bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel approach for elastic buckling loads in longitudinally stiffened webs subjected to patch loading
Authors: Graciano Carlos , Loaiza Nelson 
Published: September 2019

ABSTRACTCurrently, in the EN1993‐1‐5 the ultimate strength of a longitudinally stiffened webs is calculated based on a design procedure which considers the ratio between the yield resistance and the critical buckling load. In the available formulation which is based on numerical modelling, the critical load increases with the relative position of the longitudinal stiffener. This behaviour contrasts with that observed at ultimate limit state, several experimental results have shown that the ultimate strength increases when the longitudinal stiffener is placed closer to the loaded flange. To solve this problem, new hypotheses of boundaries restrictions at the stiffener location are presented to model the elastic buckling behaviour of webs subjected to patch loading. A comprehensive finite element model is presented in this study to evaluate theses hypotheses by varying the web and longitudinal stiffener dimensions. Finally, a methodology to model the buckling behaviour of stiffened webs is presented.
Fatigue design of tension components: Revision and further development of EN 1993‐1‐11
Authors: Annan Rachid , Bechtold Martin , Friedrich Heinz , Maljaars Johan , Misiek Thomas , Paschen Michael 
Published: September 2019

ABSTRACTDuring the ongoing revision of EN 1993‐1‐11 “Design of structures with tension components” the current fatigue design rules were subjected to a critical review. This results in modifications and amendments, including the adjustment of several parameters. The present paper gives an introduction as well as background information on those changes.
European buckling curves for aluminium compression members: A review of proposals for revision
Authors: Misiek Thomas , Norlin Bert , Höglund Torsten 
Published: September 2019

ABSTRACTAs part of the ongoing revision of the Eurocodes, the regulations in EN 1999‐1‐1 on the buckling of aluminium compression members were also subjected to a critical review. This resulted in the need to revise the regulations for non‐welded compression members and for longitudinally welded compression members.The introduction of a buckling class C for soft tempers and minor adjustments in the allocation of the individual alloys and tempers to buckling classes A and B can be understood as a fundamental change. The new allocation is presented and explained.The required buckling curve for non‐welded columns made of materials of buckling class C was introduced in prEN 1999‐1‐1. In this context, minor improvements have also been made to buckling curves A and B. The curves are presented and compared with the results of numerical investigations. The comparison is done graphically as well as statistically (based on EN 1990, Annex D). For the design provisions of longitudinally welded aluminium compression members, a more extensive revision was necessary. The design concept was revised and switched to the use of separate buckling curves which are presented here. These curves are also compared with the results of numerical investigations.
Medium to high cycle fatigue investigation on hot dip galvanized structural steel welded joints
Authors: Viespoli Luigi Mario , Mutignani Francesco , Berto Filippo 
Published: September 2019

ABSTRACTHot dip galvanization offers stable and lasting corrosion protection to steel structure, both acting as a barrier for external agents and inducing galvanic protection, through the deposition of a thin layer of zinc on the steel structure by submersion in a molten bath of the metal. Current standards for welded steel structures subjected to fatigue loads do not allow the use of the technique, while the cost for maintenance, repair or failure due to corrosion has an elevated worldwide impact. A series of hot dip galvanized structural steel welded specimens was tested with the aim of increasing the understanding of the damage and failure of a structure that has undergone such treatment. The goal is to define whether the use of hot dip galvanization poses a threat to structural safety and if this is eventually accountable for with the use of a certain corrective coefficient for the fatigue classes reported in the regulations. A revision of old fatigue data is here reported to critically discuss the new results presented.
Innovative composite deck slab for railway bridges: Experimental investigations on the fatigue resistance of the dowel strips
Authors: Takács Patrik , Fink Josef , Pardatscher Herbert , Petraschek Thomas 
Published: September 2019

ABSTRACTAt TU Wien, Institute of Structural Engineering, Research Centre of Steel Structures, a new, extremely slender steel‐concrete‐steel composite (SCSC) plate is under investigation to meet the requirements of today's standards related to the geometric conditions and noise emission in the substitution of old railway bridges. The multi‐layer structure of the plate consists of two steel cover plates with an unreinforced concrete core, hence the name sandwich plate. Perforated shear connectors, welded alternately to only one of the outer steel plates, work together to ensure the transmission of the shear flow between the outer plates, by the activation of diagonal concrete compression struts between neighboring dowel bars. After the examination of the static load‐bearing capacity in former research programs (1), the current investigations are focussed on the fatigue behaviour of the SCSC plate, whereby the main focus lies on the investigation of the relation between the amplitude of the traffic load and the bearable number of load cycles of the SCSC plate till crack initiation in the shear connectors.A detailed description of the numerical modelling of the SCSC plate using the Abaqus/Explicit (2) software and the calculation of the fatigue life of the dowel strips using the notch strain concept are described in (3; 4; 5). This paper gives an overview of the planning, execution and evaluation of the experimental investigations and compares the experimental and the numerical results regarding the fatigue life of the dowel strip.
Experimental study of epoxy coatings for fire protection of bridge cables
Authors: Tolstrup Jonas , Giuliani Luisa , Narasimhan Harikrishna , Jensen Jakob Laigaard , Jomaas Grunde 
Published: September 2019

ABSTRACTAn experimental study on the performance of epoxy coatings exposed to different fire conditions was undertaken in order to assess if such paints could be a viable passive fire protection solution for bridge cables. Epoxy paints are of interest for this application due to their high resistance to environmental agents and the capability of resisting hydrocarbon fires. However, recent studies have shown that the performance of water‐ and solvent‐based intumescent coating are strongly affected by the fire condition, and particularly the heating rate, and it is essential to assess if these challenges are also present for epoxy paints. Therefore, two different epoxy coatings were applied to small steel plates and exposed to different constant heat fluxes ranging between 20 and 80 kW/m2 in a cone heater. The results of the experiments are presented in terms of expansion of the coating, temperatures of the substrates and efficiency of the coating, calculated as relative difference between the temperature of an uninsulated sample and a sample coated with the coating. The outcomes of the experiments indicate that there is a dependency between the incident heat flux and the char development and thus the ability to protect the substrate.
Development of fire protection for bridge cable systems
Authors: Jensen Jakob Laigaard , Narasimhan Harikrishna , Giuliani Luisa , Jomaas Grunde 
Published: September 2019

ABSTRACTFire protection of bridge cable systems has been identified as an important mitigating action with respect to operational risk as well as the safety of existing and new bridges. In particular, cable supported bridges have been demonstrated to be vulnerable to vehicle fires.With the design of fire protection concepts for New Little Belt Bridge and Great Belt East Bridge, a process with development of fire protection of cable systems has been started. The project is based on the development of a fire protection concept for main cables based on insulation mats and currently a concept is being developed with use of intumescent coatings.The R&D project and handling of the design challenges on cable systems on suspension bridges is presented, and it includes details about the main cable, cable clamps and suspenders based on numerical modelling and testing of the steel performance during fires up to 1100°C.The fire protection relies on use of insulation mats and intumescent coatings and in developing the concept, one of the main challenges is to document the performance of the design concepts unique to each bridge. Furthermore, it is difficult to get access to information on material performance in such particular applications. Hence, in the current project, it has not been possible solely to rely on the supplier information and it has been necessary to carry out numerical modelling of performance during fire as well as use of laboratory testing.In summary, the objective is to investigate the combined performance of the steel cable and the applied insulation concept. For solutions, design has not only to consider the fire protection of steel but also to address issues regarding cable durability and allowance for operation and maintenance.
Flexural behaviour of engineered cementitious composite encased high strength steel composite beam
Authors: Kabir Md. Imran , Lee C. K. , Rana Mohammad M. , Zhang Y. X. 
Published: September 2019

ABSTRACTIn this paper, the flexural performance of a new type of composite beam comprised of High Strength Steel (HSS) section encased by polyvinyl alcohol‐engineered cementitious composite (PVA‐ECC) and lightweight concrete (LWC) is studied. An experimental investigation on the flexural performance of HSS beams encased by different thickness of ECC is conducted and their performances are compared with bare HSS beam and normal strength concrete (NSC) encased HSS beam. Four‐point bending tests are carried out on simply supported beams including one bare HSS beam, one NSC encased HSS (NSC‐HSS) beam and two ECC‐LWC encased HSS (ECC‐HSS) beams. For ECC‐HSS beams, both top and bottom flanges of the HSS sections are encased with PVA‐ECC while the web was encased by LWC. The test results showed a significant improvement in load‐carrying capacity, ductility and failure modes for ECC‐HSS beams when comparing with bare HSS and NSC‐HSS beam.
Stronger steels, higher penalties: Evaluation of flexural buckling experiments performed on welded high‐strength steel struts
Authors: Sabau Gabriel , Lagerqvist Ove , Baddoo Nancy 
Published: September 2019

ABSTRACTStability in a structural mechanics context has posed a continuous problem throughout history for mathematicians, engineers and architects. Flexural buckling is one of the main problems steel structures are faced with in order to ensure an economic design. Different equations have been derived to estimate critical loads that could lead to collapse of compressed members. The buckling resistance of compressed struts are calculated in Europe using the European buckling curves. The method of calculating the resistance implies the use of a reduction factor based on 5 different buckling curves. These buckling curves differ based on type of cross‐section, fabrication method and steel grade. The method has been generally accepted since it proved to be reliable and versatile. The current design codes are assigning the same relevant buckling curve to the sections made of steels with yield stress of above 460 MPa. This conservative approach is one of the reasons that discourages the use of high‐strength steels in common structural applications, since the designer does not see a direct benefit from the additional steel strength. The first part of the paper briefly describes the origin of the European buckling curves. The second part presents two analytical models for calculating flexural buckling limit loads. Flexural buckling experiments performed on welded box and I‐sections made of high‐strength steel, with the yield stress in the range of 690‐960MPa. The third part analyses the existing buckling experiments and statistically evaluates the models proposed for estimating the resistance of high‐strength steel struts subjected to pure compression. The final part addresses the potential future research in the context of developing adequate flexural buckling curves for high strength steel (HSS) members.
Duplex steel segment gate Södertälje (Sweden)
Authors: Langedijk Walter , de Graaf Jan 
Published: September 2019

ABSTRACTThe construction of a new lock in the Södertälje Canal (currently the largest lock in Scandinavia) is fundamental to be able to meet the continuous growth of marine traffic (both in volume and ship dimensions). The renewal project will ultimately result in an extension of the lock chamber (170 metres in length and 25.3 metres in width), the construction of two new sluice heads including stainless steel lock gates and a new bascule bridge.As required by the client, a special type of lock gate is adopted in the design: a segment gate made of duplex steel (a specific type of stainless steel). Another unique feature of this project is that the bearings and hydraulic cylinders are integrated on a steel skid structure. This complete structure can easily be adjusted in the future to align the main axles in the desired position and direction. This is an important mitigation measure in the design to guarantee the fatigue strength of the steel structures in the event of settlements of the sluice head abutments in long term.This paper aims to give insight into the design challenges and elaborates on the chosen solutions of these innovative duplex segment gates.
Guyed Wind Turbine Towers: Developments and outlook
Authors: Jespersen Martin , Støttrup‐Andersen Ulrik 
Published: September 2019

ABSTRACTIn the quest of reducing carbon emissions, sources of renewable energy, such as wind, are in high demand. Developers of onshore wind farms are increasingly faced with site conditions which are not ideal in terms of harvesting wind energy, such as forest, mountain areas or wind availability.This has several root causes such as: site scarcity, political instruments to ensure energy mix and lack of transmission. Some of the potential challenges for such sites are 1) larger hub height is required to maintain energy yield and reduce the turbulence intensity, 2) installation is costly, 3) road transport is costly from increased diameters of conventional towers, and 4) increased foundation cost for tall towers.Guyed masts have been applied within the field of telecommunications for many years. Previous comparisons of the advantages of guyed masts over self‐supporting towers highlights that positive properties of the guyed mast include: lower cost with height, less erection time and cost‐effective foundations.In order to reduce the cost of tall wind turbine towers a guyed wind turbine (GWT) tower concept, where the conventional steel tubular tower is supported by guy ropes (cable stays) just below the tip of the blade, has been proposed by Ramboll dating back to 2003. It is only in recent years that the hub heights relevant for application of this concept is coming into market. In 2013 Ramboll participated in a research project disclosing the use of guyed towers for constructing tall wind turbine towers, which demonstrated a significant positive cost impact and documented the technical feasibility of the concept.For the concept cost reductions are obtained through the entire supply‐chain of the wind turbine tower: steel consumption, foundations, transport and installation.The paper will give a general introduction to the guyed wind turbine tower concept and update with developments.
Automatically Welded Tubular X‐Joints for Jacket Substructures: Prediction of the Technical Fatigue Crack Location
Authors: Schaumann Peter , Schürmann Karsten , Pittner Andreas , Rethmeier Michael 
Published: September 2019

ABSTRACTTo increase the competitiveness of jacket substructures compared to monopiles a changeover from an individual towards a serial jacket production based on automated manufactured tubular joints combined with standardized pipes has to be achieved. Therefore, this paper addresses fatigue tests of automatically welded tubular X‐joints focusing on the location of the technical fatigue crack. The detected location of the technical crack is compared to numerical investigations predicting the most fatigue prone notch considering the structural stress approach as well as the notch stress approach. Besides, the welding process of the automated manufactured tubular X‐joints is presented.
Local Buckling Coefficient Calculation Method of Thin Plates with Round Holes
Authors: Kelpša Šarūnas , Peltonen Simo 
Published: September 2019

ABSTRACTWhen slender parts of plated structural members are under compression the local buckling may govern resistance of the whole structure. In addition to that, holes in those slender parts may reduce the resistance even more. Knowing that holes in different positions of steel structural members are very common, a simple but as precise as possible calculation method of critical buckling force would be beneficial for engineers. In order to create such a method, which would take the influence of the holes into account, an extensive analysis campaign of elastic buckling of thin plates with holes has been carried out. The finite element method was used for the calculations, and analysis of the obtained results derived to a simple calculation expression.The influence of different positioning and diameters of holes on elastic local buckling force is analyzed in the paper, and the developed calculation equation is presented. The proposed calculation method/ equation can be used by engineers in order to easily predict the elastic buckling coefficients and the critical forces of plates with round holes under compression. In order to add more value for engineers, the factors which have influence on the critical buckling force are commented. Also, recommendations for further development and possible extensions of the method are given in the paper.
Influence of Structural Detailing on the Stability Behaviour of Truss Girders
Authors: Mämpel Silvio , Kraus Matthias 
Published: September 2019

ABSTRACTIn the design of truss structures, stability verifications are often decisive. Especially flexural buckling is of relevant issue. Structural systems are therefore usually stabilised by means of constructional members and components. Depending on the stiffening system and loading, the torsional behaviour and lateral torsional buckling of members can be of importance as well. However, all conventional structures for stabilisation have in common that they in general provide a shear stiffness (by bracings or sheeting) as well as an elastic rotational support.The influence of different structural truss details are analysed with regard to the girder stability. In this context, the stiffness of bracing systems and its position as well as the influence of rotational stiffness provided by purlins are investigated. In doing so, individual truss girders are analysed as well as systems of several girders based on full three‐dimensional beam models. The investigations provide information on the global stability behaviour with respect to different girder quantities stabilized by one bracing system. Additionally, a subset of structural systems are modelled in more detail using shell elements in regions of connections/joints to account for structural detailing influences. Overall, the aim is to identify and focus different effects of structural details on the stability behaviour of lattice girders to promote an economic and safe design.
Out‐of‐Plane Buckling Assessment of Frames through Overall Stability Design Method
Authors: Papp Ferenc , Szalai József , Majid Movahedi R. 
Published: September 2019

ABSTRACTThis article extends the innovative Overall Stability Design Method (OSDM) for steel portal frames with double symmetric I and H cross‐sections. The OSDM utilizes linear buckling analysis and equivalent initial geometrical imperfection in the shape of buckling mode for the assessment of out‐of‐plane buckling resistance. The method was developed for single structural members with two alternative procedures. One of them is the overall imperfection method which uses equivalent amplitude and the other is the overall strength reduction method which follows the classic reduction factor based procedure. Both methods have been validated for fundamental cases of lateral‐torsional buckling and coupled flexural and lateral‐torsional buckling of individual members published recently. In this article these methods are extended for portal frames. The method may be adapted by any commercial design software which is able to execute a relevant transmission of the displacements (namely the warping) through the applied frame corner joints. The overall validation of the method for portal frames needs considerable investigations. This article aims to do the first step by the presentation of the procedure through benchmark examples.
Experimental and numerical analysis of the local and interactive buckling behaviour of hollow sections
Authors: Toffolon Andreas , Müller Andreas , Niko Igor , Taras Andreas 
Published: September 2019

ABSTRACTInadequate knowledge regarding specific local and interactive behavior of slender high‐strength steel (HSS) hollow sections presents an obstacle in implementing these sections in the construction practice. The current approach in the standard is simplified and offers overly conservative results. Dealing with non‐standard cross‐sections only expands on these difficulties. This paper contributes to the on‐going RFCS project “HOLLOSSTAB”, which has been dealing with the aforementioned issues. The project design proposal is based on the “Overall interaction concept” (OIC), and a new set of design rules for hollow sections is currently being developed. In this concept, linear buckling analysis (LBA) is used to obtain the slenderness of the member, and Geometrically and Materially Non‐linear Imperfection Analysis (GMNIA) is used to determine an “overall” buckling reduction factor. Extensive experimental tests are used to validate the method, by correlating the experimental results with numerical test results (GMNIA‐real) and statistically analyzing them. The focus of the tests in this paper is the use of high‐strength steel, ranging from S500 to S890, used for rectangular hollow‐sections and hexagonal‐hollow sections. The state‐of‐the‐art measuring tools available, offer the possibility of precise reverse‐engineering process, creating numerical models based on experimental test, which allows an accurate prediction of the ultimate load capacity of the specimens. Digital image correlation (DIC) allows a review of the buckling shape, comparing numerical model with real shape of tested specimen. The paper aims to validate the numerical models, as well as validity of assumptions on imperfection amplitude.