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PL
W artykule przedstawiono podstawowe informacje na temat wykorzystania membran polimocznikowych jako wysoko efektywnego systemu zabezpieczającego konstrukcje stalowe przed korozją. Opisano podstawowe zalety i wady tego rodzaju izolacji, ze szczególnym uwzględnieniem ich wykorzystania jako powłoki antykorozyjnej. Zaprezentowano dwa przypadki realizacji: silosu stalowego na mikrokrzemionkę i podziemnego zbiornika na wodę amoniakalną.
EN
The article presents basic information on the use of polyurea membranes as a highly effective system protecting steel structures against corrosion. The basic advantages and disadvantages of this type of insulation are described, with particular emphasis on their use as an anti-corrosion coating. Two implementation cases were presented: a steel silo for microsilica storage and an underground ammonia water tank.
EN
The main aim of this work is a computational nonlinear analysis of a high strength steel corrugated-web plate girder with a very detailed and realistic mesh including vertical ribs, all the fillet welds and supporting areas. The analysis is carried out to verify mechanical structural response under transient fire temperature conditions accounting for an efficiency and accuracy of three various transient coupled thermo-elastic models. All the resulting stress distributions, deformation modes and their time variations, critical loads and eigenfrequencies as well as failure times are compared in all these models. Nonlinearities include material, geometrical and contact phenomena up to the temperature fluctuations together with temperature-dependent constitutive relations for high strength steel. They result partially from steady state and transient experimental tests or from the additional designing rules included in Eurocodes. A fire scenario includes an application of the normative fire gas temperature curve on the bottom flange of the entire girder for a period of 180 minutes. It is computed using sequentially coupled thermo-elastic Finite Element Method analyses. These account for heat conductivity, radiation and convection. The FEM model consists of a combination of 3D hexahedral and tetrahedral solid finite elements and uses temperature-dependent material and physical parameters, whose values are taken after the experiments presented in Eurocodes. Numerical results presented here demonstrate a fundamental role of the lower flange in carrying fire loads according to this scenario and show a contribution of the ribs and of the welds to the strength of the entire structure.
EN
The Search for Hidden Particles (SHiP) experiment is a new general-purpose fixed target facility proposed at the CERN Super Proton Synchrotron (SPS) accelerator to search for long-lived exotic particles associated with Hidden Sectors and Dark Matter. This paper reports on the structural design of SHiP’s decay volume, a > 2000 m3 conical vessel under vacuum that should host several large particle physics detector systems. In the field of structural and seismic engineering, the design study in a very multidisciplinary international collaboration has represented a stimulating research challenge. The goal of the design of the decay is to produce a structure as light and as slim as possible to stay within the geometrical envelop determined in the physics simulations. A complete study has been performed with all the steps from the conceptual design, including the interaction with other components and the plant systems, to the assembly procedures for the decay volume realization. The complexity of the case study has been driven by the need of finding the appropriate compromise between the physics performance, the structural aspects, the executive, constructive and operational issues, and the economical constraints. The assembly strategy, the welding techniques, and the expected construction time are discussed in view of the extremely complex installation phase. Building Integrated Model (BIM) methodology is also proposed as an essential tool to coordinate the entire process of designing and managing not only the decay volume but the entire project.
4
Content available remote Wybrane aspekty projektowania belek ażurowych
PL
W artykule przedstawiono dwa podejścia do analizy statycznej i wymiarowania belek ażurowych. Na przykładzie belki swobodnie podpartej porównano tradycyjną metodę analityczną (model belki Vierendeela) z modelowaniem numerycznym wykorzystującym powłokowe elementy skończone. Wymiarowanie belki ażurowej w obu przypadkach przeprowadzono dla stanu granicznego nośności (SGN) i użytkowania (SGU). W ramach stanu granicznego nośności przeprowadzono zarówno weryfikację nośności przekroju w przekrojach krytycznych, jak i weryfikację nośności elementu, uwzględniając możliwość jego zwichrzenia. Moment krytyczny belki ażurowej wyznaczono, korzystając z liniowej analizy wyboczeniowej. Wszystkie obliczenia przeprowadzono w programie do obliczeń inżynierskich (AxisVM).
EN
The article presents two approaches to the static analysis and dimensioning of cellular beams. A simple supported cellular beam was solved analytically by means of the Vierendeel model and numerically with the use of triangular shell finite elements. In both cases, the ultimate and serviceability limit states were verified. In the case of the ultimate limit state (ULS) the cross-section resistance and lateral-torsional buckling resistance were considered. The critical bending moment was obtained by means of linear buckling analysis. All calculations were carried out in a programme for engineering calculations (AxisVM).
PL
W artykule zostały omówione praktyczne aspekty analizy plastycznej w odniesieniu do projektowania stalowych konstrukcji prętowych. W ramach poruszanego tematu w pierwszej kolejności zostały przedstawiona istota analizy plastycznej i zdefiniowane pojęcia nośności krytycznej oraz przegubu plastycznego. Następnie zwrócono uwagę na znaczenie stopnia statycznej niewyznaczalności konstrukcji w kontekście analizy plastycznej. W kolejnym kroku omówiono zawarte w Eurokodzie 3 kryteria stosowania analizy plastycznej, jakie muszą spełniać materiał i analizowana konstrukcja. Rozważania zostały podsumowane eksperymentem numerycznym obejmującym analizę plastyczną układu ramowego, który przeprowadzony został w programie AxisVM przeznaczonym do analiz inżynierskich.
EN
In the paper, the practical aspects of the plastic analysis of the steel frame structures are presented. Firstly, the importance of plastic analysis is discussed. Secondly, the defi nitions of critical load capacity and plastic hinge are given. Thirdly, the importance of the degree of static indeterminacy in the context of plastic analysis is highlighted. Furthermore, the limitations of the use of plastic analysis defi ned in Eurocode 3 are referred to the requirements related to steel grade and the static scheme of a structure. The considerations are summarised with a numerical experiment of the plastic analysis of a steel structure performed in the engineering program AxisVM.
EN
The knowledge of the load in prestressed bolted connections is essential for the proper operation and safety of engineering structures. Recently, bolted joints have become an area of intensive research associated with non-destructive diagnostics, in particular in the context of wave propagation techniques. In this paper, a novel procedure of bolt load estimation based on the energy of Lamb wave signals was proposed. Experimental tests were performed on a single lap joint of two steel plates. Ultrasonic waves were excited and registered by means of piezo-electric transducers, while precise measurement of the bolt load was obtained by means of using the force washer transducer. Experimental tests were supported by the finite element method analysis based on Schoenberg’s concept. The results showed that the relationship between the bolt load and signal energy was strongly nonlinear and it depended on the location of acquisition points.
8
Content available remote Diagnostyka elementów konstrukcji stalowych
PL
W artykule przedstawiono wybrane badania diagnostyczne elementów konstrukcji stalowych. Przeprowadza się je zarówno na etapie kontroli jakości podczas procesu wytwarzania konstrukcji, jak i przy diagnozowaniu uszkodzeń elementów w trakcie eksploatacji. Aby uniknąć uszkodzeń, w czasie badania zazwyczaj stosuje się metody nieniszczące. W artykule omówiono badania powszechnie wykonywane, takie jak np. badania penetracyjne, magnetyczno-proszkowe czy ultradźwiękowe, ale także takie, które dopiero od niedawna są stosowane, np. badanie prądami wirowymi czy emisją akustyczną. Pokazane zostały również uszkodzenia elementów konstrukcji występujące w budownictwie incydentalnie oraz badania rzadko wykonywane.
EN
The paper presents selected diagnostic tests of steel construction elements. These tests are carried out both at the stage of quality control during the construction process and damage diagnosis of components during exploitation. To avoid damage during the test, non–destructive methods are usually used. The paper discusses commonly performed tests such as penetrant, magnetic-particle or ultrasonic tests, but also those that have only recently been used, for example, eddy currents or acoustic emission method. Also damage to structural elements occurring in construction incidentally are shown and rarely performed tests are described.
EN
The paper presents the analysis of the influence of fasteners and connections flexibility on displacements of symmetrical single-bay pitched-roof steel building, including trapezoidal cladding acting as a diaphragm. The purpose of the article was to compare numerical models with and without taking into consideration fasteners and connections flexibility in order to observe the differences in transverse stiffness of the building during modifying model from the simple one to more complex and precise. The analyses were carried out for the 3D structure. Fasteners and connections were substituted by equivalent beam finite elements. Corrugated sheets were replaced by three types of equivalent orthotropic shell models and the influence of the choice of the model on the stiffness of the building was observed. The results showed that in the analysed structure the flexibility of fasteners and connections has negligible effect on transverse displacements of the building in the case of four sides fastening of the sheeting, however in the case of two sides fastening the influence significantly increases.
EN
This article aims at presenting the basic principles of designing steel structures according to Eurocode PN-EN 1993-1-2, i.e. with respect to ensuring the appropriate level of safety for such structures in case of a fire developing into flashover. The load-carrying capacity of a steel structure, serving as an example, was assessed on the basis of a static strain-stress analysis. The analysis was conducted regarding changes in the temperature of structural members, both the exposed and the fireproof protected ones, under fire conditions.
11
Content available remote Analiza zdolności poszycia z płyt warstwowych do stabilizacji płatwi
PL
W artykule przedstawiono analizę możliwości stabilizacji zginanych elementów konstrukcji hali przez obudowę z płyt warstwowych. W rozważaniach uwzględniono zarówno ograniczenia wynikające ze sztywności poszycia, jak również z nośności połączeń pomiędzy płytami warstwowymi a płatwiami. W tym celu wykorzystano procedury normowe oraz wzory dostępne w literaturze przedmiotu, jak również własne badania numeryczne i doświadczalne. Wyniki analizy skłaniają do zachowania daleko idącej ostrożności w wykorzystywaniu poszycia z płyt warstwowych do stabilizacji płatwi.
EN
An analysis of the ability of sheeting made of sandwich panels to stabilize hall structure elements under bending has been presented in the article. Limitations due to sheeting stiffness, as well as the resistance of connections between sandwich panels and purlins have been included in the considerations. Code procedures and formulas from the literature of the subject, as well as our own numerical and experimental studies have been used for this purpose. The results of the analysis urge users to be extremely cautious when using sheeting from sandwich panels for the stabilization of purlins.
PL
Dobór stali do zbrojenia betonowych obiektów mostowych w Polsce bardzo często ogranicza się do określenia klasy wytrzymałości A-IIIN, zgodnej ze starymi normami do projektowania, które nadal są powszechnie stosowane. Zapis taki notorycznie pojawia się w specyfikacjach technicznych dla wielu obiektów mostowych w Polsce.
PL
Jak wynika z najnowszych raportów, w najbliższych latach w Polsce możemy spodziewać się przyspieszenia inwestycyjnego w segmencie inżynieryjnym. W planach mamy realizację dużych projektów infrastrukturalnych – mostowych, hydrotechnicznych i drogowych. Przedstawiane programy inwestycyjne dają nadzieję na utrzymanie dobrej koniunktury w tej branży.
EN
Steel structures designed according to Eurocode 3 are executed in accordance with the provisions of the standard PN-EN 1090-2, which is referred to in Eurocode 3. In addition, the standard PN-EN 1090-2 refers to in its content a number of welding standards, e.g. PN-EN ISO 9692-1. These standards provide guidelines for welded connections, which should be applied in the case of joints connecting steel hollow sections. Analysis of above-mentioned provisions revealed that for fillet welds they are simultaneously fulfilled only if the inclination angles of the elements are in the range of 70°-100°. According to recommendations of PN-EN 1993-1-8 and EN 1090-2, the same weld type around the perimeter of the element connected to the chord of lattice structure is possible to execute only for inclination angle lower than 60°. Discrepancies between these standards also exist with regard to the interpretation of the dimension of the flare groove welds in connections of rectangular hollow sections with the same width. In addition, analyses of the recommendations for welding in cold-formed zones indicate that, for steel grades currently used for the production of cold-formed rectangular hollow sections, welding in these zones is not permitted only for profiles with wall thickness equal to 12.5 and 16 mm. The above-mentioned issues point out the need for mutual unification of standards for the design and execution of steel joints in hollow sections.
EN
The buildings with great grandstands are the public places where consequences of failure are very high. For this reason, according to EN 1990 they belong to CC3 class consequence of failure. The reliability class RC3 is associated with the consequences class CC3 [7, 8] and is defined by the β = 4.3 reliability index with probability of failure pf ≈ 8.54·10-6. Shear connections have to transfer forces between structural members – steel body and bolts with adequate degree of safety. The load-carrying mechanism of bolted shear connections is complex and analytical methods for predicting the shear resistance are not applicable. Instead the resistance of the connections may be determined using empirical formulas. The distributions of horizontal and shear resistance within steel body - bolts will be described depending on material characteristics of steel body and bolts components. The characteristic resistance of steel shear connection is obtained as minimum of two variables: bolds resistance and steel body resistance. Probability function of this minima will be defined and described in this paper. Laboratory tests provide the only practicable basis for specifying safety margins for ultimate strength connections. The determination of partial safety factors within shear connections will be presented according to EN1990. Design value of such resistance is specified as suitable fractile of log- normal probability distribution, calculated with the assumption that the acceptable probability of down-crossing is not greater than pf,ult ≈ 2.91·10-4. It means that the target reliability index, defined for the resistance, is taken as βR.req = 3.44, in accordance with the European recommendations (EN 1990).
EN
The hollow section welded joints require a number of actions before starting welding and appropriate supervision during this operation to achieve joints with adequate quality level, which should be confirmed by the post-completion tests. The execution of hollow section joints is associated not only with welding, but also with cutting and additional machining of edges. In some cases, weld surfacing is also applied to correct sections fit-up. Weld surfacing and thermal cutting can cause local hardening of connected elements. The welding has to be preceded by an assessment of the previous technological processes. The welded joints can be only executed on the basis of detailed Welding Procedure Specifications (WPS). It is advisable to manufacture - in accordance with previously prepared WPS - pre-production joints for testing, proving the ability of the welding personnel to execute welded joints with specified quality, using the available equipment. The quality of welded joints is proved by testing. A type of conducted tests, thus scope and type of welding defects possible to detect, depends on the weld type, wall thickness of connected elements and joint geometry. The authors’ experience indicates that the proper execution of the welded joint of hollow sections is difficult task, which often requires pre-production quality testing of the joints.
PL
W artykule omówiony zostanie proces zmian naprężeń i odkształceń dla profilu energochłonnego kl. 4 o przekroju kwadratowym w wyniku ściskania osiowego, wyrażony za pomocą aparatu matematycznego, pozwalającego na określenie nośności granicznej takiego profilu, którego zastosowanie w postaci podłużnic, spotykamy we współczesnych konstrukcjach nadwozi samochodowych. Elementy, takie tworzą tzw. strefę kontrolowanego zgniotu, przejmując część energii uderzenia, jednocześnie odpowiadając za progresywny charakter deformacji tego obszaru.
EN
The article discusses the process of stress and strain changes for an energy-intensive profile with a square crosssection as a result of axial compression, expressed using a mathematical apparatus that allows determination of the load-bearing capacity of such a profile, the use of which in the form of stringers is found in modern automotive body constructions. Elements, such as the so-called a zone of controlled crumpling, taking over part of the impact energy, at the same time being responsible for the progressive nature of the deformation of this area.
18
Content available remote Numerical modelling of innovative DST steel joint under cyclic loading
EN
This paper addresses the numerical simulation of an innovative double split Tee beam-to-column joint fitted with a dissipative friction damper, recently proposed at the University of Salerno. The innovative connection prevents damage to all other structural components with the exception of one component of the connection that is specially designed to dissipate the input energy of a seismic hazard by means of the slippage of a friction material. The main topics herein presented are the development of a strategy for the numerical modelling of complex friction problems and a detailed numerical model of the overall beam-to-column joint equipped with the friction device. The joint is subjected to both monotonic and cyclic loading conditions. The numerical modelling was developed using the Finite Elements Method (FEM) with Abaqus Software. Sliding force–displacement curves are obtained for two damper materials and an estimation of their wearing is presented. To evaluate the accuracy of the numerical model, moment–rotation curves of the joint are compared with the experimental curves. The FE results show good correlations and confirm the potential interest of this novel joint typology to achieve easily replaceable details in case of a seismic event.
19
PL
W artykule przeanalizowano efektywność wzmocnienia kątownika przez dodanie dodatkowego elementu, mocowanego do elementu wzmacnianego w wybranych punktach. Siłę w węzłach końcowych przykładano do pręta wzmacnianego, co wynika z rozwiązań często stosowanych w praktyce. Pojedynczy pręt z imperfekcją łukową obciążano przed wzmocnieniem siłą osiową mniejszą od jego nośności. W analizie nośności pręta złożonego powstałego na skutek dodania dodatkowej gałęzi uwzględniono wspomniane obciążenie wstępne w chwili wzmocnienia, mimośrodowość przyłożenia obciążenia, podatność połączeń oraz możliwość uwzględnienia uplastycznienia przekroju w kątowniku pierwotnym (wzmacnianym). Oszacowane wartości nośności porównano z nośnością pręta wykonanego od początku jako złożony i obciążony mimośrodowo. Określono wstępnie proponowany obszar prac badawczych w omawianym w artykule zakresie.
EN
In this article effectiveness of strengthening of angle member by use of additional “new” member that is attached to the “old” member in selected points was analysed. The loading force was applied at the end points of “old” member intended to be strengthened. This way of load application is a result of the solutions commonly used in practice. Single bar with initial bow imperfection was loaded before strengthening with axial force lower than its load capacity. In the presented analysis of built-up member formed thanks to new branch addition, the aforementioned initial loading force was included as well as load eccentricity, joint flexibility and plasticization of cross-section of strengthened angle. Estimated load capacities were compared with load capacity of a member that was initially prefabricated as a built-up member, eccentrically loaded. An experimental research program including problems mentioned in this article was initially mentioned.
20
Content available remote Analiza spawalności konstrukcji spawanych ze stali HSS i UHSS. Cz. 2
PL
Przeprowadzono analizę wymagań stawianych projektantom i wykonawcom nowoczesnych stalowych konstrukcji spawanych oraz zagadnienia jakości wykonania tych konstrukcji. Przedstawiono analizę pojęcia „spawalność” konstrukcji spawanych z uwzględnieniem czynników metalurgicznych, technologicznych i konstrukcyjnych. Podano przykłady podziału złączy spawanych konstrukcji stalowych w zależności od stanu wytężenia złączy i związanych z tym wymaganiami jakości złączy.
EN
An analysis of the requirements for designers and contractors of modern steel welded structures made of HSS and UHSS steels and the production quality of these structures was carried out. An analysis of the concept of „weldability” of welded structures considering metallurgical, technological and structural factors is presented. Examples of quality classes of welded joints of steel structures are shown, depending on the stress level of welded joints and resulting welded joints quality requirements.
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