bluuebunny/crossref_metadata_2025_split huggingface dataset:
21.08: Evaluation of steel buildings by means of non‐destructive testing methods
Authors: Fox Christian , Doktor Dipl.‐Math. Markus , Kurz Wolfgang , Seiler Georg , Wu Haoran , Boller Christian 
Published: September 2017

ABSTRACTNon‐destructive testing (NDT) methods have become increasingly attractive for verification of existing steel infrastructure including buildings. However destructive testing is still state of the art combined with load condition monitoring and yield limit determination of the steel elements incorporated in buildings.In many of the existing buildings, the characteristics of the steels used are often not known anymore. A statement of the residual load‐bearing capacity such as of incorporated steel beams within a building can be made if there is a means to determine it reliably. This opportunity principally exists via micromagnetic as well as ultrasonic measurements to be shown here. Magnetism even allows the yield strength of ferromagnetic steel beams to be determined. An ultimate limit state design can be proven by real material characteristics where model uncertainties have been excluded and not by selected minimum values only.If the residual load‐bearing capacity of steel beams cannot be guaranteed today, higher static loads can only be transferred by strengthening measures, such as welding or bolting additional parts. However, if the true loading as well as material condition could be determined those measures might be avoidable. A means on how to do this is by ultrasonic measurement since the propagation speed of ultrasonic waves in a steel is influenced by its strain and stress conditions. Acousto‐elastic characteristics show the correlation between the propagation of speed and the current state of stress. Those characteristics have therefore been determined on beams in lab tests and compared to strain gauge measurements, where the acoustic wave speeds have been determined first as a speed without the influence of load, before loaded conditions were considered.Material texture due to rolling processes plays a significant role in steel structures too. It has a ten times higher influence on the ultrasonic measurements than stresses due to loading have. Hence a clear separation between texture and stress related influences is therefore essential. Particularly since all those measurement results may further be exposed to significant scatter, statements regarding confidence bands of the determined stresses have to be made. This therefore includes statistical tests that will provide the respective reliability required for the concept to be competitive. The respective NDT techniques combined with suitable stochastic methods are shown below.
P05.01: Simulation of the spatial behaviour of tubular façade scaffolding
Authors: Dolejš Jakub , Ilčík Jiří 
Published: September 2017

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

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

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

ABSTRACTThe design of full strength bolted beam‐to‐column beams considering the overstrength factor for the beam material according to EN 1998‐1 is particularly demanding, especially in case of heavy beam profiles in combination with higher grade material (e.g. S355). The elastic design of the full strength connection leads to very stocky joint. The component method presented in EN 1993‐1‐8 that was developed mainly for the design of partial‐strength joints may also be used for the design of these connections, but its application is limited mainly to experts.This paper studies bolted beam‐to‐column joints under monotonic and cyclic loading, particularly hot rolled HEA 600, S355 beam with high bending strength. Two different configurations of bolted connection of HEA 600 to column are studied in order to achieve full strength connection as defined in EN 1998‐1, namely eight‐bolt rib stiffened and haunched stiffened joint configuration. Both joint configurations are first calculated according to EN 1993‐1‐8 using component method, where bolt forces and joint bending strength were determined. The first joint is also designed according to the procedure given in ANSI/AISC 385‐10. The numerical model, based on this design, was built in FE software Abaqus in order to observe the behaviour under monotonic and cyclic loading. The cyclic loading was defined according to the ECCS and ANSI/AISC 341‐10 procedures. The bolt preload was also studied.
01.12: Development and validation of design criteria for free from damage steel joints
Authors: D'Aniello Mario , Zimbru Mariana , Latour Massimo , Francavilla Antonella , Landolfo Raffaele , Piluso Vincenzo , Rizzano Gianvittorio 
Published: September 2017

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

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

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

ABSTRACTThe analysis and modelling of the ultimate behaviour of the beam‐to‐column connections is certainly one of the most studied topics in the field of steel structures. In particular, seismic design of steel frames is commonly carried out to assure the dissipation of the seismic input energy in the so‐called “dissipative zones” which have to be properly detailed in order to assure wide and stable hysteresis loops. Once avoided the yielding of columns, beam‐to‐column joints play a role of paramount importance. In fact, beam‐to‐column joints can be designed either as Full Strength (FS) or Partial Strength (PS). In the first case, the seismic input energy is dissipated by means of plastic cyclic excursions of the beam ends. In the second case, dissipation requires the plastic engagement of ductile joint components.This paper addresses the design criteria to be adopted to assure a full‐strength full‐ductility behaviour of Unstiffened Extended End‐Plate (U‐EEP) beam‐to‐column joints. The validation of the design procedure is accomplished by three‐dimensional finite element analyses with ABAQUS 6.13 software.
01.24: Moment‐resisting beam‐to‐column connections of corrugated web I sections
Authors: Aydın Recep , Yüksel Ercan , Yardımcı Nesrin 
Published: September 2017

ABSTRACTThin sinusoidal corrugated web I‐sections have been utilizing commonly in recent years. Though, there are scarce number of studies about their connections.The moment‐resisting extended end plate type beam‐to‐column connections of sinusoidal corrugated web I sections are assessed by means of experimental studies to reveal the important response characteristics. Three full scale beam‐to‐column connections were tested in the Structural and Earthquake Engineering Laboratory of Istanbul Technical University. Although two of the specimens have corrugated‐web panel zone, the third one has relatively thicker flat plate in the panel zone and its near‐vicinity. Double diagonal stiffeners are used in the sinusoidal panel zone of one specimen.It is obtained that two distinct specimens exhibit the comparable responses in terms of the stiffness and strength properties.
01.26: Reliability assessment of flange cleat beam‐to‐column joints
Authors: Skejic Davor , Rizzano Gianvittorio , Curkovic Ivan 
Published: September 2017

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

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

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

ABSTRACTWelding‐induced residual tensile stresses and distortion have become a major concern in relation to the structural integrity of welded structures within the offshore wind industry.The stresses have a negative impact on the integrity of the welded joint, as they promote distortion, reduce fatigue life, and attribute to the corrosion cracking and brittle fracture in the weld components.This study investigates the influence of plate thickness on the welding‐induced residual stresses. The residual stresses are investigated through experiments and in accordance with existing production procedures leading to a better understanding of the distribution and development of the welding residual stresses. This can later be used to optimize the fatigue design, providing a more efficient and improved design. In this context, the current research is expected to benefit the offshore industry by leading to an improved design, which consequently may be included in future norms and standards.Submerged Arc Welding (SAW) was used to make a fully penetrated butt weld in 10 mm and 40 mm thick steel plates with the same welding parameters as used in the production procedures.The base material is thermomechanical hot‐rolled low‐carbon fine‐grained S355ML steel in accordance with the European standard DS/EN 10025‐4 [1].The welding temperature profile during welding was recorded by embedded thermocouples and the hole‐drilling method was used to measure the near‐surface residual stress state.