bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vehicle‐Bridge‐Interaction in the Dynamic Calculation of Railway Bridges: Case Study and Dynamic Analysis for 75 Existing Simply Supported Bridge Structures of the Austrian Railway Network
Authors: Glatz Bernhard , Fink Josef 
Published: September 2019

ABSTRACTThe dynamic calculation of railway bridges for high speed traffic has become a topic of great interest for engineers and researchers in recent decades. Certain velocities of a crossing train can lead to resonance phenomenons, either caused by consecutive axle loads or the critical velocity of one single load. In these cases, the bridge structure is exposed to excessive vibrations that lead to vertical accelerations and deflections. In order to avoid track irregularities and the risk of derailment as a possible consequence, the limits for vertical accelerations are prescribed in European and national standards.The results of dynamic calculations depend on the level of detail of both, the bridge model and the vehicle model. This paper focuses on the influence of the vehicle model for 75 existing simply supported bridges (15 steel structures, 2 composite steel and concrete structures, 11 filler beam structures and 47 concrete slab structures) in the Austrian railway network. The commonly used Moving Load Model (train modelling as a series of moving loads) is compared to the more sophisticated Detailed Interaction Model (train modelling as a combination of masses, springs and dampers) of the Railjet train. The bridge structures are modelled as simply supported Bernoulli‐Euler beams. It is shown, which potential is hidden in the more complex and time intensive calculation with the Detailed Interaction Model compared to the Moving Load Model. Furthermore, the validity of the Additional Damping Method is analysed.
Problems and Innovative Solutions in Retrofitting and Enhancement of Existing and Historical Railway Steel Bridge
Authors: Mezzi Marco , Petrella Paolo , Cavacchioli Luca , Cefaliello Vincenzo , Nestovito Gianluca , Spirolazzi Gabriele 
Published: September 2019

ABSTRACTMany existing steel bridges of the railway network are significantly old, sometimes ancient and even historical. They continue to be in use for different reasons but require retrofitting works to be preserved or to be safely operational. The paper deals with two emblematic cases of such bridges. The first one is a historical iron bridge built in the last decades of 19th century. It consists of a slender parabolic grid arch having a span of about 150m sustaining a boxed beam having a total length of 266 m with a lower railroad deck and an upper roadway deck. The bridge is very amazing for both the aesthetical aspect and the engineering concept. The second bridge was rebuilt immediately after WW2 and represents a typology largely present along the Italian railways. It has three spans of simply supported steel truss beam, for a total length of 142 m. The paper illustrates the works able to increase the residual service life considering various options for the future use. The retrofitting strategy, the enhancement level, the constructive solutions, sometimes very innovative, are critically discussed with the aim of a generalization of the proposed scheme, paying some attention to the cost/effectiveness ratios.
Optimisation of Retrofitted Steel Bridge Girders Subjected to Fatigue Loading
Authors: Mirza Olivia , Fieck Syhra , Pathirana Sameera , Mashiri Fidelis 
Published: September 2019

ABSTRACTThe RMS is responsible for the upkeep of more than 5600 bridges within NSW, with an estimated replacement cost of $15.35 billion (1). Of these bridges, it is estimated that 12% are approaching 70 years of service life and 50% are more than 40 years old (1, 2). As a result, a significant amount of bridges are structurally deficient, as they were never designed for the traffic loads or frequencies they are subjected to today (2). The increased weight and frequency of traffic has a serious impact on the fatigue life of steel bridges, and if appropriate retrofit methods are not implemented, then it inevitably becomes necessary to replace the bridge at great expense. This study examined the suitability of bolted retrofit plates to remediate and prevent fatigue fractures in the tension flange of bridge girders, focussing on the effects that the gap between the bolt and bolt hole has on the development of composite action. This was achieved by carrying out a parametric study on various bolt hole sizes and examining the effects on girder stiffness and ultimate load carrying capacity. It was found that bolt hole size has significant impact on how early in loading, composite action is initiated, and how much the girder needs to deflect before composite action is fully developed. The results showed that a bolt gap greater than 0.5mm could have significant impact on the overall performance of the girder, both in terms of serviceability and ultimate load carrying capacity.
Smooth Hysteretic Model of H‐shaped Steel Beams
Authors: Ohtani Yuka , Idota Hideki 
Published: September 2019

ABSTRACTSteel frame structures are generally designed with a beam‐collapse mechanism in mind. Beam members are important earthquake‐resistant elements that dominate the behavior of an entire structure during an earthquake. In order to improve the structural design of such beams, it is important to clarify their performance during cyclic loading, because beams are subjected to a cyclic bending moment under the influence of seismic forces. Hysteretic models have been proposed for each slenderness ratio of lateral buckling for H‐shaped steel beams with lateral buckling. However, this provides inconsistent results and a lack of continuity. Since lateral buckling is a continuous process, it is more reasonable to use a hysteretic model containing continuous parameters.In the present study, we develop a simple smooth hysteretic model that is valid for all lateral buckling slenderness ratios. We applied the that proposed hysteretic model for the reinforced concrete structure to H‐shaped steel beams. In the proposed hysteretic model, which involves an H‐shaped steel simple beam undergoing bending at one‐end, the behavior of the weakened area when the maximum loading capacity has been exceeded can be expressed using two parameters: the lateral buckling slenderness ratio and the standardized width thickness ratio. In addition, we also propose a hysteretic model that can be adapted for a uniformly distributed bending moment and an antisymmetric bending moment. We expect that simple smooth hysteretic model can be applied to a wide range of H‐shaped steel beams.
Oodi – Helsinki Central Library: Making the architectural vision a reality
Authors: de Neumann Simon 
Published: September 2019

ABSTRACTThe Helsinki Central Library is a landmark project, delivered as part of the “Finland 100” programme to celebrate 100 years of the independence of Finland. ALA architects delivered the winning entry to the architectural competition held in 2013. In 2014 Ramboll Finland won the structural design contract for the project, taking the project from conceptual architectural design through to completion of construction in 2018.The main structural system is fundamentally a steel frame solution designed to Eurocode. Two EXC4 classified, 109m span, tilted arches carry the two main floors and roof of the building. Post‐tensioned cables tie the bases of the arches to provide a tied‐arch structure. Other post‐tensioned cables in the floor system and concrete cores hold the tilting arches in position. Transverse trusses allow the cantilevering balcony to be delivered. 2400t of steel have been used to deliver the main frame structural solution.With careful and considered design, fabrication and construction, high quality to good tolerances and stringent requirements have been successfully achieved.An overview of the bridge‐like structural system that has been conceived and developed for the project shall be presented. Some of the challenges encountered and resolved in the design shall be discussed, as well as an overview of key decisions made to handle project delivery budget and timetable requirements.
Kistefos Museum: Transforming great architecture into buildable project
Authors: Tornsberg Niels , Møller‐Hansen Lars Olaf 
Published: September 2019

ABSTRACTKistefos Museum is a museum bridge of about 80 meters in length spanning approximately 60 meters over a river situated inside a hilly forest in Norway. The museum is designed by BIG and Ramboll has, as the main advisor for the turnkey contractor, designed the steel structure which twists 90° over a length of 24 meters mid span.During the design process, state‐of‐the‐art software has been used for the collaboration between the architect, the engineers and the contractors (Rhinoceros, Grasshopper and Tekla Structures). The Engineering part has included software for seismic analysis, vibrational analysis, and effects of composite floor structures (Robot Structural Analysis), plus software for designing steel connections (IDEA Statica).The steel bridge itself has been an engineering challenge, but the erection of the bridge proved no less of a challenge, as it involved a big interim bridge to ensure the stability of the museum while the steel components and façades were mounted.
Understanding the buckling behavior of cold‐formed steel members with slotted web by using cFEM
Authors: Ádány Sándor 
Published: September 2019

ABSTRACTIn this paper the buckling of lipped channel cold‐formed steel members with slotted web is discussed. These members typically have complicated buckling behaviour, since it is a combination of various types of buckling, such as lateral‐torsional buckling, distortional buckling, plate buckling, web crippling, or shear buckling. Though it is practically desirable to separate the various buckling types, this cannot easily be done without a specific numerical tool. Such a tool is the constrained finite element method, which is perhaps the only method at the moment which can separate the behaviour modes, and which can be applied to a wide range of thin‐walled problems including members with holes. Separation is primarily performed by geometrical criteria, but further separation is possible on the basis of the stress components. In this paper one beam problem is presented and discussed. Critical loads and corresponding buckled shapes are calculated by allowing various pure and combined deformation modes. The calculations prove the practical advantage of the constrained finite element method.
Towards a demountable composite slab floor system
Authors: Gritsenko Alina , Nijgh Martin Paul , Veljkovic Milan 
Published: September 2019

ABSTRACTComposite slab consisting of in‐situ casted reinforced concrete on profiled sheeting, which is connected to steel beams by shear connectors, is a common structural flooring system in office buildings and car parks. The headed welded studs are inexpensive and rather easy to use in‐situ because they can be welded to the steel beam through the metal sheeting. A permanent link is created between the composite slab and steel beams leading to rather time‐consuming and expensive deconstruction process.Various types of bolted shear connections, recently investigated by various researchers in Europe, Australia, USA, provide a demountable alternative for the flooring system. This paper describes the experimental study using a bolted shear connector consisting of an embedded bolt/coupler and external bolt, originally developed for a prefabricated concrete deck.A full‐scale composite beam was tested under working loads up to 6.25kN/m2 in a 4‐point bending. In addition to bolted shear connectors a timber joist is embedded in the composite slab over the web of the steel beam. After the first life cycle, the timber joist provides the cut edge of the slab. The experiment is used to model behaviour in the first life cycle. The composite slab was then cut, demounted, re‐assembled and tested again in the second life cycle. The load was applied up to 6.25kN/m2 and finally to the failure. Multiple arrangements of shear connectors were investigated to analyse performance of “a modified composite slab”.Experience gained on the experiments of testing the composite beam in the first and the second life cycle is accompanied by FE analysis.
An experimentally validated study for open rib profiles steel‐concrete composite slabs behavior in partial connection
Authors: Soltanalipour Milad , Ferrer Miquel , Marimon Frederic 
Published: September 2019

ABSTRACTIn this paper the strength of steel deck‐concrete composite slabs is studied. Conventional slabs with open and dovetail profiles are studied with different designs, galvanized and stainless steel. Partial connection method (PCM) in Eurocode‐4 is permitted for slabs with ductile longitudinal shear behavior. Ductility, as explained in the clause 9.7.3(3), depends on the fact that the failure load exceeds the load corresponding to the slip (0.1 mm) in more than 10%; then the slab is classified as ductile. Apparently, the aim of this criterion is to ensure the slab can undergo further deflections until the whole yielding of the cross‐section is achieved, as required hypothesis by the PCM. The aim of this paper is to study the stresses developed at the cross‐section of composite slabs with open and dovetail profile, in order to evaluate the yielding degree of the cross‐section. Based on the results of this study, it is recommended to exclude open profiles from partial connection method (PCM), even if the slab is classified as ductile through Eurocode definition. Although all studied specimens are classified as ductile according to Eurocode‐4 clause 9.7.3(3), the observed stress distribution at cross‐section proves that yielding occurs in the slab with re‐entrant profile only, whereas slabs with open‐rib profiles remain almost elastic until their brittle failure.
Parametric study on non‐ductile demountable shear connectors
Authors: Odenbreit Christoph , Kozma András 
Published: September 2019

ABSTRACTThe basic principle of the circular economy is to reduce or totally eliminate waste and carbon dioxide production with the help of a multiple, efficient usage of resources. The application of reusable structural elements plays an important role and can contribute essentially to a low‐carbon future. Within the European research project REDUCE (Grant Agreement number: 710040), composite beams and steel‐based flooring systems, which are demountable and reusable, have been developed and investigated. The experimental investigations showed that the structural behaviour of the newly developed shear connectors differs from the behaviour of the traditionally applied welded studs. Some behave in a non‐ductile way.In order to assess, how far the regulations of EN1994‐1‐1 for shear connections can still be applied, parametric studies have been conducted. The respective numerical models were developed with the use of the commercially available finite element software ABAQUS® and were validated against the experimental observations. The effects of the lack of ductility of the shear connectors on the structural behaviour of the entire composite beam was examined with different types of shear connectors, shear connector layouts and material grades.This contribution presents the underlying laboratory tests as well as the results of the supplementing numerical parameter studies. The outcome provides valuable information for future design guidance concerning the use of demountable shear connectors in composite beams.
Resistance of the beam‐to‐column component “column web panel in shear” – numerical and analytical investigations
Authors: Corman Adrien , Jaspart Jean‐Pierre , Demonceau Jean‐François 
Published: September 2019

ABSTRACTThe « component method » is nowadays recognised by the European codes as the reference method to design and characterise steel and steel‐concrete composite joints. This method, which may be seen as a macroscopic application of the finite element method, consists in dividing the joint into a series of zones through which the forces are transferred, those zones being named “components”. Among them, the so‐called “column web panel in shear”, when activated and appropriately designed, can play a key role by providing a reserve of ductility to the joint. In Eurocode 3, Part 1‐8, a simple analytical model is proposed to predict the behaviour of this component in terms of stiffness and resistance. However, some recent researches have demonstrated that, in many cases, the so‐predicted resistance tends to be significantly overestimated, which turns out to be rather concerning from a safety point of view. In this context, the present paper will reflect first results of investigations conducted at Liège University on that problematic. In particular, beam‐to‐column welded joints have been studied in order to: (i) highlight the above‐mentioned problem through comparisons between existing experimental results and Eurocode 3 predictions, (ii) develop a sophisticated finite element model using the software Abaqus©, (iii) validate this FEM model using existing experimental results and (iv) develop an extensive parametric study in order to highlight the key parameters governing the resistance capacity of the studied component. Based on the conducted investigations, the final goal consists in providing a new analytical formulation which is able to predict more accurately the resistance of the column web panel in shear.
Mode‐based Beam and Connection Analysis of Frames
Authors: Hansen Anders Bau , Jönsson Jeppe 
Published: September 2019

ABSTRACTMajor steel structures are commonly constructed as frames or trusses. The connections between its beams and columns have a crucial influence on the global behaviour. However, a detailed assessment of the joints is often neglected with rough simplifications, which may lead to poor results. On the other hand, if performing a detailed assessment it is a time‐consuming task requiring special expertise. Consequently, the idea stressed in this paper is a novel approach on how to analyse thin‐walled steel frames including a detailed assessment of both the joint and beam mechanics.The approach is based on a transformation from standard degrees of freedom into a displacement‐based mode formulation. Furthermore, this transformation reduces the total number of degrees of freedom to be computed for advanced joints and beam elements. All this is achieved by adopting an advanced beam element formulation as well as introducing the idea of a ‘joint element’ formulated by finite shell elements. One of the main advantages of this idea is a general formulation of the joint, which makes it valid for many beam‐to‐column configurations. Furthermore, beam members can either be closed or open sections due to the adopted advanced generalised beam theory. Furthermore, a detailed analysis of the joint element itself is also achieved by this approach. Finally, an increased efficiency is achieved due to reduction of the total amount of degrees of freedom of the advanced model, and a new in‐depth knowledge of the joint behaviour is gained from this approach as well, due to the displacement‐based mode formulation.
Torsional Capacity of Slip Joints with Polygonal Hollow Sections
Authors: Bräutigam Katharina , Knoedel Peter , Ummenhofer Thomas 
Published: September 2019

ABSTRACTPolygonal steel sections are widely used for lighting towers and are more and more adopted for transmission line towers. They convince with an inconspicuous appearance compared to steel lattice towers. Therefore, instead of flange connections “invisible” joints are preferred, such as slip joints. The European design rules for overhead electrical lines (1) cover the use of these joints very generally by a constant ratio of the overlapping length L and the section's diameter D. It is neither distinguished between load conditions nor between cross‐sectional shapes. The ratio value L/D = 1.5 is based on bending tests without regard to torsional moments. In the design of transmission line pylons, torsional loading occurs in the load case of a single‐side loss of a transmission line. Thus, there is a need to improve the knowledge on the load bearing effect of a slip joint connection within this special load case.In this paper the torsional capacity of slip joints is investigated to identify the capability of polygonal cross sections to carry this additional load, particularly in comparison with circular hollow sections. On the basis of numerical and analytical analysis, an adaption for the design of the slip joints is proposed.
Study of the Rigidity of a Concentrically Braced Frame Connection Using End Plates
Authors: PARENT Serge , ROY Nathalie , GAUTHIER David 
Published: September 2019

ABSTRACTIn steel buildings, concentric braced frames are often used as lateral force resisting systems. In this type of systems, the connection between the beam‐gusset connection and the column may consist of end plates or double‐angle sections. Connection design with double angles is simple and well documented, but it requires the handling of many steel angles. On the other hand, single continuous end plate connection design is based on the use of a single plate, easily produced in the shop leading to a lesser risk of manufacturing errors. The purpose of this research project is to characterize the behaviour and stiffness of three types of connections used in a concentrically loaded braced frame: a standard double angle connection (DAC), a continuous end plate connection only welded to the web of the beam (EPW), and a continuous end plate connection welded all around to perimeter of the beam (EPF). The results of nine full scale samples are presented. These results use a HSS127×127x4.8 brace connected to a W310×45 or W460×52 beam. The beam‐gusset assembly connects to the web or to the flange of a W250×73 column. The connections are subjected to a progressive cyclic loading until failure in a full‐scale assembly in the laboratory. The preliminary results make it possible to characterize and compare the three types of connections attached to the web/flange of the column. In conclusion, the three connections have different stiffness factors. The EPF connection is the most rigid, followed by the DAC connection and finally the EPW connection.
Validation of simple superelement model of warping transfer in moment connections of portal frames
Authors: Vaszilievits‐Sömjén Bálint , Szalai József , Rad Majid Mohavedi 
Published: September 2019

ABSTRACTA simple beam element‐based modelling technique has been developed to allow the analytic definition of a stiffness matrix to describe the behavior of corner region between two doubly symmetric thin‐walled I beams connected through moment connection. The stiffness matrix describes the relation between „out‐of‐plane” type deformations of connected beam ends and related internal forces including shear force parallel to the flanges, torsion, weak axis bending and warping of flanges. The model allows to simulate the warping and distortion of the beams within the connection region. The resulting stiffness matrix is compatible with the thin walled beam theory with 7DOF beam elements. A parametric study has been performed to validate the model with shell element‐based simulation, using Abaqus and ConSteel software, concentrating on the direct out‐of‐plane behavior of portal frames. In the validation process first and second order analysis results and results of linear buckling analysis have been analyzed. The correctness of the shell element‐based simulation has been proved by full‐scale laboratory test. The test result has shown excellent agreement with the numerical simulation and with the proposed model.