bluuebunny/crossref_metadata_2025_split huggingface dataset:
13.05: Imperfection force of members under longitudinal action having a variable sign
Authors: Biegus Antoni , Czepiżak Dariusz 
Published: September 2017

ABSTRACTIn the calculation model of equivalent stabilizing force qd (shorter – imperfection force) for both bracing system and purlins consistent with EN 1993‐1‐1 it has been conservatively assumed that the member to be restrained is uniformly compressed within its length by an axial force. This is incorrect when the actual distribution of the axial force is considered as non – uniform, having a parabolic shape and sign – variable characteristic (compression and tension). Thus a different imperfection force is generated in comparison with this given in EN 1993‐1‐1.The actual imperfection loads of the upper flange of the restrained roof rafter being fully fixed to columns have been analyzed. The axial force in the restrained member changes parabolically along its length from tension at the support zone to compression at the central part. Values of tension axial forces Nsup and compression axial forces Nspan depend, among others, on the rigidity of the roof rafter, rigidity of columns and stiffness classification of the rafter to column connection. Parametrical analyzes of the imperfection forces together with evaluation of strains of purlins and bracing system versus axial forces Nsup, Nspan acting in the restrained member have been done. The result of presented analyzes is determination of the safe imperfection force and he strain of purlins and bracing system in different, real design situations and a comparison of obtained results with these based on the conservative model given by EN 1993‐1‐1.
13.15: Seismic design of steel moment resisting frames: Modal strength reduction factors including strength deterioration and panel zone effects
Authors: Loulelis Dimitris G. , Papagiannopoulos George A. , Beskos Dimitri E. 
Published: September 2017

ABSTRACTTraditional seismic design of framed structures uses a single constant value for the strength reduction factor. In this work, explicit expressions for different values of strength reduction factors for the first significant modes of steel moment resisting frames including strength deterioration and panel zone effects are developed. These factors are functions of modal periods and damage and are designed for four performance levels in a performance – based seismic design framework. The above factors are obtained through extensive parametric studies involving 20 steel frames and 100 far – field ground motions and following a two steps procedure: First an equivalent linear structure with the same mass and elastic stiffness of the original non – linear one is constructed based on equivalent modal damping ratios, which substitute the non‐linearities; then use of these equivalent modal damping ratios in conjunction with modal damping reduction factors leads to modal strength reduction factors. Using these factors, one can obtain the seismic design base shear of a frame through response spectrum analysis. Thus, a more accurate and rational seismic design method is established. Numerical examples are presented to illustrate the method and demonstrate its advantages against conventional seismic design methods.
00.04: Structural fire design – Developments in research and assessment of fire in steel and composite structures
Authors: Knobloch Markus 
Published: September 2017

ABSTRACTThis paper addresses structural fire safety, which is a key consideration in the design of buildings, and a topic attracting worldwide attention. Significant advances in research have increased our knowledge on the behaviour of steel and steel‐concrete composite structures in fire. Some areas are becoming well understood (like the behaviour of isolated elements in conventional building materials), while others areas (such as global behaviour of structures in fire, or constitutive modelling of innovative building materials at elevated temperatures) need further investigation. It is the aim of this paper to review progress in this area and to present latest developments with respect to future European structural fire design.
13.17: A comprehensive assessment of eurocode 3 pt. 1.1 & NBR 8800 steel design codes
Authors: da S. Vellasco Pedro C. G. , de Lima Luciano R. O. , da Silva Luís Simões , Simões Rui , Gervásio Helena 
Published: September 2017

ABSTRACTThis paper compares the axial force and bending moment design procedures of Eurocode 3 part 1.1 and the Brazilian Standard NBR8800. This comparison was performed through a series of practical design examples that were executed according to EC3 pt. 1.1 [1] and NBR 8800 [2]. This strategy led to an assessment of some critical design issues present in these two structural steel codes, focusing on the identification of their main similarities and differences. The main conclusions of the above‐mentioned comparisons will be presented in terms of steel profile axial force and bending moment design capacities. The main reason for this result presentation strategy was due to the fact that the most common steel profile tables are constructed in a discontinuous form, where the same steel profile is able to withstand a non‐negligible range of structural design capacities.
15.07: Second‐order direct analysis of long‐span roof structures
Authors: Liu Yao‐Peng , Chan Siu‐Lai , Du Zuo‐Lei , He Jian‐Wei 
Published: September 2017

ABSTRACTLong span roofs are widely used in stadium, shopping mall, public hall, warehouse, airport and so on as they can provide large internal spaces. It is a challenging task to design a long span roof for the structural engineers using traditional linear design method due to uncertainty in the assumption of effective length. Second‐order direct analysis (SODA) shows many advantages over the traditional linear design approach in terms of structural safety and cost efficiency. In this paper, the design considerations and procedures of using SODA for design of long span roofs are presented. Both the P‐Δ and P‐δ effects as well as initial imperfections have been taken into account. More importantly, this innovative method is used to trace the structural behaviour of long span structures during offload process so that the structures can be safely and progressively deformed to their designed position with minimize lock‐in stress. A nonlinear spring element is proposed to capture the behaviour of the mechanical jack which is the device for implementation of offload process. Thus, a comprehensive solution is introduced here for offload analysis of long span structures. Finally, a practical long‐span single layer roof structure in Macau is used to demonstrate the validity and accuracy of the proposed method.
00.05: Validation and verification in design of structural steel connections
Authors: Wald František , Gödrich Lukáš , Kurejková Marta , Šabatka Luboš , Kabeláč Jaromír , Kojala Drahoš 
Published: September 2017

ABSTRACTThe only way to prove correctness of simulated results by Finite Element Analyse (FEA) is through a methodical System response quantity process. Without this approval are the results of FEA meaningless and cannot be used in design process for making any decisions. The System response quantity consist of validation, which compares the numerical solution with the experimental data, of verification, which compares computational solutions with highly accurate analytical or numerical solution, and of benchmark cases, the examples for check of the software and its user on approved and simplified input and output.In the eighties FEA of structural connection was treated by some researchers as a non‐scientific matter. Two decades later it was already a necessarily extension of experimental and analytical work. Today computational analysis, in particular computational mechanics and fluid dynamics, is commonly used as a catalyst of many research fields and an indispensable design tool. The recommendation for design by advanced modelling in structural steel is ready to be used in Chapter 5 and Annex C of EN 1993‐1‐5:2005 [1]. Development of modern general‐purpose software and decreasing cost of computational resources facilitate this trend. The FEA of structural connection is the coming step in structural steel design. As the computational tools become more readily available and easier to use even by relatively inexperienced engineers the proper procedure should be employed when judging the results of computational analysis.This paper describes the System response quantity for Component Based Finite Element Model (CBFEM) which is a multilevel FEA method to analyse and design connections of steel structures, see [2]. The steel plates in connection are analysed in CBFEM procedure by FEA. The proper behaviour of components is treated by introducing a components representing well its behaviour in term of initial stiffness, ultimate resistance and deformation capacity, of bolts, welds etc. To help with this process is prepared a contribution, which summarises the history of achievements of FEA application in structural connections. Contribution shows the currents trends in advanced modelling of connection components and differences of the research oriented design oriented models. The particular attention is dedicated to design models of generally loaded endplates.
15.08: Influence of deterioration modelling on local deformation demands in steel moment frames
Authors: Bravo‐Haro M. , Tsitos A. , Elghazouli A.Y. 
Published: September 2017

ABSTRACTThis paper assesses the influence of the cyclic strength and stiffness degradation on the local demands in moment resistant steel frames (MRF), designed according to Eurocode 8. For steel structures, local demand is frequently evaluated by means of plastic rotation of structural members. This local response is relevant both for the design of new structures and particularly for the assessment or safety evaluation of existing structures. Recent studies have illustrated the weaknesses of the local demand prediction methods based on linear analysis. When predictions based on linear analysis were contrasted against nonlinear models, mismatches up to 100% were found. However, those nonlinear analysis approaches have not considered the effect of cyclic strength and stiffness degradation. In this study, degradation models are used and calibrated for assessing structural collapse scenarios. A set of twelve MRF systems, designed according to the provisions of Eurocode 3 and Eurocode 8, are examined using two different modelling approaches: a degrading model and a conventional non‐degrading approach. The frames are subjected to different levels of given inelastic demands by means of a scaling procedure using a suite of ground motion records. Plastic rotations are directly measured during the nonlinear analyses and consequently contrasted to quantify the effect of degradation at different levels of induced inelasticity. It is shown that using degrading models results in local inelastic rotations which can be significantly higher, reaching up to 25% more than without degradation. Finally, the implications of the findings on current European seismic design procedures are outlined.
15.16: Vibration Analysis and Human Comfort Investigation of a Steel‐Concrete Composite Building under Nondeterministic Wind Loadings
Authors: da Silva José Guilherme Santos , Barboza Rafael Rangel 
Published: September 2017

ABSTRACTBased on a favourable economic scenario combined with a significative technological advance in science materials and also construction processes, it must be emphasized that the Brazilian cities have shown substantial growth, regarding the construction of tall and slender buildings. This architectural trend has conducted the design of these buildings to solutions composed by very flexible structural systems, resulting in slender buildings with very low natural frequencies values and therefore more susceptible to problems of excessive vibrations, undesirable crack openings and even discomfort to the occupants. This way, having in mind the slenderness levels presented more recently, these buildings need to have their structural dynamic behaviour investigated, in order to ensure the human comfort. Thus, this research work aims to investigate the dynamic structural behaviour and also evaluates the human comfort of tall buildings, when subjected to the non‐deterministic action of the wind. This way, the structural behaviour of a forty eight‐storey steel‐concrete composite building with 172.8m high subjected to the nondeterministic wind dynamic actions is investigated. The results obtained along the numerical analysis, in terms of the displacements and accelerations values, in time and frequency domain, are compared with the limits proposed by technical guides and design recommendations, aiming to evaluate the human comfort levels of the analysed building, regarding to the situations of the design practice.
15.17: Progress in the development of production of heavy plates. S355‐S460ML till 100 mm at NLMK DanSteel
Authors: Goli‐Oglu Yevgen , Greisen Zibrandt 
Published: September 2017

ABSTRACTAt the end of 2012 a new 4200 mm rolling mill was put into service in Frederiksvaerk at NLMK DanSteel. Since then the company has focused on production of heavy plates for construction, offshore, shipbuilding and boiler purposes, i.e. steel plates with higher mechanical properties. The company is constantly expanding its product program assortment with regards to sizes and grades. As an example of this, the company in 2015 expanded the range of thermomechanical rolled heavy plates, of structural steel of strength category S355ML, S420ML, S460ML up to 100 mm and received the achieved approval for CE‐marking of these grades.The article presents slab quality requirements, some features of production technology for specified quality and thickness categories as well as enhanced mechanical test results, including evaluation of the anisotropy of the hardness gradient and toughness downp to −80°C both in longitudinal and transverse directions, showing the actual level of low temperature impact toughness properties in ¼ and ½ of heavy plate thickness.Some additional investigations of weldability of low carbon heavy plates were done. The micro hardness of the basic sections in the weld joint of micro alloyed low‐carbon steel heavy plates is investigated. Two‐coordinate measurements of the micro hardness in the basic HAZ are described. The influence of post weld heat treatment on the micro hardness of opposite walls of the weld joint is determined.
16.01: Bjørnafjorden suspension bridge TLP concept
Authors: Sørensen Jesper 
Published: September 2017

ABSTRACTThe Bjørnafjorden TLP (Tension Leg Platform), a multi span suspension bridge solution, is one of the possible fjord crossings options considered as part of the ambitious “Ferry‐free Coastal Highway E39” under development in Norway. The original design concept for Bjørnefjorden was very much similar to that of a conventional suspension bridge using central locks between main cable and bridge deck to distribute movements equally to the bridge ends. However since the bridge is of the multi‐span type, the inherent flexibility of the pylons caused a severe of in‐plane stability of the original system leading to large vertical displacement of the deck. To mitigate this effect top cables have been introduced between pylon tops preventing these from excessive longitudinal displacements and thereby also limiting the vertical deck displacement from traffic load. In this paper the different concept challenges for the Bjørnafjorden TLP solution is outlined.The suspension bridge has a total of four pylons – a northern and southern pylon of concrete located near shore, while two central steel pylons are supported by TLP's at 550m and 450m depth. The TLP's, as well known from off‐shore industry, consist of pre‐tensioned steel pipes anchored in the seabed and at the surface connected to a large steel “floaters” onto which the towers are placed. The main spans are 1300–1400m and the bridge has an overall length from anchorage to anchorage of about 5200m.Due to the long tethers of the TLP the central pylons are relatively unrestrained to move up to 20m horizontally and thus in order to achieve sufficient stability of the bridge system a special feature in form of top cables are introduced. The top cables connect the tower top of all four pylons and are anchored to the bridge anchor blocks together with the main cable.The bridge structural system is the outcome of innovative thinking and a fine example on how a few unconventional features can make a very conventional bridge system work in challenging conditions. As the bridge is floating it is essential that the structure is light and therefore the primary structures are in steel.
16.04: High strength steel (HSS) S690 in highway bridges: Comparative design
Authors: Pedro José J. Oliveira , Reis António J. , Baptista Cláudio 
Published: September 2017

ABSTRACTThe use of High Strength Steel (HSS) S690 in highway bridges decks is not yet widespread. A research program investigated the optimal use of HSS S690 within bridges was conducted.A comparative design is presented for a 21.5 m wide highway bridge, with a typical 80 m long span and a composite steel‐concrete twin plate girder deck. Two designs are compared, using the Eurocodes: Design (A) adopted standard S355 NL steel grade whereas Design (B) uses HSS S690 QL or QL1 on the main girders.Comparison between the two designs shows that using S690 enables reductions of 25% on the steel weight and about 65% on full penetration welding volume, compared to design with S355. The deck can be slender using HSS and have thinner plates, but it is more susceptible to local buckling phenomena. Brittle fracture is slightly less dimensioning using HSS, but girders are likely to be much more prone to fatigue, which proves to be the main issue of the design together with the local buckling phenomena.The critical fatigue welded joints are analysed according to EN 1993–1‐9. For plate girders with transverse stiffeners, fatigue presents a major design constraint, namely on span sections, due to allowable plate stresses range near the welded joints.Standard fatigue load model FLM3 with the damage equivalent factor concept is used for fatigue design of several plate girder details. Fatigue resistance of the welded joint between the transverse stiffeners and the bottom tension flange proved to be the most relevant aspect of the design of the composite steel‐concrete twin plate girder deck designed for HSS S690.
16.06: Realization and launching of the Adda‐Bitto Viaduct in Italy
Authors: Maiorana Emanuele , Sartori Lorenzo , Lazzari Massimiliano , Pellizzer Luca 
Published: September 2017

ABSTRACTIn Valtellina near Sondrio, a large viaduct is to be built which will permit overpassing the town of Morbegno more quickly. Given the impossibility of carrying out installation operations using cranes from the ground and to limit the environmental interferences due to the presence of two rivers, the erection method was by launching, starting from an abutment towards the opposite one. The launching activities covered only the steel part of the deck, 167 m long, overpassing the Bitto stream and the River Adda, while the remaining portions of the deck, located near the abutments, were assembled, after completion of the launch, by crane from the ground.
16.08: The dynamic behaviour of the third Bosporus Bridge
Authors: de Ville de Goyet Vincent , Duchêne Yves , Propson Arnaud 
Published: September 2017

ABSTRACTWith a length of 2240 m, this new hybrid cable cable‐stayed bridge have a main span of 1408 m. Like the Brooklyn bridge (New York), the main span is supported on one side by main cables with hangers and on the other part by stay cables. The concrete pylons reach the height of 320 m, while the deck 58 m wide and 5.50 m high bears twice four bands for international road traffic, two lanes of railway and two lateral sidewalks for pedestrians. The third bridge over the Bosporus, called Yavuz Sultan Selim Bridge is located at the North of Istanbul near the black Sea. Exceptionally bridge leads to exceptional loadings. In an area of high seismicity and in view of its length, the bridge must be checked under differential accelerations time histories in each support. Such a bridge is automatically extensively studied under the wind effects on basic data analysis of weather stations and numerous wind tunnel tests to verify its behaviour under dynamic wind gusts and verify the aerodynamic instabilities that could occur both in service and during the construction phases. For road and railway traffic, the response of the bridge depends on the speed of the train; to limit the longitudinal displacements, pendular bearings have been added. The bearings are also very useful under seism.
16.09: Influence of arch bridge skewness
Authors: De Backer Hans , Outtier Amelie , Van Puymbroeck Evy , Van Bogaert Philippe 
Published: September 2017

ABSTRACTThis article performs a parameter study on a detailed finite element model of a simple arch bridge consisting of a single arch. The objective is to investigate the influence of different hanger arrangements, dimensions and finally a variation of the angle of skewness between the arch axis and longitudinal bridge deck axis. The influence on the stresses, forces and bending moments in the bridge deck girders, hangers and arch is examined. Finally, a buckling analysis is performed on all different models and the change in critical buckling load is discussed.The displacements in the bridge deck stay the same for small angles of skewness. Starting from an angle of ± 13°, the position of maximum deflection in the bridge deck shifts towards the ends of the bridge deck instead of being situated staying in the middle. This can be explained by the influence of the wind load acting on the arch structure and the direction of the horizontal resultants of the hanger forces. This can cause partial relaxation, thus ensuring a small uplift at the longitudinal girders of the bridge deck. This is also the cause for the higher displacements in the arch. The torsion effect in the arch results in a counter clockwise rotation of the arch. When performing a buckling analysis on the changing angle of skewness, it is found that this initially has only a small impact on the critical load factor.