bluuebunny/crossref_metadata_2025 huggingface dataset:
16.18: DYNA® link anchor box: Innovative structure for anchoring stay cables
Authors: Gawlista Jannik , Kasper Marcel , Schraml Marcus , Brand Werner
Published: September 2017

Cable stayed and extradosed bridges are often designed with saddles at the pylon. This results in slender dimensions of the pylon and reduced costs as access shafts within the pylon can be omitted. However, inspection of the deviated strands within the saddle is only possible after exchanging single strands or the complete cable. Furthermore, differential forces in the cables are often transferred within the saddle by friction only. Also, cable installation and stressing have to be carried out simultaneously on both fronts of the form traveller for the most common balanced free cantilever construction method.

To find an alternative solution for an improved performance of pylon design, installation cycle and cable inspection, a new curved anchor box has been developed. The DYNA® Link anchor box consists of two sections: in the concrete, there are two steel beams with shear studs for transferring the cable load into the concrete pylon; outside, the concrete the steel beams are connected to each other, and a bearing plate is welded to the steel beams as support for the cable anchorage. An opening at the steel beam provides access for installation and inspection of the cable anchorage. Through this steel anchor box, which is embedded in the solid concrete pylon, two stay cable anchorages are linked to each other and are located outside the pylon. With this design, all advantages of common saddles are kept; the disadvantages are compensated by using a steel composite structure which can be designed and calculated according to national or international standards. In doing so, elaborate testing in accordance to international cable guidelines such as fib or PTI can be omitted as well.
16.21: Evaluation of existing railway bridges
Authors: Bujnak Jan , Gocála Jozef , Hlinka Richard
Published: September 2017

This article is not available for publication.
16.26: Design and construction of composite bridges
Authors: Marcussen Jens Brolev
Published: September 2017

Composite bridges, where steel girders are used compositely with a concrete deck slab, can be preferred over steel or concrete bridges due several reasons. They are less expensive and require less maintenance than orthotropic steel decks and they are lighter than concrete girders. They often require less temporary structures for execution and by using prefabricated elements fast erection can be achieved. Composite bridges are often chosen for span ranges that are in between the typical span ranges of concrete and steel bridges.

When designing a composite bridge deck it is important to carefully consider the different material characteristics of steel and concrete to achieve an optimum design both in respect of erection sequence and material quantities. The concrete slab has a high resistance to compression forces whereas steel is prone to buckling, but has a high tension capacity.

The Constantine ramp bridges (Algeria, 2014) are open steel box girders with a filigran concrete slab. They are located on steep slopes in a congested urban area, which gave limitations to the construction methods. A composite deck solution was chosen so that steel segments could first be lifted into place by a medium size crane and secondly prefabricated concrete slab filigran members could be placed on the steel and used as formwork for the final in situ casting of the concrete slab. The construction sequence was planned so that the concrete slab would be mainly in compression in the dead load situation to optimize material quantities.

Composite bridge decks are often applied in cable stayed bridges, since the concrete slab has good abilities to resist the high compression induced by the inclined cable stays particularly near the towers. Examples of recent composite cable stay bridges are Busan Bridges (Korea 2014, main span 475 m) and New NY Bridge (New York, under construction, main span 366 m) where bolted wide flange steel girders were used in combination with a concrete slab and Sungai Johor Bridge (Malaysia 2013, main span 500 m) where an open box section was applied.

Composite bridge decks are often used in combination with all steel or all concrete decks to balance the weight when for example the main span is very large compared to the back spans such as for the Stonecutters bridge (Hong Kong, 2009, Main Span 1018m).
16.29: Determination of the residual stress distribution of steel bridge components by modelling the welding process
Authors: Van Puymbroeck Evy , Nagy Wim , Schotte Ken , Ul‐Abdin Zain , De Backer Hans
Published: September 2017

Welding operations are typically used for the connections in steel bridges. Several locations with residual stress concentrations exist within the welded parts due to the welding itself, but also because of the influence of geometric discontinuities on the flow of the stresses. This can result in fatigue failure. The knowledge of residual stresses is essential to determine the effect of the residual stresses on the fatigue life behaviour of the welded components [1].

In this paper, the residual stresses of two flat plates of construction steel S235 welded together are determined by modelling the welding process. The temperatures during the welding operations are calculated in a thermal analysis, taking into account the thermal properties and behaviour of the steel. The heat input during welding is implemented on the model by defining a thermal flux for the different time steps representing the passage of the welding torch. A double ellipsoidal volume heat source is used to describe the heat flow through the material for a moving heat source. The distribution of the thermal flux is considered, taking into account the thermal material properties of steel as a function of temperature. After the calculation of the temperatures introduced during the welding process in the thermal analysis, a subsequent mechanical analysis is performed. The temperatures are introduced as a time dependent load onto the model. The elements of the model in the fusion zone of the welding are activated based on their reached temperature. The finite element modelling predicts the residual stresses induced by the welding procedure which can later be verified through comparison with measured residual stress distributions.
16.31: Use of API specified steel tubes for infrastructure applications in Europe
Authors: Karamichalis Nikolaos , Benfield Simon , Rafiu Hussain
Published: September 2017

The lack of ready availability of large diameter steel tubes/pipes (greater than 508mm) which are CE marked for use in Europe can often cause delays in construction. There can also be minor or major alterations in design when alternative tube sections which are already available are proposed. In the UK highways network, large diameter tubes are extensively used for sign and signal support cantilever gantries and the demand for them can be very high for the highways market, often with very short delivery programme requirements. Following the cessation of the rolling of large diameter tubes from UK mills, the alternative options for cantilever gantries are either to amend the design using a truss leg formed from smaller hollow sections, to source a CE marked tube from outside the UK, or to use tubes specified to the American Petroleum Institute (API) which have ready availability from the oil and gas market.

This last option is discussed and a comparison review is undertaken for tube sections specified between API Specification 5L [1, 2] and BS EN 10210/BS EN 10219 [3, 4] for hot rolled/cold formed sections. This study has already been used and accepted by the Technical Approval Authorities of the UK's primary road network, Highways England, for highway gantries, and therefore can validate the use of API specified tubes (which are a common by product material from the Oil and Gas industry, the tubes in question being effectively off cuts from pipeline construction), for broader infrastructure applications. This is a significant contribution in the construction sector especially in high demand periods for steel tubes, with added value from the reduction of carbon footprint caused by using already fabricated surplus material.
01.03: Behaviour of bolted endplate connections of beams subjected to bi‐axial bending moments and axial forces
Authors: Couchaux Maël , Rodier Anthony
Published: September 2017

In recent years, the use of finite element analysis software even more efficient and the construction of more complex steel structures favoured 3D modelling. After performing the global analysis, designers often get forces and moments in three dimensions at the location of endplate connections, either for beam‐to‐beam joints or column bases. Eurocode 3 part 1–8 only provide method to check bolted endplate connections for the combination of an in‐plane bending moment and an axial force. The out‐of‐plane bending moment is not considered. A research has been conducted to provide a design method, based on the component method of EN 1993‐1‐8, to assess the resistance of endplate connections subjected to in‐plane and out‐of‐plane bending moments, and an axial force. The objective of the present paper is to present the results obtained for endplate connections of beams. The conservative aspect of the method was validated by comparison with numerical results.
17.05: Advanced framework for suction bucket jacket design
Authors: Clausen Henrik Bisgaard , Pedersen Ronnie Refstrup
Published: September 2017

The suction bucket is a well know foundation concept from the oil and gas industry and the concept is now adopted in the foundation of jacket substructures for offshore wind turbines. The suction buckets transfer the loads from the jacket to the soil and it is essential to include the jacket‐bucket‐soil interaction.

Ramboll has developed a framework for the design of suction buckets, where both in‐place and installation scenarios are included.

In this paper, we will discuss the important features included in the framework and the steps required delivering an optimized and fabrication friendly bucket design. A major challenge is to determine the foundation loads and corresponding soil stiffness for the jacket design and installation support conditions for the bucket design.

It is essential to assess the short and long‐term global and local interaction between jacket/bucket as well as the bucket/soil interaction during installation to ensure that the strong suction pressure can be safely applied. The interfaces between the structural and geotechnical designs are further challenging for multiple foundations in a wind farm with varying water depths and soil conditions. The importance of focus on the safe design of this thin walled structure and the importance of managing the interfaces in such projects are highlighted in this paper.

The framework for verification of suction bucket foundations involves the interfaces between geotechnical design, efficient load calculation, structural design and production. A detailed design involves numerous calculations on the buckling capacity of the bucket skirt and lid subjected to ultimate loads as well as design for fatigue.
18.03: Comparative analysis of steel telecommunication tower: By using V shaped & L shaped hot rolled steel profiles under design & fabrication stage
Authors: Ciliz Serap , Tunc Bahadir , Guler Saziye Gulden
Published: September 2017

The purpose of this paper is to minimise the cost of steel telecommunication lattice self‐supported towers by using V shaped hot rolled steel profiles. Comparative analyses were carried out for different tower heights using different configuration of V shaped and L shaped hot rolled steel profiles. An elastic 3D truss finite element model was used to determine the axial forces and stresses in each member under wind and various antenna load cases. Strength and serviceability limit states were controlled according to ANSI/EIA/TIA‐222‐G (addendum 2) during design stage. For the cost optimisation, both production, manufacturing, installation and material costs were addressed. During manufacturing stage, there are many obstacles to manufacture V shaped steel profiles, but the results indicate that the minimum cost solution corresponds to V shaped steel profiles.
19.02: Exploring the potentials of metal foams in structural elements for civil/building applications
Authors: Faiella Diana , Viscovo Simona , Mele Elena
Published: September 2017

Sandwich foam beams and panels, made of solid skins and aluminium foam core, are widely applied in high‐tech engineering fields; on the contrary structural use in the civil engineering field is not so common.

An initial, explorative study on the structural application of metal foams in the civil and building engineering field is presented in this paper. The potentials of sandwich foam beams, made of solid skins (aluminium or steel) and aluminium foam core, are studied through analytical models and parametric analyses. The sandwich flexural response is investigated under four point bending test. For this purpose, an analytical tool able to provide design indications for sandwich foam beams is presented and applied in a parametric analysis, adopting some commercial aluminium foams and skins both in steel and aluminium alloys.

The cross section failure modes under bending action (namely: skin fracture, core fracture, face wrinkling,) are studied, and failure mode maps are proposed for different combinations of solid‐skins–foam‐core in order to identify the dominant failure mode varying the skin thickness to beam depth ratio for practical design purposes. An experimental campaign is being planned to validate the presented results.
19.03: Amager bakke: Design challenges for a steel building with a recreational roof
Authors: Nordestgaard Peter Madsen , Højgaard Arndt Casper , Rizvan Patrik , Husbjerg Jens
Published: September 2017

In every way, Amager Bakke is a spectacular construction. The 43,000 m2 combined waste to energy plant and artificial ski slope has a full height of 85 m. In its final form, the roof will provide public access for a park with the size of 2½ soccer fields. The park includes hiking, climbing, skiing area, viewing platform, and a café.

The building has a high complexity due to several reasons. The exterior architectural expressions require the correct shape for a double curved skiing slope. This is merged with the interior demands for waste to energy machinery. The result was a complex geometrical structure for which steel was the only feasible material to apply when forming the superstructure. Furthermore, the fire compartmentation of the energy plant and the park gave special design issues concerning structural robustness and municipality's approval of the regulatory fire safety strategy. Finally, the roof needed to be prepared to carry natural trees.

Early in the engineering process it was decided that an innovative approach was required. Therefore, the limits of BIM tools were challenged and widened. The 3D‐model has produced more than 3,000 drawings, and all structures are designed in the model. The model was also used for design layout, collision check, quantity surveyor, and for performing a building sequence illustration the erection timeline. Additionally, the model was continuously operated for interchanges with the client, the architect, and the contractor.

The steel superstructure was executed in S235, S355, and S460 steel. A total of approximately 7,500 tons of weight was applied to the building parts. Various forms of large span roof steel girders were used with different static systems, to carry ∼1,000 concrete slab elements on the roof. The facade is covered with ∼1,000 aluminum bricks on steel sandwich panels and the cantilevered chimney hangs on the gable side starting more than 50 m above ground level and reaching 124 m above ground level. This construction required a tuned mass damper in the top, which gave rise to an interesting calibration to the actual natural frequency. The building complex also includes an 11‐storey office building, which caused additional demands regarding acoustical vibrational damping through the structures. It was solved by an innovative damped floor construction.
19.04: Diagrid: the renaissance of steel structures for tall buildings geometry, design, behavior
Authors: Mele Elena
Published: September 2017

Structural configurations best addressing the traditional requirements of strength and stiffness for tall buildings are the ones employing the tube concept, whose efficiency, however, is strictly related to the involved shear‐resisting mechanism. In this perspective, diagrid structures – the latest mutation of tube structures – show an extraordinary efficiency, related to the adopted geometrical pattern: thanks to the triangle tessellation of the façades, internal axial forces are largely prevalent in the structural members, thus shear lag effects and racking deformations are minimized. Being also adaptable to whatever surface, diagrid is becoming the most used structural solution for tall buildings of complex form. In this paper some specific design issues for diagrid structures are identified, namely: the relative importance of strength and stiffness design criteria, as well as to the need of secondary bracing systems for counteracting the inter‐module flexibility effects. Simplified procedure for dealing with such issues are proposed and design implications are discussed.
19.06: The Blue Planet: A simple building concept for spectacular geometry
Authors: Nordestgaard Peter Madsen , Wyrtz Mikkel , Tinning Henrik
Published: September 2017

The article is about how straight steel beams are used to form the spiral‐curved building of The Blue Planet.

The building's architecture was inspired by the circulating currents of a whirlpool. From the entrance, the visitor steps into the vortex of the whirlpool – the round lobby – and is drawn inside the spiral. The building's form also provides a fifth façade, which can be seen from the air and thus during the descent to Copenhagen Airport.

In order to make the structure buildable and at the same time keep the cost as low as possible the curving geometry is entirely made out of straight steel beams.

The steel frames consist of many steel beams and the curving geometry of the building is formed from the multiple layers of the façade, which includes both C‐profile steel elements and a series of waterproofing and insulating membranes, fiber‐cement plates and aluminum plates that are bent to generate the curved shapes. Curving consists of 33,000 identical shingle elements that fold over the surfaces provided by the C‐profiles. The profiles rest on supports, here called swords, that are arranged according to an innovative concept in lengths adapted from the frames, so the façade plates can be bent on site. The relatively heavy and dense façade system is also necessary to exclude noise from Copenhagen Airport.

The only curved steel element is found in the round shape of the foyer, which is formed by a ring beam 600 mm deep. All of the curves within the aquarium's five swirling arms are created by the careful arrangement of straight steel beams that form a total of 54 uniquely shaped frames. Built‐up sections form the different standard designed steel framing elements which are all welded individually due to the variation in frames. Although each frames cross section measures 300 mm in width, the depths range from 300 to 800 mm and the spans reach up to 30 m in length. The frames within each whirlpool arm feature the same radial center, meaning if they extended far enough they would all pass through the same point. A series of steel braces, X‐shaped in design, are also positioned at strategic locations to stabilize the structure against wind and other horizontal forces.
19.07: The steel roof of the new Lille Stadium: Its mechanical scheme, its assembly and erection sequences
Authors: de Ville de Goyet Vincent , Duchene Yves , Gens Frédéric , Seret Sébastien
Published: September 2017

For the UEFA Euro 2016, France built 6 new stadiums including the stadium ‘Pierre Mauroy’ in Lille, whose total area is approximately 50000 m². Its steel roof is generated by simple cylindrical and spherical shapes. The stadium can house fully indoor or partly covered events thanks to a 120 × 80 m2 movable roof. Therefore, the North and South roof areas are locally lowered to allow the opening of the central movable sections. The main characteristics of the project are:

‐ the two 200 meters long mega‐trusses supporting the steel roof,

‐ the static scheme of the structure, limiting the internal forces induced by temperature variations,

‐ the technique used to assemble the mega‐trusses and the erection method, with, in both case, the same goal : to save time.

Valode & Pistre and Pierre Frenet are the architects of the project. Greisch provided the engineering office and Eiffage Métal was the steel construction company.
19.08: College of Falkonergården, Frederiksberg, Denmark: Structural and architecturally innovative multifunctional steel hall
Authors: Vanggaard Ole , Weidemann Hans Chr. , Nordestgaard Peter Madsen
Published: September 2017

The new multifunctional hall of Falkonergårdens Gymnasium and the associated foyer opened in 2015 and can be used by up to 1,000 people. The same year, it was awarded a prize by Frederiksberg Municipality as one of the city's finest buildings. In 2016, the building also received this year's “Store Arne”, awarded annually by the Danish Association of Architects for work that raises the standards of architecture in Copenhagen.

The ‘multihall’ for Falkonergården in Copenhagen has a covered steel structure. It is a structure that maximizes the use of the shape with interacting plate action and “membrane” action in the cylindrical walls. The basic structural behavior is without use of primary structural members in bending. It has an orthogonal space structure for the upper roof; it has no horizontal bracing, but is only stabilized for horizontal shear forces by a closed kidney‐shaped ring beam without bending. The structural spaceframe roof has maximized the production possibility of the use of large fully fabric‐welded trusses bolted together on site with welded plane cross members. The structural design of the roof space frame allowed erection in only two days without use of scaffolding. Very simple structural freeware has been a help in the sketch design stage.

The aim of the steel design was to find a synthesis of architecture, structural behavior, productivity and buildability. It was a very challenging job, although full understanding is only for people with X‐ray eyes! (Fig. 1 and 2).
21.01: Fatigue prevention retrofit for connections of main girder to transverse beam or sway bracing in steel bridges
Authors: Ichinose Luiza Hiroko , Koyama Masahiro , Sakano Masahiro
Published: September 2017

In recent years, a large number of fatigue damages in steel bridges has been successively reported in Japan and the numbers still show tendencies to increase with the progressive aging of the Japanese bridge stock. To assure the bridge safety and its adequate structural performance, appropriate fatigue counter‐measures are required, not only to retrofit the weakened structural members, but also to avoid the further growth of the existing cracks and prevent the occurrence of new ones.

The present study focused on two different fatigue damage types, one occurring at the connection details of transverse beam flanges inserted through a slot in the intersecting girder web, and the other, occurring at the welding line between the upper end of vertical stiffeners and the girder upper flange. Preventive retrofitting measures were proposed for these details and applied to a bridge in service that had been constructed more than 40 years ago. Stress measurements under service load were carried out in situ, before and after the execution of fatigue preventive retrofitting works so as to verify the effectiveness of the proposed retrofit methods.

The results showed that, for the details of transverse beam lower flange inserted through an intersecting girder web, the stresses around the slot end area were considerably reduced after the execution of the proposed retrofits. As for the details of vertical stiffeners upper end, the stresses around the plate edge after the execution of the retrofitting works decreased significantly.

Based on the stress range obtained from field measurements, fatigue life for each location was evaluated. The results for the details of the transverse beam flange intersecting the girder web, lead to fatigue life values that were at least 4 to 6 times of their values before retrofitting and, with one exception, the results for vertical stiffener upper end detail retrofits presented fatigue life values that were more than 2 times the fatigue life of that of their original detail, confirming thus the effectiveness of the proposed retrofitting methods.
21.08: Evaluation of steel buildings by means of non‐destructive testing methods
Authors: Fox Christian , Doktor Dipl.‐Math. Markus , Kurz Wolfgang , Seiler Georg , Wu Haoran , Boller Christian
Published: September 2017

Non‐destructive testing (NDT) methods have become increasingly attractive for verification of existing steel infrastructure including buildings. However destructive testing is still state of the art combined with load condition monitoring and yield limit determination of the steel elements incorporated in buildings.

In many of the existing buildings, the characteristics of the steels used are often not known anymore. A statement of the residual load‐bearing capacity such as of incorporated steel beams within a building can be made if there is a means to determine it reliably. This opportunity principally exists via micromagnetic as well as ultrasonic measurements to be shown here. Magnetism even allows the yield strength of ferromagnetic steel beams to be determined. An ultimate limit state design can be proven by real material characteristics where model uncertainties have been excluded and not by selected minimum values only.

If the residual load‐bearing capacity of steel beams cannot be guaranteed today, higher static loads can only be transferred by strengthening measures, such as welding or bolting additional parts. However, if the true loading as well as material condition could be determined those measures might be avoidable. A means on how to do this is by ultrasonic measurement since the propagation speed of ultrasonic waves in a steel is influenced by its strain and stress conditions. Acousto‐elastic characteristics show the correlation between the propagation of speed and the current state of stress. Those characteristics have therefore been determined on beams in lab tests and compared to strain gauge measurements, where the acoustic wave speeds have been determined first as a speed without the influence of load, before loaded conditions were considered.

Material texture due to rolling processes plays a significant role in steel structures too. It has a ten times higher influence on the ultrasonic measurements than stresses due to loading have. Hence a clear separation between texture and stress related influences is therefore essential. Particularly since all those measurement results may further be exposed to significant scatter, statements regarding confidence bands of the determined stresses have to be made. This therefore includes statistical tests that will provide the respective reliability required for the concept to be competitive. The respective NDT techniques combined with suitable stochastic methods are shown below.
P05.01: Simulation of the spatial behaviour of tubular façade scaffolding
Authors: Dolejš Jakub , Ilčík Jiří
Published: September 2017

An advanced analysis of spatial interaction between the elements of tubular scaffolding has been carried out at the Czech Technical University in Prague. Experiments focusing on rotational stiffness of the common couplers have been performed. The resulting stiffness (semi‐rigid connections), eccentricities etc. have been implemented into spatial models and a detailed GNIA analysis followed. The results of calculations performed on simple and complex models and a recommendation for the most effective computation models has been presented. The recommendations have been implemented in the following research of the scaffold anchoring. This paper research was essential for the related development of the new scaffold anchor, which successfully overcomes the problems with insulated building facades.
P10.01: Comparative numerical buckling analysis: Of compressed carbon and stainless steel members at elevated temperatures
Authors: Dobrić Jelena , Spremić Milan , Marković Zlatko , Ninić Bojana , Milovanović Jovana
Published: September 2017

Although all metals lose strength and stiffness when they are exposed to fire, the reduction of mechanical properties considerably varies between different metals. In contrast to carbon steel, austenitic stainless steel has better response at elevated temperatures due to relatively high content of alloying elements. The type of metallurgical microstructure crucially affected on material response and global behaviour of structural elements under fire conditions. Despite the fact that carbon steel and stainless steel have different constitutive patterns, EN 1993‐1‐2 states that resistance of structural elements made from these materials should be checked using the same fire design procedure. This paper presents numerical analysis of buckling resistance of compressed members exposed to fire, without fire protection. Finite element analysis is conducted using the ABAQUS software. The study points out the structural performance of columns made of stainless steel cold‐formed hollow section and hot‐rolled I‐section in grade 1.4301 and identical columns from carbon steel grade S235 at high temperatures. Sensitivity to initial imperfections is also assessed. The thermal and mechanical properties of carbon and stainless steel are taken from EN 1993–1‐2. Development of temperature into the columns in fire condition is obtained from standard fire curve, according to ISO834. The numerical predictions of buckling response are compared with results of design procedure according to Eurocodes EN 1991–1‐2 and EN 1993–1‐2. The aim of this paper is estimation of acceptability and accuracy level of the mentioned design guidelines in the treatment of buckling phenomena of stainless and carbon steel structural elements at elevated temperatures.
P11.02: Experimental analysis and FE modeling of square hollow sections under combined axial and bending loads
Authors: Mitsui Kazuya , Sato Atsushi , Latour Massimo , Piluso Vincenzo , Rizzano Gianvittorio
Published: September 2017

The seismic performance of steel frames strongly depends on the non‐linear behaviour of beams and column because the plastic zones are concentrated in beams’ ends and at the base of the columns of the first storey. Therefore, in order to guarantee an appropriate behaviour of the whole frame, it is necessary to characterize the response of steel member up to failure. Dealing with the characterization of the non‐linear response of beams, many experimental works are currently available both for I and hollow sections. In addition, predictive models based on regression analyses able to provide both the ultimate resistance and rotation capacity of steel members, even though they always make reference only to the case of pure non‐uniform bending. As previously mentioned, the overall frame response is strongly influenced also by the non‐linear behaviour of columns, and an accurate prediction of their combined axial and bending vs rotation response is needed in order to control the seismic behaviour of the frame. In order to predict the ultimate resistance and rotational capacity of steel members subjected not only to bending but also to axial loads, two kinds of experimental testing and an analysis joint activity carried out. The monotonic behaviour of SHS subjected to bending only or combined bending and axial loads are investigated. Subsequently, numerical analysis are conducted to extend the experimental sample. At the end, the results of the experimental end FE work are used to calibrate a model able to express the ultimate resistance of SHS as a function of the main geometrical and mechanical parameters of the section.
P16.01: Brief survey of the Chacao bridge girder design
Authors: Gogny Eric , Jakobsen Svein Erik , Mhamed Aymen Cheikh
Published: September 2017

This article is not available for publication.
01.11: NUMERICAL ANALYSIS OF FULL STRENGTH HEAVY BEAM‐TO‐COLUMN BOLTED CONNECTION
Authors: Lisec Damjan , Može Primož
Published: September 2017

The design of full strength bolted beam‐to‐column beams considering the overstrength factor for the beam material according to EN 1998‐1 is particularly demanding, especially in case of heavy beam profiles in combination with higher grade material (e.g. S355). The elastic design of the full strength connection leads to very stocky joint. The component method presented in EN 1993‐1‐8 that was developed mainly for the design of partial‐strength joints may also be used for the design of these connections, but its application is limited mainly to experts.

This paper studies bolted beam‐to‐column joints under monotonic and cyclic loading, particularly hot rolled HEA 600, S355 beam with high bending strength. Two different configurations of bolted connection of HEA 600 to column are studied in order to achieve full strength connection as defined in EN 1998‐1, namely eight‐bolt rib stiffened and haunched stiffened joint configuration. Both joint configurations are first calculated according to EN 1993‐1‐8 using component method, where bolt forces and joint bending strength were determined. The first joint is also designed according to the procedure given in ANSI/AISC 385‐10. The numerical model, based on this design, was built in FE software Abaqus in order to observe the behaviour under monotonic and cyclic loading. The cyclic loading was defined according to the ECCS and ANSI/AISC 341‐10 procedures. The bolt preload was also studied.
01.12: Development and validation of design criteria for free from damage steel joints
Authors: D'Aniello Mario , Zimbru Mariana , Latour Massimo , Francavilla Antonella , Landolfo Raffaele , Piluso Vincenzo , Rizzano Gianvittorio
Published: September 2017

Seismic response of steel structures in case of destructive events strongly depends on their ability to dissipate seismic energy. Traditional design of steel Moment Resisting Frames (MRFs) is based on the assumption that this energy is dissipated by steel members or connections. In the former case, full strength joints are adopted and plastic hinges are developed in beam ends while, in the latter case, partial strength connections are adopted, promoting the plastic engagement of some of the connections’ components. In both cases, the design for rare seismic events concedes high levels of damage in some structural parts, requiring high costs for the retrofit. In order to overcome this drawback, recently, the FREE from DAMage design strategy has been proposed as a combination of partial strength and supplementary energy dissipation strategies. Indeed, in previous works, a new joint typology called FREEDAM, has been conceived with the aim to avoid the structural damage (even in case of rare seismic events), thanks to the capacity of the connection to withstand high rotations without developing any plasticization of the steel parts. More specifically, a FREEDAM connection is a connection where friction dampers are introduced at the level of the beam bottom flange. The main feature of this connection is that its resistance and rotational capacity are very easy to control by means of a proper calibration of preload applied to the friction pads with high strength bolts and length of slotted holes, designed to allow the relative movement between the beam and the column. Within this framework, in this paper, the attention is focused on the behaviour of two possible types of FREEDAM connections. In addition, design rules for the friction components of the connections are also discussed. The design procedure is developed in view of application of a hierarchical design, applied at the level of the joint components, able to concentrate energy dissipation in the friction damper and to avoid any damage to all the other parts. The effectiveness of FREEDAM connections is subsequently verified by means of finite element simulations under both monotonic and cyclic loading.
01.15: Numerical investigation of preloaded gusset plate connections between polygonal built‐up members
Authors: Jovašević Slobodanka , Rebelo Carlos , Pavlović Marko , Veljković Milan
Published: September 2017

In the last decades, the demand for renewable energies, including wind energy, is increasing. With this increase, more powerful wind energy converters are needed, which require higher supporting structure that allow to reach zones of higher wind speed with less turbulences. The most commonly used type of the tower is steel tubular tower. Height of these towers is limited by manufacturing and transportation logistics. The solution to overcome these issues might be construction of lattice towers. The major disadvantage of lattice towers is large number of the installed bolts. Therefore, the steel hybrid tower that combines the advantages of steel lattice (lower part) and tubular tower (upper part) was proposed in SHOWTIME project. The sections used in lattice portion of the tower are built‐up polygonal sections composed of cold‐formed pieces connected together with preloaded bolts. The goal with using built‐up polygonal cross‐section is to minimize number of connections by increasing the member length. The focus in this paper is numerical investigation of preloaded gusset plate connections between these types of members. The finite element software ABAQUS has been used in the study. The aim of the investigation is to determine the failure modes of the elements and connections, as well as stiffness and ultimate resistance of the connections.
01.21: Static and cyclic behaviour of bolted gusset plate connections: Numerical and analytical modelling
Authors: Couchaux M. , Martin P.O. , Rodier A.
Published: September 2017

In dissipative seismic concept according to Eurocode 8, capacity design leads to additional cost for brace connections. In this concept, connections, either bolted or welded, don't dissipate energy, this role being dedicated to braces. However bolted gusset plate connections of brace are able to dissipate energy by sliding, bearing and block shear. Within the RFCS project Meakado, the seismic behaviour of these shear joints and their influence on the global resistance of the concentrically braced frame (CBF) have been studied performing time history analysis on CBF structures where springs were introduced at the location of connections. To calibrate this spring model, tests on bolted connections of single channel and double angles have been performed by Tecnalia during this project and completed by a numerical simulations based on the finite element code ANSYS. The results of the numerical simulations are presented in this paper. The model is firstly confronted to experimental tests and a parametrical study has been carried out to extend the domain of validity and particularly to study connections of tubes. Finally, an equivalent spring model, based on the component method of Eurocode 3, supposed to represent the behaviour of connections in seismic nonlinear analyses is developed.
01.23: Seismic design of full‐strength full‐ductility extended endplate beam‐to‐column joints
Authors: Francavilla Antonella B. , Latour Massimo , Piluso Vincenzo , Rizzano Gianvittorio
Published: September 2017

The analysis and modelling of the ultimate behaviour of the beam‐to‐column connections is certainly one of the most studied topics in the field of steel structures. In particular, seismic design of steel frames is commonly carried out to assure the dissipation of the seismic input energy in the so‐called “dissipative zones” which have to be properly detailed in order to assure wide and stable hysteresis loops. Once avoided the yielding of columns, beam‐to‐column joints play a role of paramount importance. In fact, beam‐to‐column joints can be designed either as Full Strength (FS) or Partial Strength (PS). In the first case, the seismic input energy is dissipated by means of plastic cyclic excursions of the beam ends. In the second case, dissipation requires the plastic engagement of ductile joint components.

This paper addresses the design criteria to be adopted to assure a full‐strength full‐ductility behaviour of Unstiffened Extended End‐Plate (U‐EEP) beam‐to‐column joints. The validation of the design procedure is accomplished by three‐dimensional finite element analyses with ABAQUS 6.13 software.
01.24: Moment‐resisting beam‐to‐column connections of corrugated web I sections
Authors: Aydın Recep , Yüksel Ercan , Yardımcı Nesrin
Published: September 2017

Thin sinusoidal corrugated web I‐sections have been utilizing commonly in recent years. Though, there are scarce number of studies about their connections.

The moment‐resisting extended end plate type beam‐to‐column connections of sinusoidal corrugated web I sections are assessed by means of experimental studies to reveal the important response characteristics. Three full scale beam‐to‐column connections were tested in the Structural and Earthquake Engineering Laboratory of Istanbul Technical University. Although two of the specimens have corrugated‐web panel zone, the third one has relatively thicker flat plate in the panel zone and its near‐vicinity. Double diagonal stiffeners are used in the sinusoidal panel zone of one specimen.

It is obtained that two distinct specimens exhibit the comparable responses in terms of the stiffness and strength properties.
01.26: Reliability assessment of flange cleat beam‐to‐column joints
Authors: Skejic Davor , Rizzano Gianvittorio , Curkovic Ivan
Published: September 2017

This paper deals with the reliability assessment of the flange cleat beam‐to‐column steel joints. Based on the set of tests of flange cleat beam‐to‐column joints the experimental bending resistance and stiffness has been obtained. Theoretical bending resistance and stiffness have been evaluated using existing and proposed (modified) mechanical models that were developed to account for the effect of stiffened cleats. Models uncertainties have been evaluated based on the comparison of the experimental and theoretical values. The limit state equations have been defined for each joint type and each theoretical model considered. The reliability indices for resistance and stiffness of joints were evaluated using FORM (First Order Reliability Method), SORM (Second Order Reliability Method) and AS (Adaptive Sampling). The obtained values of reliability index were discussed as well as the sensitivity factors of basic variables and sensitivities of reliability index to mean value and standard deviation of basic variables. Finally, a conclusion was based on the comparison between the results obtained from deterministic (semi‐probabilistic) and probabilistic approach. The probabilistic approach demonstrated differences in respect to deterministic approach and pointed out the importance of using stochastic assessment for determination of the optimal theoretical model. From the probabilistic approach, optimal resistance models are EC3 model – method 2 for joint types with unstiffened top cleat and Faella model for joints with stiffened top cleat. Considering stiffness, Faella model is optimal for joint types with unstiffened top cleat, while for joints with stiffened top cleat no model is reliable enough. Nevertheless, because of its low reliability, EC3 stiffness model is not recommended for use with considered joint types. It is clear that stiffness of this type of joints requires further research and that the shortcoming of Eurocode in this issue should be solved in the second edition of the code.
02.01: Development of a new design approach for weldings
Authors: Stroetmann Richard , Kästner Thoralf , Werner Lars
Published: September 2017

The application of high strength steels provides economic and ecological advantages in many types of constructions, due to the resource‐conserving material use. However, for welded constructions, some of these advantages are partially offset by conservative design rules and more complicated execution regulations. The objective of the ongoing AiF‐FOSTA research project P1020 is the development of principles, which lead to significant improvements of design and execution rules for welded connections of high strength steel structures. The development of design rules aims at a simpler and economically more efficient execution. This paper gives an overview of the research project P1020, including the design model, the assessment of the welding processes and the parametric studies, consisting of load bearing tests and numerical simulations. It describes the development of the flat tensile test method for the assessment of the welding behaviour and the structural analysis of welded joints for parametric studies.
02.05: Design of concrete‐filled steel tubular longitudinal gusset plate connections
Authors: Chen Ju , Zhu Ji‐hua , Xu Fei , Xue Wen
Published: September 2017

Experimental investigation on the concrete‐filled tubular gusset plate T–connections is presented in this paper. Three different loading conditions, including axial tension, eccentric tension and in‐plane bending, were applied to the brace of connection. The chord wall slenderness ratio (D/t) of the test specimens ranged from 48 to 75. Each connection was tested to failure, and the behavior under loading was recorded. Punching shear failure of the chord member was the main failure mode observed during the tests. It is recommended that the contribution of concrete be considered in the design because it could effectively restrain the deformation of the chord wall that was observed in the test. The proposed design equations predict the ultimate strengths of the concrete‐filled tubular gusset plate T–connections generally well.
02.08: The influence of plate thickness on the welding residual stresses from submerged arc welding in offshore steel structures
Authors: Andreassen Michael Joachim , Yu Zhenzhen , Liu Stephen , Nielsen Jens Henrik
Published: September 2017

Welding‐induced residual tensile stresses and distortion have become a major concern in relation to the structural integrity of welded structures within the offshore wind industry.

The stresses have a negative impact on the integrity of the welded joint, as they promote distortion, reduce fatigue life, and attribute to the corrosion cracking and brittle fracture in the weld components.

This study investigates the influence of plate thickness on the welding‐induced residual stresses. The residual stresses are investigated through experiments and in accordance with existing production procedures leading to a better understanding of the distribution and development of the welding residual stresses. This can later be used to optimize the fatigue design, providing a more efficient and improved design. In this context, the current research is expected to benefit the offshore industry by leading to an improved design, which consequently may be included in future norms and standards.

Submerged Arc Welding (SAW) was used to make a fully penetrated butt weld in 10 mm and 40 mm thick steel plates with the same welding parameters as used in the production procedures.

The base material is thermomechanical hot‐rolled low‐carbon fine‐grained S355ML steel in accordance with the European standard DS/EN 10025‐4 [1].

The welding temperature profile during welding was recorded by embedded thermocouples and the hole‐drilling method was used to measure the near‐surface residual stress state.