bluuebunny/crossref_metadata_2025_split huggingface dataset:
10.11: Fire design of rectangular hollow section joints
Authors: Bączkiewicz Jolanta , Malaska Mikko , Pajunen Sami , Heinisuo Markku 
Published: September 2017

ABSTRACTThe component method is a design approach for the characterization of the mechanical properties of structural joints and it is referred to in Eurocode 3 Part 1‐8. Eurocode design rules for open sections are already based on the component method. The design rules for joints between tubular hollow sections are still based on simple theoretical mechanical models validated against experimental test results. However, there are research activities in progress to extend the application of the component method also to hollow section joints in the next revision of Eurocode. The fire design of steel joints is carried out in accordance with Eurocode 3 Part 2. Eurocode gives only a guidance on how the temperature of the joint components can be assessed based on the local values of thermal resistance of the joint's fire protection. The method is not sufficient for the component method and Tampere University of Technology is currently carrying out experimental fire research to better understand the temperature distributions in the vicinity of the joint. The aim of the research is to develop experimental methods to determine steel temperatures at the actual joint component, spring, locations and to transfer this information into the joint design approach based on the component method. This paper introduces an experimental research demonstrating the actual temperature distributions within the joint area and highlights the differences between the failure modes and the design criteria at normal temperature design and fire design of a joint.
10.13: Bending resistance evaluation of shallow floor beams exposed to fire
Authors: Leskela Matti V. 
Published: September 2017

ABSTRACTFor the moment, the Eurocode 4 standards give detailed analysis rules merely for the standard or ordinary composite beams where the concrete section rests on the top flange of a steel beam. In contrast to shallow floor beams (abbreviated as SF‐beams), where only the bottom flange is directly exposed to fire, the ordinary composite beams do not have any inborn fire protection. Although the SF‐beams are not excluded from the scope, no special design rules are given for them, and they only appear in one schematic figure in EN 1994‐1‐2. The basic method for evaluating the bending resistance of fire exposed composite beams is based on the employment of rigid‐plastic stress blocks in steel and concrete. However, it is also possible to utilize elasto‐plastic analysis, where the flexural strain distribution and the corresponding stresses are taken into account, and the maximum compressive strain of the concrete could be set to control the straining. The analysis results between the rigid‐plastic and elasto‐plastic sagging bending resistances of fire exposed SF‐ beams are compared and the additional useful information obtained from the latter analysis is illustrated. For any strain distribution that fulfils the equilibrium of internal stress resultants of the composite section, there is a well‐defined bending moment, curvature and bending stiffness. The data following from the elasto‐plastic stress analysis can further be utilized for evaluating nominal deflections that cannot be associated with the rigid‐plastic resistance analysis.
10.16: Behaviour of high‐strength bolts at elevated temperatures under double‐shear loading
Authors: Seif Mina , Weigand Jonathan , Peixoto Rafaela , Vieira Luiz 
Published: September 2017

ABSTRACTDuring fire events, connections in steel structures may be subjected to large unanticipated deformations and loads. These fire effects can produce failures of connections, including local buckling of the connection zone, rupture of connection plates, shear rupture of bolts, and bolt tear‐out rupture of beam webs. Thus, a key issue in evaluating the response of structural systems to fire effects is the proper representation of material behaviour, including fracture, at elevated temperatures. Temperature‐dependent material behaviour of structural steel plates has been studied by many researchers, both experimentally and numerically. However, the behaviour of structural steel bolts at elevated temperatures, especially under shear loading, is not well established in the literature.This paper presents results from recently conducted tests of high‐strength structural bolts subject to double shear loading at elevated temperatures. The parameters varied between tests included the bolt grade, bolt diameter, and temperature. Bolt grades A325 and A490 were tested. For each bolt grade, three different diameters were tested (19 mm, 22 mm, 25 mm) at five different temperatures (20 °C, 200 °C, 400 °C, 500 °C, and 600 °C). Three tests were conducted for each combination of parameters. Degradation in the mechanical and material properties were characterized. In addition, a new component‐based model for high‐strength bolts was developed based on the experimental data. The component‐based model is shown to accurately account for the temperature‐dependent degradation of bolt shear strength and stiffness, while also providing the capability to model load reversal.
10.17: Mechanical properties of high strength Q690 steel at elevated temperatures
Authors: Wang Weiyong , Zhang Linbo 
Published: September 2017

ABSTRACTHigh strength steels have been used extensively as primary load bearing structural members in many applications in the building industry. Therefore, fire safety design of structures using such steels has become more important. Deterioration of mechanical properties and creep deformation are considered the most important factors affecting the behaviour of steel structures in fires. A research project based on experimental studies was, therefore, undertaken to investigate the deterioration of mechanical properties and creep of high strength Q690 steel with nominal yield strength of 690MPa. Tensile coupon tests were undertaken to determine the mechanical properties of this steel at temperatures ranging from 20 to 900°C. Test results showed that the currently available reduction factors are not applicable to fire safety design of high strength Q690 steels. Therefore, new predictive equations for the mechanical properties of yield strength and elasticity modulus were developed at elevated temperatures. Creep test were also carried out to quantity the creep deformation of Q690 steel at temperatures ranging from 450 to 900°C. Results from creep tests are utilized to develop relations for expressing creep as a function of temperature and stress. These relations, which are based on Fields & Fields model, can be utilized to account for creep effect in modelling the response of Q690 steel structures exposed to fire.
10.19: The steel and fibre‐reinforced concrete circular hollow section composite column exposed to fire
Authors: Illia Tkalenko , Alexey Tretyakov , František Wald , Josef Novak , Radek Stefan , Alena Kohoutková 
Published: September 2017

ABSTRACTThe recent development in technology of production and transport of the steel fibre‐reinforced concrete enables its utilization in composite steel‐concrete structures. This work is focused on development of mechanical behaviour and design model of circular hollow section (CHS) composite steel and fibre‐concrete (SFRC) column at elevated temperature. Research includes two levels accuracy/complexity, allowing simplified or advanced approach to design following the coming changes in European standard for composite member design in fire (EN1994‐1‐2:2005) [1]. Experimental studies of the project include mechanical tests of heated fibre‐concrete samples in tension and compression, thermal behaviour under uniform and non‐uniform loading of stubs of CHS and tests of full scale SFRC CHS columns in steady‐state and transient‐state regimes. Developing advanced finite element method (FEM) simulation of global mechanical behaviour of SFRC CHS columns is a multi‐levelled composite mechanical and thermo‐model and provide numerous numerical experiments. Together with standard steel material model in fire, FEM model of mechanical behaviour of fibre‐reinforce concrete at elevated temperature is prepared. Validated simplified and advanced thermal model of SFRC CHS at elevated temperature gives temperature fields and moisture distribution inside section which depends on direction, heat flux, sizes and gives possibility to model different fire cases of full‐scale columns in bending and buckling at elevated temperature.Prepared analytical and simplified FEM mechanical model of column is taking in account degradation of mechanical properties, analytical models of transfer of heat inside column section and provides simplified solutions for designers.
10.22: Comparing the fire behaviour of composite columns made with concrete filled double‐skin and double‐tube steel sections
Authors: Camargo Aline L. , Rodrigues João Paulo C. , Fakury Ricardo H. , Lopes Ruben 
Published: September 2017

ABSTRACTThe use of composite concrete filled hollow columns has increased in the last decades. This type of column has several advantages, such as the exemption of using formworks, a higher load bearing capacity and the prospect use of smaller cross sections. Although it has a good behaviour in fire situation, the use of slender columns, mainly in tall buildings, makes necessary to find solutions for increasing the fire resistance. In this sense, this paper presents a comparative experimental study on the fire resistance of composite columns made with concrete filled double‐skin and double‐tube steel sections and with restrained thermal elongation. A set of fire resistance tests, on a special set‐up, were carried out. The double‐tube columns had two steel tubes, one external and one internal, with approximately half the diameter of the outer tube, both tubes were concrete filled. The double‐skin columns had also two steel tubes, but the inner tube was void. Several parameters were investigated, such as the load level, stiffness of the surrounding structure and type of concrete infill. The paper presents results for fire resistance, restraining forces, axial deformation and deformed shapes of the tested columns.
10.26: Parametric numerical analysis of cold‐formed steel Σ‐shaped beams under fire
Authors: Laím Luís , Rodrigues João Paulo C. 
Published: September 2017

ABSTRACTA numerical investigation into the structural behaviour of cold formed steel beams commonly used in warehouses and industrial buildings subjected to fire is presented in this paper. The structural performance of cold‐formed steel beams under fire conditions has been studied over the last years. However, the great majority of them have been performed on single and lipped channel beams and assumed that the internal forces and moments at supports of the members remain unchanged throughout the fire exposure. Hence, a detailed parametric numerical investigation into the response of axially and rotationally restrained compound cold‐formed steel beams in fire has been addressed in this paper. Therefore, in the first phase of this research, a suitable finite element model was developed and calibrated with results of experimental fire tests previously carried out by the authors. And then, a parametric analysis was undertaken using the calibrated finite element model with the purpouse of investigating numerically the effect of some parameters such as section geometry, initial applied load on the beam, slenderness and the influence of those two kinds of elastic restraint on the critical temperature of the beams.Finally, the results of this research showed mainly that the critical temperature of this type of beams with elastically restrained thermal elongation may drop significantly and, beyond a certain value of axial or rotational stiffness of the surrounding structure it may be no longer possible to change the fire response of them.
10.29: The thermal response of corrugated web beams subjected to fire
Authors: Both Ioan , Kyzlik Petr , Vacha Jaroslav , Wald Frantisek , Zaharia Raul 
Published: September 2017

ABSTRACTThe corrugated web beams represent an alternative for material saving by decreasing the web thickness. By reducing the web thickness to values of 1.5 mm to 3 mm, the thermal massivity of the web is reduced, leading to faster temperature increase in fire situation. Moreover, since the flange thickness is unchanged compared to a common flat web beam, the temperature gradient between the two parts is higher in case of corrugated web beams.In a previous study of the authors, an ISO fire test was performed on five typologies of individual elements in a furnace, in which the temperature development in the corrugated web beams were monitored. Starting from the simple relations provided in EN 1991‐1‐2, an analytical model was proposed to consider the heat transfer by conduction from the web to the flange. Two of the individual elements tested were also studied numerically, using the general purpose computer code Abaqus. The temperatures obtained numerically follow closely the temperatures recorded during the three considered specimens.The present paper further validates the numerical model against the experimental results obtained for the other three specimens and presents a numerical study on the recently added typology of corrugated web beams with the web thickness of 6 mm.
10.30: Mechanical response of steel structures in fire: Influence of different material and creep models
Authors: Dolinar Urška , Ogrin Anita , Planinc Igor , Hozjan Tomaž 
Published: September 2017

ABSTRACTThe paper deals with the influence of viscous creep of steel on the behaviour of steel structures during fire. Two stress‐strain relationships for structural steel, combined with Harmathy's explicit model of viscous creep at elevated temperatures, are presented in the paper: (i) bilinear stress‐strain relationship and (ii) modified Poh's stress‐strain relationship. The presented models have been implemented in self‐developed software Pozar for numerical analysis of mechanical response of planar steel frames in fire. Further on results are validated against experimental ones published by Rubert and Schaumann, 1985. The numerical results, obtained with stress‐strain relationship according to the Eurocode 3, are added for comparison. It is shown that all tested models give satisfactory results for small load ratios. Poh's stress‐strain relationship in combination with Harmathy's model of viscous creep and newly proposed coefficients give the best results among the tested models with explicitly considered viscous creep. However, none of the considered models give good agreement with the experiment at high values of load ratio. Furthermore, the comparison between the different material and creep models is conducted for three heating regimes, namely linear heating regime and fast and slow natural fire development. A prominent influence of the employed material model on the final midspan displacements is observed.
10.33: Flexural buckling behaviour of high strength steel columns under fire conditions
Authors: Winful Dorothy A. , Afshan Sheida , Cashell Katherine A. , Barnes Adrienne M. , Pargeter Richard J. 
Published: September 2017

ABSTRACTIn this paper, a numerical modelling study using the finite element (FE) analysis package ABAQUS [1] has been carried out to study the flexural behaviour of square and rectangular hollow section columns made from high strength steel (HSS) grades S690QL and S700MC at temperatures up to 800°C. The FE model was validated using existing experimental data and then parametric studies were performed on columns with varying length and cross‐sectional properties. The results have been compared with recommendations given in Eurocode 3 Part 1–2 [2]. The analyses showed that the Eurocode is generally conservative with respect to the buckling coefficients derived and safely predicts the buckling behaviour resistance of columns made from S700MC and suggest a lower buckling curve may be needed for S690QL. It was also shown that the 0.2% proof stress rather than the stress at 2% total strain is a better parameter for deriving buckling curves in fire.
10.34: Creep properties of grade S275JR steel at high temperature
Authors: Torić Neno , Brnić Josip , Boko Ivica , Čanađija Marko , Turkalj Goran , Lanc Domagoj , Brčić Marino , Burgess Ian W. , Harapin Alen , Divić Vladimir , Uzelac Ivana 
Published: September 2017

ABSTRACTThe paper describes an ongoing research project which aims to determine the creep properties of European steel Grade 275JR. The purpose of the research is to develop a reliable temperature‐, stress‐ and time‐dependent creep model for this alloy, since there is very little information available in the scientific community regarding its creep properties. The research within the project is focused on a series of stationary creep tests, which will be used to obtain time‐dependent creep strains in the temperature range 400–600°C. The stress range for which the creep evolution is studied in this project is between 25% and 90% of the value of the stress at 0.2% strain at any particular temperature level. Comparisons between the creep output for the alloy analysed and existing creep data are presented in the paper.
10.35: Influence of joint stiffness on the behaviour of steel bearing frame under fire conditions
Authors: Maslak Mariusz , Pazdanowski Michal , Wozniczka Piotr 
Published: September 2017

ABSTRACTThe reaction of the bearing steel frame to the direct fire exposure associated with the influence of monotonically increasing temperature of the constituent components is considered in this paper. For the comparative purposes, the frames with beam‐to‐column joints differing in rigidity are analysed in detail. Depending on whether there are stiffening ribs present, and the location of these ribs if present, the fire resistance of the considered structural component is determined by its failure mode. This may occur as the local instability in the column web or as the destruction of the column flange or beam flange. The internal arrangement of the joint is also one of the factors determining the redistribution of internal forces generated in the frame components when subjected to fire conditions. To show this, the dependencies specifying the relationships between temperature of the frame components and the bending moments and axial forces induced in these components during fire are presented, discussed and mutually compared. These relationships are arrived at after the detailed analysis of a numerical example, in which fire behaviour of three similar steel frames differing in the beam‐to‐column joint rigidity is considered. In the first analysed case the joint without ribbing is examined, while in the second case a joint with horizontal ribs and in the third case a joint with horizontal and diagonal ribs are analysed. The relationships listed above are accompanied by corresponding relationships specifying the dependencies between the steel temperature and the frame beam deflection. Additionally, the rigidity of the flexible supports, modelling the resistance of the columns to the horizontal displacement of the joints, is differentiated in the analysis. In conclusion, it has been shown that the analysed types of the considered frame exhibit substantial differences in the predicted structural response if the joints applied in them and subjected to fire differ in rigidity. Specification of these differences and their qualitative and quantitative description constitute the main objective of this work.
10.38: Effects of heat‐treatment methods on mechanical performance of high‐tensile strength steel subject to elevated temperatures
Authors: Du Yong , Liew J. Y. Richard , Xiong Ming‐Xiang 
Published: September 2017

ABSTRACTThis study is motivated by increasingly prevalent use of high tensile‐strength steel (HTS) in constructions, where fire is one of the extreme conditions that need to be taken into account in design phase. Previous studies showed lack of awareness regarding the effects of heat‐treatment methods on temperature dependent mechanical properties of the HTS. With this research gap being identified, standard tensile tests for Grade S690 steels made from Quench‐Temper (QT) Process and Thermo‐Mechanically Controlled Process (TMCP) were conducted. Transient‐state were adopted. The mechanical properties were compared and their differences were discussed. In General, the elastic moduli were similar for HTSs from different heat‐treatment methods, but the effective yield strength of TMCP‐S690 deteriorated more than that of QT‐S690 at elevated temperatures.
11.02: In‐plane quasi‐static cyclic tests on lightweight steel drywall non‐structural partition walls
Authors: Pali Tatiana , Bucciero Bianca , Terracciano Maria Teresa , Macillo Vincenzo , Fiorino Luigi , Landolfo Raffaele 
Published: September 2017

ABSTRACTThe seismic damage of non‐structural components could involve functionality interruption of the most affected buildings and substantial economic losses. Among non‐structural components, the lightweight steel ceiling‐partition wall systems can represent a significant investment in the construction sector. Nevertheless, the proper seismic design of these systems plays a secondary role within the current structural design, by leading to a lack of specific design provisions. Since the behaviour of these systems cannot be easily simulated with traditional analysis methods, the experimental characterization is an effective procedure. For these reasons, a specific research activity was started over last few years at the University of Naples Federico. The main objective of the research is to investigate the seismic performance of lightweight steel drywall non‐structural building components, i.e. partition walls and suspended continuous ceilings made of lightweight steel profiles sheathed with gypsum‐based panels. The presented paper describes and discusses particularly the in‐plane quasi‐static reversed cyclic tests carried out on lightweight steel drywall partition walls. The obtained results could be considered a starting point for developing the in‐plane seismic design assisted by testing of lightweight steel drywall partition walls according to European prescriptions.