bluuebunny/crossref_metadata_2025 huggingface dataset:
11.25: Rocking damage‐free steel column base with friction devices: Design procedure and global seismic response of buildings
Authors: Freddi Fabio , Dimopoulos Christoforos A. , Karavasilis Theodore L.
Published: September 2017

Resilient minimal‐damage steel frames, such as post‐tensioned self‐centering steel frames or steel frames with passive dampers, have been extensively studied but little attention has been paid to their column bases. This paper presents a rocking damage‐free steel column base using post‐tensioned high strength steel bars to control rocking behavior and friction devices that provide stable energy dissipation capacity. Contrary to conventional steel column bases, the monotonic and cyclic hysteretic moment‐rotation behavior of the proposed column base can be easily described using simple analytical equations. The paper describes in detail a step‐by‐step design procedure for the column base that ensures damage‐free behavior and adequate self‐centering and energy dissipation capacity. A finite element model for the column base is developed in OpenSees and used to conduct nonlinear dynamic (seismic) analyses of a building using self‐centering steel moment‐resisting frames. The results of the analyses show that the column base helps the building to avoid damage in the 1st story columns along with eliminating the 1st story residual drifts under both the design and maximum considered earthquake intensities.
11.29: Updates to the ASCE‐41‐13 provisions for the nonlinear modeling of steel wide‐flange columns for performance‐based earthquake engineering
Authors: Hartloper Alexander , Lignos Dimitrios
Published: September 2017

Performance‐based earthquake engineering requires numerical models that are able to reliably predict the expected component behavior of buildings under seismic excitations. The nonlinear modeling guidelines provided in ASCE‐41‐13 have historically been used in this context by practicing engineers. However, for steel wide‐flange columns, the recommendations are primarily based on experimental data that was fairly limited until recently. This paper addresses many of the limitations present in ASCE‐41‐13 for the modeling of steel wide‐flange columns. Recent experimental data from large‐ and full‐scale tests on wide‐flange steel columns, supplemented with detailed finite element studies, has been collected for a wide range of column cross‐sections and applied compressive axial loads. Multiple regression analysis is utilized to develop multivariate predictive equations for the seismic response of steel wide‐flange columns. It is found that the primary contributors that dominate the column response are the local web slenderness, member slenderness and the applied axial load ratio due to gravity loading. Guidelines for developing nonlinear component models for steel columns that can be directly used in both nonlinear static and dynamic analysis procedures are provided. The predicted responses are validated against test data that was not part of the original database. Furthermore, recommendations are proposed for modeling wide‐flange columns subjected to varying axial loads as well as bidirectional loading; and a new limit for force‐controlled elements is proposed for columns under high axial compressive loading and lateral drift demands.
11.40: Cyclic bending of multi‐stiffened plate girders: Numerical model development and analysis
Authors: Dib Abdelkarim , Vigh László Gergely
Published: September 2017

Ductile design of steel structures subjected to seismic effects requires creation of dissipative zones. In case of moment resisting frames and eccentrically braced frames, in order to achieve high ductility this requirement often yields to the application of compact sections in the dissipative zone, otherwise premature local plate buckling will govern the design and high ductility cannot be obtained.

Buckling resistance of thin web plates of I girder can be significantly increased by application of stiffeners in the web. Vertical stiffeners are often required in seismic links of eccentrically braced frames, but rarely used in moment resisting frames. Application of longitudinal stiffeners is common in bridge structures only. Such stiffeners are typically designed as relatively stiff and strong stiffener, that is characterized by column‐type buckling behaviour, resulting in relatively low ductility.

This paper introduces an innovative structural solution: using flexible (i.e. with low rigidity relative to the plate rigidity) multiple longitudinal stiffeners enables plate‐like overall buckling behaviour, which is beneficial with respect to ductility. Although the behaviour of such stiffened plates subjected to monotonic loading is studied in several researches, there is no data available on the cyclic ductility.

To study the cyclic behaviour and ductility of such girders, numerical and experimental programme is worked out. This paper primarily focuses on the numerical model development. Shell element numerical model is developed for non‐linear static analysis of the monotonic and cyclic loading. The model is validated by the test results. The developed and verified model is being applied for parametric analysis to study the cyclic performance of various configurations.
11.45: Cyclic testing on hybrid buckling‐restrained Braces (HBRBs)
Authors: Pandikkadavath Muhmaed Safeer , Sahoo Dipti Ranjan
Published: September 2017

Buckling‐restrained braced frames (BRBFs) are dependable lateral load‐resisting systems to safeguard buildings against seismic actions. Nearly‐symmetric and stable hysteretic response of buckling‐restrained braces (BRBs) stimulated the wide spread incorporation of BRBFs in various structural systems. However, BRBFs suffer from increased drift demands as compared to other braced frame systems, mainly due to the low post‐yield strength/stiffness of BRBs. This study proposes a hybrid buckling‐restrained brace (HBRB) combining the short yielding core BRB (SBRB) and a heavy elastic hollow steel section (HSS) in series. SBRB is allowed to undergo desired level of plastic deformation, whereas the elastic HSS segment can provide the improved stiffness to the HBRBs. Such HBRBs have similar, stable and balanced hysteresis and enhanced elastic and post elastic stiffness as compared to conventional BRBs. In this study, three reduced‐scale models of proposed HBRBs with varying yielding lengths are fabricated and sub‐assemblage tests are carried out under modified non‐linear reversed cyclic loading conditions. For the buckling‐restraining of SBRB segments, concrete filled detachable casings with all‐around end cover plate arrangement is used, whereas a rigid connection between the SBRB and HSS is considered. Results showed that HBRBs were capable of withstanding an axial core strain of more than 6% without any instabilities. Further, HBRBs exhibited excellent hysteric response, load‐resisting capacity, deformation ductility, and hysteretic energy dissipation potential. Strength‐adjustment factors of HBRBs are also found to be little larger than those of conventional BRBs.
11.51: Numerical investigation of short seismic links in shear
Authors: Bulic Mladen , Causevic Mehmed
Published: September 2017

It is well known that seismic links are usually designed to remain in elastic region during ordinary loading but withstand nonlinear deformation during seismic event having capability to dissipate seismic energy. The use of short seismic links is recommended because they are capable of dissipating seismic energy in larger quantity by shear, while the webs in these links are expected to yield in shear during large seismic events, i.e. dissipation of seismic energy by bending in links is negligible. Shear deformations are basically plane deformations of the cross section web of the link, without any significant tendency towards lateral torsional buckling. To achieve the required plastic rotation, local instabilities such as flange or web buckling should be delayed. The flange local buckling is delayed by specifying width to thickness ratio, while the web local buckling will be prevented by adding number of transverse stiffeners along the web of the link. The main purpose of the stiffeners is to preserve buckling of the seismic link web, i.e. to achieve plastification of the cross section by shear. Dissipation of energy in the stiffened link will occur sooner through inelastic shear deformations than through inelastic web buckling. The seismic links were chosen having the same cross section and the same length, but with different number of stiffeners, i.e. with three couples of stiffeners, two, one and without any stiffener respectively. A finite element modelling approach in investigating the structural behaviour of short links is presented. Both the material and geometric nonlinearities are considered in the FE modelling using the software ABAQUS and the Shear force – Displacement relationships was obtained. The FEA results are validated against the test results and the comparisons indicated that the FE analysis procedures agree well with the test results.
11.55: Development of a 2‐dof model simulating the dynamic response of special truss moment frames with shape memory alloy bars as dissipation devices in the special segment
Authors: Ntina Maria , Sophianopoulos Dimitrios , Tsopelas Panos
Published: September 2017

The Special Truss Moment Frame (STMF) is a seismic load‐resisting system that consists of trusses as horizontal members and specially designed segments that are expected to withstand large cyclic deformation during seismic events. The initial concept [1–3] was based on designing a special segment inside the truss as a fuse to dissipate the input energy in a ductile manner, while the other members outside the special segment stay in the elastic range. Later on, special dissipation devices in the aforementioned segment were incorporated [4], and the results obtained showed an adequate performance of the STMF. In view of the above, the present work aims to develop a simplified structural model of a STMF, with shape memory alloy bars as dissipation devices in the special segment. After developing a more sophisticated constitutive model of these bars, a 2‐degrees‐of‐freedom simulation is proposed, in order to initially capture the dynamics of the STMF in a satisfactory manner. This model has two degrees of freedom, one translational and one rotational, accounting for simplified assumptions regarding the elastic response of the STMF columns and truss outside the special segment. After fully exploring the deformation features of the model, the equations of motion are formulated. Results obtained under various simple as well as complex excitation patterns showed that the model at hand may be used as basis for on‐going research.
I.11.39: Behaviour factor evaluation of moment resisting frames having dissipative elements
Authors: Alavi Amin , Castiglioni Carlo Andrea , Brambilla Giovanni
Published: September 2017

Civil structures subjected to strong earthquakes need to dissipate large amounts of energy. Hence, the conventional systems suffer significant inelastic deformations (costly damages) in main structural elements (steel beams, columns and concrete slabs) and residual interstorey drifts after a strong seismic event. Repair work, however, in these cases is most of the time not feasible, or too expensive. FUSEIS Bolted Beam splices, therefore, can be installed in buildings in order to protect the structural elements during the seismic events. On the other hand, behaviour factor in EC8 is provided only for conventional frames such as MRFs, CBFs, EBFs and so on without any clear specification for other types of structures i.e. innovative dissipative structures. This paper investigates the seismic performance of buildings having FUSEIS bolted beam splices by means of non‐linear static analysis, results also compared with conventional frames. Behaviour factor of these buildings are then evaluated based on single degree of freedom systems. This paper investigates one of the several possibility of the calculation of the behaviour factor based on SDFS. The other possible methods will be deeply study in the upcoming paper. In order to do so, three buildings regular in and elevation has been deeply investigated as case studies. Numerical results highlight that plastic deformation concentrates mainly in the beam splices, hence, remaining the main elements in elastic region and hence protecting them from any sort of damages.
12.04: Experimental and numerical investigation on the Q690 high strength steel slender columns of welded H‐sections under compression
Authors: Ma Tian‐Yu , Li Guo‐Qiang , Chung Kwok‐Fai
Published: September 2017

This paper presents the experimental and numerical findings on Q690‐QT high strength steel welded H‐sections. A total of seven slender columns under axial compression were successfully carried out. Four sections of different sectional dimensions were involved. Before testing, the initial out‐of‐straightness of all the specimens were measured. All the tests were conducted in a 1,000 tons universal servo‐controlled testing machine. During the test, displacement transducers were used to record lateral deflections at the mid‐height section and axial deformations at the top ends of all the specimens. Strain gauges were mounted onto the outer surface of the flanges at three sections of each specimen. The strain gauge readings were used to calculate the loading eccentricities at both ends of the columns. All the columns were failed by overall buckling about the minor axes of their cross‐sections and neither weld nor material fracture was found. Separate specimens were fabricated for the measurement of residual stresses of all the sections. The numerical simulation on these tests are also reported. The numerical models were based on the measured geometrical dimensions and material properties of all the specimens. The measured out‐of‐straightness, loading eccentricities, and residual stress patterns were also introduced in the models. These numerical models were proved able to simulate the behaviour for all the test specimen except one, in which the end rotational restraints were significant. Both the test result and the numerical result with normalized initial out‐of‐straightness were compared with the current design codes. It is preliminarily proposed that column buckling curve a in the current design codes may be appropriate for the design of Q690 high strength steel welded H‐sections. And this proposal is need to be confirmed by complementary parametric study in the future.
13.18: Advanced analysis of braced steel frames: Modelling accounting for the post‐limit behaviour of compressed angle braces
Authors: Giżejowski Marian Antoni , Barszcz Anna Maria
Published: September 2017

This paper presents a method of advanced analysis applied to steel plane load bearing systems like trusses as well as unbraced and braced frames. The effects of both material and geometrical nonlinearities on the structural behaviour are studied together with tracing the whole range of truss member behaviour. In the braced frameworks, the truss bracing model accounts for the effect of post‐limit behaviour on the inelastic redistribution of forces in frame members. Details of finite element incremental stiffness matrices for frame members and truss bracing members are briefly presented and followed by the discussion how the effects of gradual yielding, buckling and semi‐rigid joints are included. The implementation into engineering computer software is summarized and followed by certain aspects of truss and frame structural systems design according to Eurocode 3. A simple two‐bar arch truss sensitive to the elastic snap‐through buckling for which the closed form solution exists is considered as an example. Simulations of the behaviour of this truss show how the nonlinear behaviour of a single member affects the global instability of the truss. Conclusions are formulated with reference to the application of advanced analysis in direct design of steel braced frameworks.
14.01: Influence of beam‐to‐column joints on the robustness of earthquake‐resistant moment‐resistant frames
Authors: Francavilla Antonella B. , Latour Massimo , Rizzano Gianvittorio , Demonceau Jean‐François , Jaspart Jean‐Pierre
Published: September 2017

Robustness of Moment Resistant Frames (MRFs) designed according to current seismic codes and subjected to a loss‐of‐column scenario is strictly linked to the deformation capacity of beam‐to‐column connections, which are usually subjected to combined axial and bending loads. In the seismic design of steel frames, once avoided the yielding of columns, a global dissipative collapse mechanism has to be ensured by imposing the formation of plastic hinges at the ends of the beams or in the connections and guarantying, provided that the elements involved in plastic range have an adequate energy dissipation capacity. Within this framework, the aim of this paper is to analyse the influence of the response of the connections designed for seismic application on the global behaviour of MRFs under a loss‐of‐column scenario providing an accurate modelling of connections subjected to combined axial and bending loads. To this scope four different beam‐to‐column joints designed for seismic actions, previously tested under cyclic load history at the STRENGTH laboratory of Salerno University, have been modelled and introduced in a case‐study structure, whose response has been assessed by means of push‐down analyses. The performances of the analysed frames have been analysed and is compared using the Residual Reserve Strength Ratio (RRSR) index combined with the energy balance method.
15.02: Direct analysis of steel frames with non‐prismatic sections via tapered beam‐column elements
Authors: BAI Rui , LIU Si‐Wei , CHAN Siu‐Lai
Published: September 2017

Members with tapered sections are popularly used in contemporary structures for architectonic appearance, besides that, this is in the most optimal, economic and effective manner to use material to the actual requirement according to the section strength along the member length. This paper proposes a new design approach based on direct analysis method for steel frames with tapered sections, where the structural behaviours of members are accurately simulated via sophisticated non‐prismatic beam‐column elements with analytical formulations. Conventional method uses approximated assumptions for section properties along the member length, causing unreliable estimations on member stiffness and strength and usually bringing over‐conservative design results. To this, this research analytically expresses the flexural rigidity and sectional area for the stiffness and mass matrixes of an element, respectively. In order to directly reflect column buckling effects on the proposed element, a generalized imperfection shape‐function for tapered section is developed, where the imperfection shape function is expressed highly fitting the 1st Eigen‐buckling mode shape. Examples are employed to validate and verify the reliability, efficiency and accuracy of the proposed elements. The current research is believed to be a great contribution to the modern design of non‐prismatic members.
16.20: Influence of bearing length on the patch loading resistance of multiple longitudinally stiffened webs
Authors: Loaiza Nelson , Graciano Carlos , Chacón Rolando , Casanova Euro
Published: September 2017

Incremental launching is one of the common steel bridge assembly methods used nowadays, its practical application consists in passing the bridge assembly through the launching shoes as well as over each support pile. In some cases, when plate girders are used, it is usual to find longitudinal stiffeners reinforcement in order to prevent web local buckling produced by the vertical reaction acting in the support pile. A considerable number of studies have focused on evaluating the impact of a single stiffener on the resistance of plate girder subjected to patch loading. However, the effect of multiple longitudinal stiffened plate girders subjected to lengthy compressive load has received little attention.

Therefore, this paper aims at studying the influence of load bearing length on the ultimate strength of multiple longitudinally stiffened webs subjected to compressive loads. Patch loading resistance is numerically calculated using a previously validated nonlinear finite element analysis. Subsequently, a parametrical study is conducted to investigate the effect of the aforementioned load length and the relative position and size of the stiffeners on the ultimate strength.
16.25: Hot‐dip galvanized composite dowel strips in bridge construction: The combination of two advantageous developments
Authors: Ungermann Dieter , Holtkamp Svenja , Feldmann Markus , Kühne Ronny , Rademacher Dennis
Published: September 2017

Comprehensive research during the last years showed that hot‐dip galvanizing of steel members in bridge structures allows significant economic and ecological advantages. It could be demonstrated that the first corrosion protection can last over a bridge's lifetime of 100 years, even in an environment with a high corrosivity, so that no major maintenance measures of the corrosion protection are necessary.

Parallel to this research, another innovative solution to increase the efficiency of composite bridges has been developed. Starting with several research projects and a first application in 2003, composite dowel strips offer a very economical solution for shear connections between steel girder and concrete slab in composite bridge constructions. Continuous improvement and further development finally led to a general technical approval by DIBt in Germany. Many bridges containing this new technology are built since then, not only in Germany. However hot‐dip galvanizing may not be applied to bridges with composite dowel strips as the effects of the hot‐dip galvanizing on the fatigue resistance of flame cut composite dowel strips are unknown. Therefore, the necessary fatigue check according to EC 3‐1‐9 [2] can currently not be carried out properly.

A new research project was launched by the Institutes of Steel Construction of RWTH Aachen University and TU Dortmund University [4], with the aim to analyse the fatigue behaviour of hot‐dip galvanized composite dowel strips. Furthermore a simplified evidence of absence of cracks according to DASt‐Guideline 022 [5] shall be performable by defining a detail class for composite dowel strips. The research work includes extensive experimental and numerical studies on the influences during hot‐dip galvanizing and on the fatigue behaviour of galvanized dowel strips. First results of these studies will be presented in this paper as well as the experiences of a first bridge project with hot‐dip galvanized composite dowel strips in Germany.
18.02: Optimisation of masts and towers
Authors: Støttrup‐Andersen Ulrik , Nielsen Mogens Gunhard , Laursen Thomas Brink
Published: September 2017

Within the last decades the need for tall structures has accelerated with the requirements for effective communication especially the advent of radio, radar and television. Latest the exponential growth in the use of cellular phones has meant a new era for towers and masts.

There are many challenges for the engineers associated with these tall and slender structures especially when it concerns guyed masts. Many experts have stated that “a guyed mast is one of the most complicated structures an engineer may be faced with”. This statement is unfortunately underlined by the fact that the number of collapses of masts is relatively far greater than for other types of structures.

The overall layout of telecommunication masts and towers is governed by the requirements to the transmission and receiving conditions. Added hereto the access and working conditions for installation and service are important issues for the design.

A total optimising of towers and masts to the functional, economical and environmental requirements is a job for specialists, and it should normally take into account the total lifetime of the structure. However the optimising is often only focused on minimising the direct costs for the establishment of the structure, neglecting the many other factors influencing the “correct” optimisation.

The extensive increase in the number of new masts and towers in the last few years, especially due to the expansion in the cellular telephones, has resulted in increased concern of the aesthetic appearance of these structures and this is an additional challenge to the designers.

This paper gives an introduction to the optimisation of these structures and examples of designs are presented.
18.04: Experimental investigations of members from angle sections
Authors: Spiliopoulos Andreas , Dasiou Maria‐Eleni , Vayas Ioannis
Published: September 2017

Angle sections are commonly used in many Civil Engineering applications and especially in lattice towers for telecommunication purposes. Nevertheless, due to their geometrical characteristics, design expressions, as for example those included in EN1993‐1‐1 or EN 1993‐3‐1, do not apply for cross sections or members composed of angle sections. Although a number of numerical investigations for cross section strength and member stability and proposals for relevant design expressions exist, only limited experimental investigations on members from angle sections, mostly on cold‐formed ones, can be found in literature.

In the current paper a test campaign on members from equal leg hot rolled angle sections that has been carried out at the Institute of Steel Structures of the National Technical University of Athens (NTUA) is presented. Tests included eight 3‐point bending tests and thirty‐one buckling tests on columns subjected to concentric and eccentric compression. The aim of the research is to use the experimental data for calibration of numerical models, the investigation of possible inelastic reserves for angles that were detected in analytical models and as reference for the development of new design expressions oriented towards angle sections only.
01.04: Joints between open section beams and tubular columns: New configuration for semi‐rigid and moment resistant bolted joints
Authors: Vicente Guiomar , Simões Rui , Rebelo Carlos
Published: September 2017

The appealing shape and the mechanical properties of the tubular members are the main responsible for their growing popularity amongst architects and engineers. However, their potential hasn't been properly explored due difficulties encountered in the joints conception and design, with special emphasis on the bolted joints if rigid and/or full strength behaviour is required for the joint.

Currently, in the European regulation scenario, the guidance for the joints design is given in the EN 1993‐1‐8. The recommendations for joints with tubular members are given in its seventh chapter, where only welded solutions are considered. Bolted solutions aren't referred, and no guidance is given to predict the joints rotational stiffness and rotation capacity. However, a window is left open in the standard sixth chapter with the given method to predict the joints structural properties (component method). The method is applicable to joints in frames of any type, independently of its configuration and of the joined members’ sections. Once known the nonlinear response of each joint basic component, commonly represented by force‐displacement curves, the component method can be used to predict the joint structural properties.

Regarding the current lack of information in this subject, the authors propose a new configuration for joints connecting open section beams to rectangular or square hollow section columns. The configuration was conceived with the double purpose of getting a joint with bending moment resistance capacity and with high initial rotational stiffness. Furthermore, looking on the current regulation scenario, it would be desirable that joints with the proposed configuration could be designed by the component method. Thus, the authors identified the joint active basic components, and are developing experimental work in the sense of establish the force‐displacement curves which represent the nonlinear response of the new basic components. The experimental work, already developed, on the basic components structural response is here summarily presented.
19.05: CLT‐steel composite slimfloor construction: An investigation of mechanical behaviour using finite element software
Authors: Okutu Kwesi , Davison Buick , Carr Jon
Published: September 2017

A new method of constructing multi‐storey buildings has been investigated using Cross‐Laminated Timber (CLT) panels acting as floor slabs with a steel framed support structure. Conventionally, concrete slabs are used for floor systems but timber panels weigh approximately one third of the equivalent concrete slabs, and hence the superstructure mass is significantly reduced, smaller sections can be used and thus less steel is needed overall. Further economy can be gained if composite action that can be generated between the CLT flooring and supporting steel beams. This paper presents the findings of a detailed finite element study to examine the composite performance of steel‐CLT beams taking into account the method and degree of shear interaction, the determination of a suitable effective to width to account for shear lag, the position of the CLT relative to the beam (i.e. above the beam as in conventional composite construction or within the beam depth to form a slimfloor type system) and the layup and orientation of the laminations in the floor units. After briefly outlining the advantages of using a CLT‐steel hybrid system, this paper explains how a detailed numerical model which captures the key features of the system was developed and validated and then present the results of a parametric investigation into the generation of composite action in a CLT‐steel hybrid system.
19.10: Hyperbolic paraboloid shape shell structure: As roof for an outdoor music stage
Authors: Simoni Thomas , Nordestgaard Peter Madsen
Published: September 2017

This paper concerns the design, calculations and construction of a hyperbolic paraboloid steel shell structure used as a roof for an outdoor music stage. The structure was calculated using FEM analysis and constructed using standard steel trusses and trapezoidal steel plates. The steel structure is lined with wood and covered with roofing felt.
21.02: Strengthening of orthotropic steel decks using UHPC: UHPC‐concrete instead of asphalt layer for additional at least 50 years in service
Authors: Unterweger Harald , Novak Friedrich
Published: September 2017

Orthotropic steel bridge decks for slender and long spanned girder bridges were frequently built in the 60ties and 70ties of the last century in Europe. In the design of such bridge decks only the ultimate load carrying capacity was considered, without fatigue aspects. Due to the dramatic increase of heavy traffic in the European road network, sometimes the calculated remaining fatigue life is exhausted, after only 50 years of service life.

In the paper the relevant results of a research project are presented, with the challenging aim to increase the service life of such orthotropic bridge decks to at least 50 years after strengthening. The research activities were based on a very slender orthotropic deck, with a slenderness of elr/tdp = 36 for the deck plate. Two significant details for fatigue of such a representative bridge deck have been analysed. Detail D1 represents the welded connection of the longitudinal rib to the deck plate and Detail D2 is the welded connection of the longitudinal rib to the cross girder. Extensive numerical studies were done for the strengthening solution with an UHPC‐concrete layer. First the present remaining service life was calculated using a finite element model of the steel deck. The beneficial effect of the asphalt layer is considered by an increased wheel contact area. The current fatigue load model FLM‐4 from the Eurocode with 5 lorry types and 3 different axle types was executed and the gross weight of each lorry type was adapted to weigh in motion measurements at an Austrian highway bridge. For determining the stress reduction factors in the details D1 and D2 after strengthening the finite element model had to be extended with the UHPC‐concrete layer. The concrete cracking was conservatively considered with an effective Young modulus Ec,eff = Ec/4. For both details at least 50 years in service can be guaranteed with an UHPC‐pavement that has a thickness of 80mm. Based on these studies full scale tests on an orthotropic deck specimen were done, including overload effects (increased axle loads) and severe temperature effects (simulation of a cold rain event on a very hot summer day) to stimulate concrete cracking. The full scale tests together with the numerical studies showed very good results with regard to the remaining fatigue life. Therefore in the near future a prototype application on an Austrian highway bridge is intended.
21.03: Reusability indicator for steel‐framed buildings and application for an industrial hall
Authors: Hradil Petr , Talja Asko , Ungureanu Viorel , Koukkari Heli , Fülöp Ludovic
Published: September 2017

This paper introduces a new method for the assessment of reusability of components and structures of steel‐framed buildings. It enables classification of various building parts and products through a procedure to calculate, weight and aggregate recyclability indicators and thus it helps to explore their potential to a second life. In connection with life cycle analysis (LCA), such an indicator provides valuable information for the Module D of the European standard EN 15804 and the Environmental Product Declarations.

The method is applied on an existing typical industrial hall structure. Five different end‐of‐life scenarios were investigated for selected components, including recycling of the material as scrap, but also the careful deconstruction with components prepared for future reuse after cleaning, sorting, inspection and packaging. As an example, both cost and environmental burdens are compared in the life‐cycle study of a selected girder.

The results clearly show the significant reduction of environmental impacts achieved with reuse. However, we conclude that the reuse processes could be made more competitive with further reduction of life cycle costs. The higher reuse costs originate from the quality checks, manual work during deconstruction, storage and long transport distances. Adoption of cost effective deconstruction, sorting and inspection technologies can significantly improve the economic benefits in the studied reuse scenarios.
21.06: Seismic retrofit of historical earthen buildings using steel
Authors: Reyes Juan C. , Yamin Luis E. , Gonzalez Cristian D. , Sandoval Juan David
Published: September 2017

This article is not available for publication.
22.03: Acoustic ceiling designed for trains passing at 250km/h: Holmestrand – The first station in the world inside a mountain entrance hall
Authors: Karlsson Stefan , Eidet Espen , Holmstrøm Peter , Kærn Jens Christian
Published: September 2017

The Holmestrand station will be located inside a rock cavern, with two separate tracks for platforms and two tracks for through trains in the same hall. Hence the entrance hall will be designed to allow high speed trains to pass at 250 km/hour, creating challenges concerning pressure, fatigue, wind speed and noise levels within the station hall.

The steel structure comprises of a suspended ceiling inside the station of more than 12,000 m2. The ceiling shall prevent drip from the rock and act as an acoustic silencer. In addition, great emphasis has been placed on the architectural configuration. The primary steel is designed for a life time of 100 year.

The ceiling is divided into 3 parts, one above each platform and one above the tracks.

Main beams and cross beams form a grid that is suspended from the mountain by individual hangers of adjustable lengths. On top of this grid a corrugated aluminium plate prevents drip from the rock, and below this grid acoustic panel is fitted to reduce noise problems. All steel between the rock surface and the corrugated plate on top of the ceiling consists of duplex steel. Below the corrugated steel plate the main and cross beams are hot dip galvanized (HDG) to minimum 200 μm and the acoustic panels are sandwich elements with perforated steel surface. All joint connections are bolted and most of them with preloaded stainless steel bolts. There are many friction grip connections that lead to testing prior to assembly of the preloaded stainless steel bolts and the friction surfaces for the different material combinations.

In addition to duplex steel, HDG steel and aluminium the ceiling above the platforms is also supported by weathering steel for architectural reasons. Thus the detailing required special attention in order to secure the required service life without accelerated corrosion from either galvanic effects as combination of different materials are used or the detailing of e.g. weathering steel.

The new 14 km double track through the town of Holmestrand will greatly improve the rail services on the Vestfold line. Rambøll is responsible for designing 7 km of this line. Total Cost: NOK 6.6 billion.

The work for Rambøll started in 2010 and the station opened on November 27, 2016
22.04: New design for transmission line towers in Denmark
Authors: Gludsted Martin , Nielsen Mogens G. , Skouboe Henrik , Steenholt‐Eliasson Karl Emil
Published: September 2017

In these years, Europe puts a great effort into reducing the CO2 emission. Consequently, a more flexible and strong electricity transmission grid is needed, to be able to carry power from e.g. the offshore wind farms to consumers. Furthermore, the grid must be able to reach international markets.

The tendency of the public opinion reacting against new power transmission lines is not only a Danish phenomenon, and various design competitions on overhead transmission line towers have been going on recently in Europe.

The Danish TSO Energinet.dk has recently replaced a 174 km overhead transmission line in Jutland with a new overhead line, contributing to the Danish effort to reduce the CO2 emission. The line is the backbone of the grid with a transmission capacity that has been increased 3 times.

Overhead transmission lines have a great impact on the landscape which is why much effort has now been put into creating a new design that minimizes the visual impact on the landscape in order to obtain public acceptance for the new line.

The transmission line consists of new design towers, made as steel pole structures. The tower design is shorter and leaner than traditional lattice towers for better aesthetics, less environmental impact, and a shorter installation process due to the monopile foundation.

The use of steel and alternative design has made it possible to obtain the aesthetic and functional goal: To minimise the visual impact on the surrounding landscape while also providing a resistant and durable solution.

The total costs of the structures have been optimised by using steel monopiles for foundations. This has increased the speed of the rollout and decreased the impact on the surroundings and the costs of installation.

The outstanding architectural design has been done by Bystrup Architects. Ramboll has done the detailed structural design for Energinet.dk.

Energinet.dk is currently designing new overhead transmission lines for Denmark together with Bystrup Architects and Ramboll. During the design process, the design is being optimised with respect to aesthetics, the structural and the foundation requirements.
P03.01: The influence of the connections between concrete and steel on the joints modelling
Authors: Campian Cristina , Pop Maria , Chira Nicolae
Published: September 2017

The paper analyses the behaviour of two types of beam – column connections that consists of steel welded joints and composite beams to steel columns joints. The connection under were simulated with a three‐dimensional numerical model using finite element analysis (FEM) by using the commercial package program Abaqus v.6.11.

The behavior of the studied connections are represented in terms of moment – rotation relationship. The initial stiffness, rotation capacity and the ultimate moment capacity are showed. The effects of the distribution of the forces and also the internal moments, and also the deformation capacity from a frame are taken into consideration.

The behavior of the studied connections are represented in terms of moment – rotation relationship. The initial stiffness, rotation capacity and the ultimate moment capacity are showed. The effects of the distribution of the forces and also the internal moments, and also the deformation capacity from a frame are taken into consideration.

Based on the results of the joints models approached in the finite element program are extracted to compare the joints in term of moment capacity and ultimate rotation under hogging moments, and thus the entire moment–rotation to each joint configuration.

Finally, the composite connection's behavior is discussed in detail, conclusions and some recommendation are presented.
P04.01: Failures of stiffened ducts stressed by temperature
Authors: Dolejš Jakub , Pošta Radek
Published: September 2017

Steel pipelines are an important part of industrial technology equipment in many sectors. Ducts with a ratio of pipe diameter to wall thickness of up to 150 are generally considered as simple beams, ducts with a higher ratio have to be considered as shell elements. Technical literature provides a number of methods for designing such structures stressed by various kinds of loads. Failures that have occurred in recent past suggest that the existing common design method for industrial piping shows some insufficiencies. This paper is focused on the study of stiffened steel shells stressed by temperature changes. Due to a high temperature load, there is a big temperature deformation of the whole system. This deformation caused by temperature differs within particular parts of the system. As the high temperature source is inside the pipe, the highest temperature is on the inner surface of the shell. The variation of the temperature in the shell and the partial warming of the ring stiffener is caused by heat conduction. Due to the different temperatures of the surrounding environment the stiffener is always colder compared to the shell. The research is focused on the shell behaviour close to the ring stiffener, which represents the area most tending to cracks initiation and their expansion due to the low‐cycle fatigue phenomenon. The research procedure consists of several sub‐parts. In the first part, the authors focus on determining the thermal load based on the theory of heat transfer. The resulting heat transfer coefficients were verified by measurements performed on the real structure. These findings served as boundary conditions for numerical modelling in Ansys. The resulting values of strain and stress were one of the inputs for the subsequent analysis of lifetime prediction from the viewpoint of low cycle fatigue. The number of cycles to failure (creation of macro‐cracks) for various types of structural solutions has been determined in the final part of research.
01.25: The influence of end–plate joints stiffening on the rotation capacity
Authors: Ostrowski Krzysztof , Kozłowski Aleksander
Published: September 2017

The methodology for the rotation capacity determination of the end‐plate beam to column connections using statistical methods has been presented in the paper. Especially, the influence of stiffeners on the rotation capacity of the joints was studied. Additionally, the assessment of the joint behaviour without stiffeners was conducted. The analysis was carried out on the basis of the numerical experiment plan in which five basic variable factors were examined: the height of the beam profile (profile HEA, hb = 290 ÷ 490 mm), the height of the column profile (profile HEB, hc = 300 ÷ 500 mm), the thickness of the end‐plate (tp = 10 ÷20 mm), the distance from the upper flange to the axis of the bolts (cg1 = 60 ÷ 120 mm), the horizontal spacing between the bolts (w = 135 ÷ 200 mm). The response surface of rotation angle was obtained with the use of FEM analysis (ANSYS software) on the basis of the Hartley's numerical experiment plan (PS/DS‐P:Ha5).

This paper presents the methodology for flush end‐plate connection shaping and requirements, which should be introduced to the models for numerical calculations, when the analysis is conducted for objects subjected to large deformations. Material characteristics and geometrical properties were determined on the basis of the Multistage Hierarchical Validation of FEM models. The study was performed for the steel S235 and for the bolts grade 10.9 (ISO 4014).
01.28: Modelling of bolted connections by the finite element method
Authors: Vilela Paula Moura Leite , Carvalho Hermes , Queiroz Gílson
Published: September 2017

This paper presents the modelling of a complete bolted connection based on a model with one bolt connecting two or three plates. Initially, the behavior of this model with one bolt is analyzed by comparing it with existing bibliography for 3 different types of applied load: tension, shear and a combination of these two. This model includes all necessary considerations: contacts between the plates and the nut, head and shank of the bolt; contact between the plates, as well as friction between them; and pre‐load on the bolt. The model also responds properly to loads parallel and perpendicular to the contact surface between the plates, including prying action effects. These calibrated models are then introduced as super‐elements in empty spaces left on the full connection, through a relatively simple process using the finite element software ANSYS® [1]. Upon filling these spaces, two complete connection models will be evaluated: one with a single plate and another between two T‐stubs. The results obtained with these models will be compared with experimental tests existing in the literature, consisting basically in load‐deformation and ultimate strength curves. These two connection types have a practical application in the way they will be analyzed, and also as part of more complex connections: bolted girder splices (in the region of web beam), beam‐to‐column connections with splice plates or end plate connections, beam splices with end‐plates, as well as many other connections.
02.02: FE welding residual stress simulation: Influence of boundary conditions and material models
Authors: Gkatzogiannis Stefanos , Knoedel Peter , Ummenhofer Thomas
Published: September 2017

A series of finite element weld simulations was carried out for single‐pass welds. Two multi‐phase ferritic steel grades with yield strength of 355 MPa were investigated. Methods for selecting efficiently the boundary conditions of unrestrained and clamped‐down plates were simulated with satisfying results. Furthermore, the influence of the tangent modulus, the coefficient for thermal expansion and the applied model of hardening behaviour on the final field of calculated welding residual stresses (WRS) was analysed. Values, which provide better agreement with experimental results, along with those that lie on the safe side were highlighted.