusses, fabricated from cold-formed sections, positive eccentricities appear in the truss nodes, to induce additional forces truss chords. In order to account for the real load-carrying capacity of truss node area the steel structure research was conducted in scale 1:1. As a result of experimental research, the forms of deformation and strains of the walls...
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Effect of microstructure on mechanical properties and corrosion resistance of 2205 duplex stainless steel
PublikacjaThis paper presents results of the research on impact of microstructure of austenitic-ferritic steel of duplex type on its mechanical properties and susceptibility to stress corrosion cracking. As showed, improper processing technologies more and more often used in shipbuilding industry for plates and other half-finished products made of duplex steel may cause significant lowering their properties, which frequently makes their...
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Application of galvanodynamic impedance spectroscopy for studying passive film cracking under mechanical strain
PublikacjaThe paper reports the results of simultaneous mechanical and electrochemical investigations on austenitic (18/8) stainless steel in a 2 % solution of sulphuric acid. The measurements were performed using Galvanodynamic Electrochemical Impedance Spectroscopy (GDEIS). Electrochemical analysis of mechanical passive layer cracking and repassivation conditions during a tensile test was carried out. Application of this methodology allowed...
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Wet H2S corrosion and degradation of pipeline in amine regeneration system
PublikacjaThe paper presents the results of NDT examinations, metallographic tests and risk assessment of degradation related to corrosion of amine regeneration unit in a desulphurisation system. Intensive corrosion resulting from acid gases environment upon water condensation causes perforation of the pipeline. Detailed analysis reveals cracking related to the mechanism of wet H2S. Hydrogen penetration, resulting from the wet H2S process,...
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Preliminary study of linear viscoelasticity limits of cold recycled mixtures determined in Simple Performance Tester (SPT)
PublikacjaThe publication presents methodology developed for determination of linear viscoelasticity limits for cold recycled mixtures with cement and bituminous emulsion using Simple Performance Tester (SPT). Methodology was verified on reference materials (PCV and steel dummy specimens, cement concrete and asphalt concrete) to comply with elasticity and viscoelasticity theory. The developed methodology enabled determination of linear viscoelasticity...
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An experimental study of high-hydrogen welding processes
PublikacjaThis paper presents investigation results of determination of the diffusible hydrogen content in deposited metal obtained by means of two most often used methods-the glycerin method and the mercury method. Relation has been defined between results of those methods in the area characteristic of low-hydrogen as well as high-hydrogen welding processes. Relations available in the literature do not include the diffusible hydrogen content...
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Badania nośności na zginanie innowacyjnego kształtownika giętego na zimno typu GEB
PublikacjaLekkie konstrukcje metalowe wytwarzane z kształtowników giętych na zimno to jedna z najszybciej rozwijających się dyscyplin w zakresie budownictwa. Do niedawna profile gięte na zimno stosowano wyłącznie jako elementy drugorzędne, czyli płatwie oraz rygle. Nowo opatentowany przekrój typu GEB ma być wykorzystywany jako element nośny konstrukcji ramowych. Jednak jego zaistnienie na rynku budowlanych konstrukcji metalowych jest uwarunkowane...
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Stability and limit load analysis of a cold-formed channel section column
PublikacjaThe paper presents stability and limit load analysis of a steel column 1440 mm high of a cold-formed channel section, subjected to a combination of compression and bending. Experimental results were compared to the resistance of a code procedure and to the outcome of numerical non-linear analysis. Comparison was made of numerical solutions by means of static (Riks) and dynamic (Explicit and Implicit) methods. Perfectly elastic...
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Experimental Testing of Innovative Cold-Formed "GEB" Section / Badania Eksperymentalne Innowacyjnego Kształtownika Giętego Na Zimno Typu „Geb“
PublikacjaOne of the major advantages of light gauge steel structures made of cold-formed steel sections is their low weight, so manufacturers are increasingly using the possibilities of those sections for the production of typical single-storey steel structures systems. Well known profiles, such as Z, C and the so called hat sections that have been studied and described in the literature, are used mainly as purlins or truss components....
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Preliminary experimental research on stability of truss' joint with positive eccentricity
PublikacjaRecently, a very large interest in lightweight steel structures made from cold-formed sections has been noticeable. In the design practice, a large emphasis is put on rational shaping of both the thin-walled elements and constructions designed on them. The aim of this paper is to present the methodology for preparation of experimental research that model the behaviour of members in trusses made of cold-formed sections with positive...
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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
PublikacjaIn 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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TRUSS JOINT WITH POSITIVE ECCENTRICITY EXPERIMENTAL RESEARCH
PublikacjaDue to the technological reasons in modern lightweight steel trusses, fabricated from cold- formed sections, positive eccentricities appear in the truss nodes what induce additional forces in the truss chords. To account for the real load-carrying capacity of truss node area the steel structure research in scale 1:1 were conducted. The experiments consisted of two parts: preliminary and proper one, when conclusions from...
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Corrosion behavior of concrete produced with diatomite and zeolite exposed to chlorides
PublikacjaChloride induced reinforcement corrosion is widely accepted to be the most frequent mechanism causing premature degradation of reinforced concrete structures. The electrochemical impedance of reinforcing steel in diatomite- and zeolite-containing concrete exposed to sodium chloride was assessed. Chemical, physical and mineralogical properties of three concrete samples (20% diatomite, 20% zeolite, and a reference containing neither)...
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IMPACT-TOUGHNESS INVESTIGATIONS OF DUPLEX STAINLESS STEELS
PublikacjaDuplex stainless steels are very attractive constructional materials for use in aggressive environments because of their several advantages over austenitic stainless steels. Duplex steels have excellent pitting and crevice corrosion resistance, are highly resistant to chloride stress-corrosion cracking and are about twice as strong as common austenitic steels. Better properties are associated with their microstructures consisting...
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Ocena odporności na pękanie podbudów drogowych z mieszanek mineralno-cementowo-emulsyjnych (MCE)
PublikacjaPodbudowy z mieszanek mineralno-cementowo-emulsyjnych (MCE) są jednym z wielu materiałów stosowanych do wykonywania warstw nawierzchni w ramach przebudów dróg w Polsce. Mieszanki MCE pozwalają na maksymalne powtórne wykorzystanie istniejących warstw konstrukcyjnych do budowy lub przebudowy nawierzchni. Do wykonania podbudów z MCE stosuje się materiał pochodzący z rozbiórki istniejących warstw (destrukt) bitumicznych, warstw związanych...
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Innovative cold-formed GEB section under compression
PublikacjaCold-formed steel sections extensively affect the modern steel construction industry. Not only are they used as secondary elements like purlins or sheeting, but also they can serve as primary load-bearing members in fabricated steel panels and trusses. A new cross-section called shortly a GEB may serve as that member. However, its existence of the metal building structures industry depends on the exact, optimal dimensional parameters...
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Effect of wet Hydrogen Sulfide on Carbon Steels Degradation in Refinery Based on Case Study
PublikacjaMaterial degradation caused by wet hydrogen sulfide (Wet H2S) is one of the major issues in refineries. Carbon steel is the main construction material used in refineries and is subjected not only to thickness loss but the hydrogen is the major concern. H2S leads to high atomic hydrogen penetration in steel which causes degradation in the form of blistering and/or cracking (HIC/SOHIC) and stress cracking in the area of welds and...
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THE INTERACTION BETWEEN STEEL COLUMN CHORD AND CLOSELY SPACED REINFORCEMENT.
PublikacjaNowadays, more often than before, civil engineering designers are willing to use steel build-up members composed of single or doubled cold-formed chords interconnected using different mechanical connectors. This paper subject is an analysis of cooperation of a closely spaced built-up cold-formed chord interconnected with series of bolts that are located along the length of the member in a specific spacing. This distance along the...
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Selected local stability problems of channel section flanges made of aluminium alloys
PublikacjaThe paper addresses the issue of local buckling of compressed flanges of cold-formed thin-walled channel columns and beams with nonstandard flanges composed of aluminium alloys. The material behaviour follows the Ramberg–Osgood law. It should be noted that the proposed solution may be also applied for other materials, for example: stainless steel, carbon steel. The paper is motivated by an increasing interest in nonstandard cold-formed...
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Effect of water salinity on properties of multipass underwater wet manual metal arc welded joints
PublikacjaThe weldability of steel under the water is limited due to the influence of the environment. Water causes limited visibility, presence of the residual stresses, increasing the cooling rate, and increasing the diffusible hydrogen content in deposited metal, leading to the formation of brittle microstructures in heat-affected zone (HAZ). The paper presents the results of mechanical properties testing of S420G2+M steel welded joints...
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Selection of Electrode Material for Inconel 617/P92 Steel SMAW Dissimilar Welds
PublikacjaThe present work aimed to investigate the microstructure and mechanical properties of the dissimilar shielded metal arc welded (SMAW) joint of Alloy 617 and P92 steel for advanced ultrasupercritical boilers. The SMAW joint was produced using three different types of electrodes, namely, ENiCrFe-3, ENiCrMo-3, and ENiCrCoMo-1. During microstructural observation of the welded joints, no possible cracking was detected in the weldments....
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Zagrożenia korozyjne stali nierdzewnych w przemyśle spozywczym
PublikacjaPrzedstawiono przyczyny występowania zagrożeń korozyjnych stali nierdzewnych w przemyśle spożywczym. Szczegółowo omówiono mechanizm oraz sposób zapobiegania korozji wżerowej, szczelinowej oraz pękania korozyjnego. Zaprezentowano dokumentację fotograficzną omówionych typów korozji. Wskazano podstawowe problemy związane z doborem materiałów konstrukcyjnych do budowy instalacji w przemyśle spożywczym.
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Shear fracture of longitudinally reinforced concrete beams under bending using Digital Image Correlation and FE simulations with concrete micro-structure based on X-ray micro-computed tomography images
PublikacjaThe paper presents experimental and numerical investigations of the shear fracture in rectangular concrete beams longitudinally reinforced with steel or basalt bar under quasi-static three point bending. Shear fracture process zone formation and development on the surface of beams was investigated by Digital Image Correlation (DIC) whereas thorough analyses of 3D material micro-structure, air voids, width and curvature of shear...
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Buckling Analysis of Cold Formed Silo Column
PublikacjaThe paper is devoted to stability analysis of different models of steel cold formed silo column. The steel cylindrical silos are often composed of corrugated walls and vertical open-sectional columns uniformly placed along the silo circumference. Both the whole 3D silo, a simplified model consisting of one column with a part of the silo walls, and a single column resting on elastic foundation provided by the silo walls were analyzed....
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The Effect of Cryogenic Treatment on Microstructure and Mechanical Response of AISI D3 Tool Steel Punches
PublikacjaRecently, deep cryogenic treatment is performed to improve the mechanical responses (wear, hardness, fatigue, and thermal conductivity) of various steel components. Researchers have tried to evaluate the eco-friendly and nontoxic process to optimize the parameters. Cold-shearing punches used to manufacture various holes that undergo severe impact loading and wear in the metal forming process. This study concerns the effect of soaking...
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Effect of Arc Strikes on High Strength Low Alloy Steels Welded by SMAW
PublikacjaWet welding with covered electrodes (Shielded Metal Arc Welding – SMAW) is the most commonly used method of carrying out welding repair works in a water environment. Limited visibility and the inability to move freely under water result in an increased risk of formation of welding imperfections such as lack of fusion, lack of penetration and arc strikes. The work focused on changes in the properties and structure of steel subjected...
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Fatigue Bending of V-Notched Cold-Sprayed FeCoCrNiMn Coatings
PublikacjaCold-spray coatings were produced by FeCoCrNiMn high-entropy alloy powders deposited on carbon steel substrate. The coatings were realized at intermediate temperature and high pressure (at 1100 °C and 7 MPa). The coating microstructure was characterized by scanning electron microscopy and X-ray diffraction, revealing a very dense deposition and high flattening ratio of the splatted particles. This had a large influence on the...
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Normal stress distribution in built‑up cold‑formed column in relation to interconnecting bolt spacing
PublikacjaIn order to increase a stiffness of cold-formed steel (CFS) elements it is practised to built-up the cross-section. In the analysed case, a main element is strengthened by adding extra chord in contact partially along the column. This additional chord acts as a longitudinal stiffener connected with the main section by series of bolts. Authors check whether rules applied over the years, for hot-rolled elements, can be indiscriminately...
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Hydrogen Damage in Superaustenitic 904L Stainless Steels
Publikacjaresults on the influence of hydrogen on corrosion resistance and of hydrogen embrittlement of 904L superaustenitic stainless steel were investigated. The cracking behavior was studied by performing a slow strain rate test in synthetic seawater under varying cathodic polarization conditions. The results showed that the steel’s plasticity varied with the applied cathodic current density. Significant reductions in ductility were found,...
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Zastosowanie techniki ściegu odpuszczającego do spawania mokrego
PublikacjaW artykule przedstawiono zastosowanie techniki ściegu odpuszczającego do poprawy właściwości złączy ze stali konstrukcyjnych wykonywanych w warunkach mokrego spawania pod wodą. Scharakteryzowano spawanie mokre elektrodami otulonymi zmiany struktury i właściwości złączy spawanych przez nakładanie ściegów odpuszczających. Przedstawiono metodykę oraz wyniki badań metalograficznych i twardości próbek ze stali konstrukcyjnej o podwyższonej...
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A brief note on monotonic and fatigue fracture events investigation of thin-walled tubular austenitic steel specimens via fracture surface topography analysis (FRASTA)
PublikacjaThe main objective of this short communication is to show the fracture progression in each loading case and complement knowledge about fracture mechanisms underpinning the tensile and fatigue performance of thin-walled tubes. For this purpose, the fracture surface topography analysis (FRASTA) method was used in the thin-walled tubular austenitic stainless-steel specimens. Two cases were analyzed: monotonic tension, and uniaxial...
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Właściwości stali S460M napawanej pod wodą metodą lokalnej komory suchej
PublikacjaW artykule przedstawiono wyniki badań próbek ze stali S460M wykonanych pod wodą metodą lokalnej komory suchej. Pomiary twardości oraz analiza strukturalna wykazały, że dla określonych ilości wprowadzonego ciepła możliwe jest wykonanie złączy bez niezgodności spawalniczych. Stwierdzono formowanie się w pewnych warunkach pęknięć zimnych w SWC wywołanych procesami odprowadzania ciepła z materiału, które są charakterystyczne dla spawania...
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Mechanical and fracture properties of concrete reinforced with recycled and industrial steel fibers using Digital Image Correlation technique and X-ray micro computed tomography
PublikacjaPaper presents investigation of fracture phenomenon in plain concrete and in concrete reinforced with both recycled steel fibers (RSF) and industrial steel fibers (ISF). The wedge splitting test (WST), which enables stable crack propagation for quasi-brittle materials, was carried out on 75 75 75 mm cube samples. Initially, fracture process zone development was investigated only on the surface of samples using Digital Image Correlation...
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Sulfate‐reducing bacteria‐assisted hydrogen‐induced stress cracking of 2205 duplex stainless steels
PublikacjaThe paper presents the results of a laboratory investigation of the microbiologically assisted hydrogen‐induced stress cracking (HISC) of 2,205 duplex stainless steel (DSS). The testing of susceptibility toward HISC was performed with two different methods. Precharged in sulfate‐reducing bacteria (SRB), inoculated medium samples were subjected to slow strain‐rate testing in artificial seawater. In situ constant load tests were...
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Impact of Geometrical Imperfections on Estimation of Buckling and Limit Loads in a Silo Segment Using the Vibration Correlation Technique
PublikacjaThe paper examines effectiveness of the vibration correlation technique which allows determining the buckling or limit loads by means of measured natural frequencies of structures. A steel silo segment with a corrugated wall, stiffened with cold-formed channel section columns was analysed. The investigations included numerical analyses of: linear buckling, dynamic eigenvalue and geometrically static non-linear problems. Both perfect...
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Storage of High-Strength Steel Flux-Cored Welding Wires in Urbanized Areas
PublikacjaThe condition of the consumables is a key factor determining the waste reduction in the welding processes and the quality of the welded joint. The paper presents the results of tests of four types of fux-cored wires dedicated for welding high-strength steels, stored for 1 month and 6 months in Poland in two urbanized areas: in a large seaside city (Gdańsk) and in Warsaw, located in the center of the country. The wires were subjected...
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Impact performance of novel multi-layered prepacked aggregate fibrous composites under compression and bending
PublikacjaMulti-layered Prepacked aggregate fibrous composite (MLPAFC) is a new type of concrete, which is prepared in two subsequent stages of aggregate-fibre skeleton prepacking and cementitious grouting. In this study, ten MLPAFC mixtures were prepared in three subsequent layers incorporating different contents of four different types of steel fibres. Long and short hooked-end and crimped steel fibers were adopted with 3.0 and 1.5% dosages...
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Effects of preheating on laser beam–welded NSSC 2120 lean duplex steel
PublikacjaDuplex stainless steels show sustainable alternative for the conventional austenitic grades, with higher strength, higher resistance against stress corrosion cracking, and lower purchase cost. Thus, duplex stainless steel gains more attention in construction, oil and gas, and chemical industries. Among duplex stainless steels, low nickel and low molybdenum alloyed lean duplex stainless steel are a cost-efective substitution of...
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The influence of reinforcement on load carrying capacity and cracking of the reinforced concrete deep beam joint
PublikacjaThe paper presents the results of experimental research of the spatial reinforced concrete deep beam systems orthogonally reinforced and with additional inclined bars. Joint of the deep beams in this research was composed of the longitudinal deep beam with a cantilever suspended at the transversal deep beam. The cantilever deep beam was loaded throughout the depth and the transversal deep beam was loaded at the mid-span by longitudinal...