bluuebunny/crossref_metadata_2025_split huggingface dataset:
A proposal for the local stresses in retrofitted crane runway girders due to eccentric wheel loading
Authors: Kettler Markus , Unterweger Harald , Derler Christoph 
Published: September 2021

AbstractGenerally, the local stresses near the web‐flange connection represent one of the most decisive criteria for the fatigue design of steel crane runway girders, particularly because every crane wheel induces an individual stress cycle and fatigue failure can potentially occur at any position of the girder's length. This paper presents a crane runway girder made of steel that has been retrofitted in the past to reduce the local bending stresses in the web, because of the installation of a new, heavier crane. This was done by additional longitudinal stiffeners to form a boxed upper flange. The local vertical stresses in the girder's web are investigated numerically and experimentally and the influence of the subsequently attached reinforcement plates, forming a boxed upper flange, is studied. Traditionally, it is state of the art to neglect any local bending stresses in the web after retrofitting the upper flange area to get a local box section. The results presented in this paper indicate that the additional local bending stresses within the upper flange box section can be significant and should not be neglected for fatigue design. Therefore, a new design concept for the calculation of the local bending stresses in webs of retrofitted crane runway girders with new boxed upper flange is proposed.
Assessment of the Interaction Conditions of I‐shaped Cross‐Sections
Authors: Ludwig Christian 
Published: September 2021

AbstractIn this research, the interaction conditions for double‐symmetric I‐sections without fillets are analysed. Interaction conditions are necessary for the determination of plastic load‐bearing capacity, which is preferred over elastic load‐bearing capacity for economic reasons. In literature, standards and current research projects, different interaction conditions for My, Mz and Mω are available. However, analyses of their accuracy are missing. This research intends to determine the deviations of each interaction condition using numerical approaches. The interaction conditions are verified on the basis of extensive parameter studies. This study shows that the solutions available in EN 1993‐1‐1 and prEN 1993‐1‐1 lead to uneconomical results. Furthermore, for the application of the interaction condition according to EN 1993‐6 certain limits have to be considered to avoid a non‐conservative design. In this paper, the new extended exponent method is presented. This method is a simple, economical and conservative solution.
Large‐scale fatigue tests on thick walled circular hollow sections
Authors: Dürr André , Roth Jakob 
Published: September 2021

AbstractThe fatigue strength according to EN 1993‐1‐9 and other recommendations for the design of steel structures are generally determined by fatigue tests. Because of cost and time reasons fatigue tests are usually performed on small‐scale specimens. However, test results gained on these specimens with smaller dimensions cannot cover the influence of a possible size‐effect on the fatigue strength. For the transfer of the fatigue strength to real structures with larger dimensions and larger wall thicknesses additional large‐scale fatigue tests are required. At the University of Applied Sciences Munich, several large‐scale fatigue tests on thick walled circular hollow sections with welded K‐joints were performed in recent years. The large‐scale fatigue tests had dimensions similar real structures with lengths up to 18 m, weights up to overall 17 tons and wall thicknesses up to 60 mm. Within this paper, the used test bench for the large‐scale fatigue tests is described and the results are discussed regarding the influence of the size effect.
Fatigue durability of large‐sized trough rib ortho‐tropic steel deck for deck crack
Authors: Hirai Takahide , Saito Shiro , Sakano Masahiro 
Published: September 2021

AbstractA lot of fatigue cracks were reported in orthotropic steel deck (OSD) because the structure of OSD supported wheel load directly. Among them, many fatigue cracks at the intersections between trough rib and transverse rib were reported. Improved structures of the the intersections between trough rib and transverse rib were reported by many researchers. The purpose of this paper is to propose new structure of OSD that using Thread Rolling Screw at joint of trough rib and transverse rib instead of welding and confirming its fatigue durability by fatigue test. Two specimens were prepared. These differences are thickness of deck plate. After fatigue test, we drilled 40 mm diameter hole at upper deck surface and conducted magnetic particle testing to confirm development of deck crack. As a result, fatigue cracks developed at the connection between transverse rib and deck plate in existing structure while no fatigue cracks were detected in proposed structure.
Selecting Suitable Bolt Parameters to Achieve Ductility at Elevated Temperatures
Authors: Shaheen Mohamed A. , Foster Andrew S. J. , Cunningham Lee S. , Afshan Sheida 
Published: September 2021

AbstractA detailed FE study is presented investigating the factors affecting failure modes of bolt assemblies under tensile force at ambient and elevated temperatures. Axisymmetric FE models incorporating important behavioural aspects including surface interaction and damage modelling were developed. Stripping failure is generally undesirable because it results in premature failure of the bolt, which can deteriorate the rotational capacity of connections and robustness of steel frames. The paper discusses how the thread length in the grip Lt can affect the failure mode of bolt assemblies at elevated temperatures. This paper concludes that at ambient temperature, stripping can occur at certain Lt length dependent upon the nut dimension deviation from the basic profile; this length reduces with temperature.
DSM Design of Cold‐Formed Steel Columns Failing in Flexural‐Torsional Modes at Elevated Temperatures
Authors: Bicelli Antonio , Landesmann Alexandre , Camotim Dinar , Dinis Pedro 
Published: September 2021

AbstractThe purpose of this work is to extend the scope of the previous studies, by considering fixed‐ended columns under elevated temperatures (up to 800° C) with three cross‐section shapes (lipped channels, racks and stiffened lipped channels), various cross‐section dimensions (five per shape) and different lengths. The results presented and discussed consist of column FT post‐buckling equilibrium paths and failure loads, which are obtained through geometrically and materially non‐linear Ansys SFEA. In order to cover a wide FT slenderness range, several room‐temperature yield stresses are considered. The model prescribed in EC3‐1.2, for cold‐formed steel, is adopted to describe the temperature‐dependence of the steel material properties. Finally, the numerical failure loads obtained by the authors, together with numerical and experimental ones collected from the literature are used to propose a modification of the DSM‐based FT strength curves developed previously by authors and assess the merits of the new design curves. It is shown that the proposed modification improves visibly the failure load prediction quality, thus providing encouragement to continue the search for an efficient and reliable DSM‐based design approach for columns failing in FT modes at elevated temperatures.
Experimental study on rotational restraint provided by sandwich panels at elevated temperature
Authors: Horváth László , Joó Attila László , Lendvai Anita 
Published: September 2021

AbstractBy the wider spread of sandwich panels as a cladding system on industrial steel buildings, the research on various design aspects is evolving as well. The principal aim of the research introduced in this paper is to study the rotational restraint provided by sandwich panels at both ambient and elevated temperatures, and derive the temperature dependent rotational spring stiffnesses. In the frame of an ongoing international RFCS research program named STABFI, several experimental test series were carried out. This paper has a main focus on the part of the small scale tests, in which the rotational behavior of the screwed connection between sandwich panels with mineral wool core and H‐beam was investigated. The panel‐substructure connections were tested to define rotational stiffness at different inner panel sheet temperatures (20, 200, 250, 300, 450 and 600 C°). During testing the temperature of the inner sheet, the outer sheet, and the core of the sandwich panel were recorded. The applied torsional load at the axis of the connection and the rotation was measured and recorded, from which the moment‐rotation diagrams of the joints were derived. Based on these curves the temperature dependent rotational spring stiffnesses were also determined.
Experimental analysis of steel beams with fire resistant properties subjected to the ISO 834 Fire
Authors: Jordão Alexandre Magnus , Scabbia André Luiz Gonçalves , e Silva Valdir Pignatta 
Published: September 2021

AbstractAll buildings with human occupation need to be designed to withstand a certain standardized fire time related to the safety of their occupants. Within this context, the structure plays an extremely important role as passive fire protection element. As a result, the use of fire‐resistant steel has been produced and used to decrease the volume of passive protective material and sometimes eliminate it due to the presence of alloying elements such as niobium and molybdenum on its composition whose chemical synergy, coupled with carefully metallurgical processes, can maintain the material's mechanical properties above that those associated with the conventional steel. This paper is part of an extent research and aim to present initial experimental results of the behavior of no protected three side exposed beams under 60 minutes ISO 834 Fire curve with and without fire‐resistant properties. The tests were carried out into a horizontal furnace and the vertical deflection at the thirds of span was measured while the central was calculated based on these measurements. The experiment did not have the intention of investigate the connections, because of that, were stiffened for supporting the large plastic deformations of the specimen
Fire Testing of Grade 304 Stainless Steel Plate Material Under Transient‐state Conditions
Authors: Farmani Mohammad Amin , Du Xingchen , Heidarpour Amin , Zhao Xiao‐Ling 
Published: September 2021

AbstractOwing to its superior performance at high temperatures, stainless steel is usually considered as a potential replacement for mild steel in a wide range of structural fire engineering applications. When it comes to the fire design of steel structures, time‐dependent deformations occurring in the adequately‐heated steel material, called “thermal creep” need to be somehow considered in the design calculations. In EUROCODE 3‐1‐2, for example, the thermal creep strains are implicitly included in the transiently‐determined stress‐strain curves for steel at elevated temperatures. Using the same approach, this paper investigates the fire‐temperature mechanical properties of Grade 304 stainless steel by conducting transient tensile tests at temperatures of up to 900°C on standard coupons taken from a 3.0 mm thick plates. To simulate structural fire conditions in the transient tests, the temperature of the sample is steadily increased when a constant tensile load is applied. From these tests, strain‐temperature curves are obtained, wherein the strain contains both mechanical and thermal components. The strain‐temperature curves with the same heating rate of 10°C/min are then converted to elevated‐temperature stress‐strain curves suitable for fire design applications.
Fire design of composite beams and slabs: practical design considerations according to Eurocode 4
Authors: Pimentel Ricardo , Craveiro Helder , Simões Rui 
Published: September 2021

AbstractComposite slabs and beams are widely used in the construction market. The fire design is often required, which demands an assessment of materials' resistances at elevated temperature. The main topic of this article is to evaluate the impact of the temperature distribution in the concrete flange for the fire design of composite beams and slabs. The analytical design methodology proposed by Eurocode 4 will be implemented to a comprehensive number of examples, where different methods to address the slab temperature profile in the concrete flange are used. Practical advice for fire design and protection coating definition will be presented. Numerical Finite Element Model (FEM) analyses were used to support some of the conclusions.
Mechanical Properties and Resistance Coefficient of Carbon Steel during Fire
Authors: Murakawa Tomonori , Takahashi Yusuke , Imagawa Yusuke , Ohyama Osamu 
Published: September 2021

AbstractRecently, serious fire accidents have occurred on bridges. For example, the 9‐Mile Overpass located near Detroit, MI, USA, experienced serious damage, where the steel‐concrete composite girder bridge fell down. To avoid future instances of such events, we need to understand the effect of the decrease in hardness of carbon steel during fire on structural characteristics, and to clarify the collapse mechanism of a bridge. Fifty years ago, the Japan Society of Steel Construction (JSSC) defined the mechanical properties of carbon steel up to 900 °C. However, recently, there have been bridge fire incidents where the heat has exceeded an estimated 1000 °C. Therefore, it is necessary to conduct the high temperature tensile test above 900 °C. In Japan, the design method has changed from the allowable design method to the limited design method, and a fire design method for the safety, serviceability and restorability of bridges has not been established. In near future, we seek to clarify the resistance coefficient for fire design. Herein, we carry out the high temperature tensile test to determine the relationship between strength and temperature, and propose a resistance coefficient for fire design based on these results. The 1 % yield strength of SM400 (minimum tensile stress: 400 N/mm2) decreased on average by 26 % at 500 °C, and on average by 94 % at 1100 °C. It was found that the elongation of carbon steel is greatest at 800 °C.
Post‐fire behaviour of structural stainless steel
Authors: Molkens Tom , Cashell Katherine A. , Malaska Mikko , Alanen Mika , Rossi Barbara 
Published: September 2021

AbstractStainless steel offers excellent mechanical properties as well as corrosion resistance and performs better in a fire compared to carbon steel in that it retains its strength and stiffness for a longer duration. The current paper is focussed on the post‐fire condition, which has only received limited attention to date from the research community. The motivation for the work is to show that stainless steel elements which have been exposed to fire can be re‐instated with minimal additional costs in a short time frame. The paper proceeds with a description of recent material tests into the residual properties of grade 1.4301 austenitic stainless steel, following exposure to elevated temperature. Two different types of test are added to this available data. Firstly, a series of tensile tests are completed on coupons taken from a loaded stainless steel beam previously examined under fire conditions. Secondly, a set of virgin coupons (i.e. which have not been previously heated or tested) are exposed to different levels of elevated temperature and cooling procedures. This is with a view to understanding the ability of structural elements made from this material to survive a fire and continue in service. The results are then employed along with other data obtained from the literature to conduct a detailed study into the design considerations.
Numerical simulation of damage patterns in the plastic hinge area of fire protected (SFRM) steel beams and its effect on their fire resistance
Authors: Zografopoulou Kalliopi , Mistakidis Euripidis 
Published: September 2021

AbstractSprayed Fire‐Resistive Materials (SFRMs) are low strength, brittle materials used as passive fire protection on steel structural members. Their main drawback is that they can develop significant damage when the underlying steel member is subjected to mechanical deformations. The current study addresses numerically the damage patterns of the passive fire protection that could arise at the plastic hinge area of IPE steel beams and their effect on the fire resistance of the member. Initially, a numerical method that combines the smeared crack model and the discrete crack concept is implemented for the simulation of the mechanical behavior of the fire protective material and the prediction of the damage it sustains. The results of the mechanical analysis, considering the parameters of cross‐section height, SFRM thickness, monotonic or cyclic loading and presence of geometric initial imperfections, suggest that the damage pattern, which is a result of the combination of interface delamination and crack formation in the body of the material, can be categorized in two basic forms. In the sequel, a heat transfer analysis is conducted on the steel beams, under standard ISO‐834 thermal load, taking into account the damage derived by the mechanical analysis, in order to assess the reduction in the fire resistance of the beams, compared to the corresponding beams with an intact fire protection layer or without any fire protection.
The Role of Tendons for Fire Safety Design of Pre‐tensioned Steel Structures
Authors: Du Yong , Li Guo‐Qiang 
Published: September 2021

AbstractPre‐tensioned steel strands as basic elements have been widely used in hybrid string structures, suspended roofs and cable‐stayed bridges. When subjected to localised fire, the steel cables relaxes due to thermal expansion, reduction of mechanical properties as well as creep strain at elevated temperature. Meanwhile, the bond strength of anchors at each end of a steel cable decreases due to adhesive properties of filling material decreasing at elevated temperature. In this paper, a set of new formula was regressed to determine the full range of stress‐strain relationship, reduction factors of mechanical properties and creep strain of steel cables at elevated temperature. A special thermal transfer path considering of the cavity radiation among wires has been developed to determine the transient temperature distribution in the cross section of steel strands. Analytic method was developed to predict the temperature in the centre of hot‐cast anchors and temperature history of cold‐cast anchors at ISO834 fire was also investigated by ANSYS software. Thermo‐mechanical action of global pre‐tensioned steel structures was investigated by analytic and numerical simulation methods. The expertise and knowledge also provides insights to the fire safety design of pre‐tensioned steel structures.
An Experimental Study of the Effects of Crack and Detachment on Insulation Properties of Intumescent Coating
Authors: Wang Lingling , Wang Yongchang , Li Guoqiang 
Published: September 2021

AbstractThis paper presents the results of an experimental study to investigate the failure modes of intumescent coatings and their effects on temperatures attained in steel sections and load carrying capacities of steel columns. Primer and intumescent coatings were applied to unloaded steel plates, unloaded I‐shaped short sections and axially loaded I‐shaped long columns. For the axially loaded columns, three different surface treatments were considered. The failure modes of intumescent coatings include distributed fine cracking, discrete wide and deep cracking, and detachment. Distributed fine cracks appeared on the unloaded plate specimens. Discrete crack was the main failure mode on the unloaded steel sections. For the loaded long columns, the intumescent coating failure modes included both discrete crack and detachment. Intumescent coating failure affected the average temperatures attained, with average temperatures of the plate specimens, unloaded steel sections and loaded steel columns being 411°C, 472°C and 543°C respectively after 30 minutes of standard fire exposure. Different surface treatment does not seem to have much effect on fire resistance of the carbon steel columns, the two columns reaching fire resistance times of 38 and 39.5 minutes respectively.
Compression Tests on Large Angle Columns in High Strength Steel
Authors: Bezas Marios‐Zois , Demonceau Jean‐François , Vayas Ioannis , Jaspart Jean‐Pierre 
Published: September 2021

AbstractThe paper discusses the stability behaviour of large angle columns in high strength steel subjected to compression loads. It presents a number of compression tests on such columns that have been performed at University of Liege with different eccentricities and slenderness and, as a result, different buckling failure modes observed. The experimental campaign is intended to widen the knowledge about the behaviour of high strength steel columns with large angle sections in compression and bending and so to complement previous experimental studies. The tests have been accompanied by numerical analyses and calculations of the load carrying capacities through present Eurocode prescribed methods. The numerical simulations have been carried out by application of the FEM software FINELG using beam elements and considering of relevant imperfections as well as geometrical and material non – linearities. The numerical and analytical results are compared and validated with the corresponding experimental ones and summarized in the present paper. The experimental campaign and the numerical simulations are part of the European‐funded RFCS project ANGELHY “Innovative solutions for design and strengthening of telecommunications and transmission lattice towers using large angles from high strength steel and hybrid techniques of angles with FRP strips”.
Favourable Steel Structures using High Strength Steels
Authors: Gong Fengyan , Dürr André , Bartenbach Jochen 
Published: September 2021

AbstractAs a part of the European RFCS‐project STROBE, HOCHTIEF Engineering has developed a calculation programme as the basis of a web‐tool for the design and optimization of steel beams. The programme is suitable for steel girders of normal strength and for high strength girders up to S690 including welded hybrid girders. In this paper, the developed calculation programme as well as several case studies will be presented based on an existing project which compares the design of floor systems of conventional strength steel S355 with high strength steel floor systems. The benefits of solutions using modern high strength steels for sustainable construction relative to conventional strength steel S355 in terms of saving weight and costs will be highlighted.