bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analytical model for the prediction of the plastic shear resistance of the panel zone in welded joints
Authors: Corman Adrien , Demonceau Jean‐François , Jaspart Jean‐Pierre 
Published: September 2021

AbstractThis article addresses the problem of prediction of the plastic shear resistance of the panel zone (PZ) in welded steel beam‐to‐column joints under monotonic loading. Existing analytical models are first critically reviewed through comparisons with available experimental data. These comparisons reveal that none of them is able to accurately capture all the complex phenomena governing the plastic shear resistance of the PZ. Therefore, a new analytical model is developed based on the extensive use of finite element (FE) analysis. This approach includes the development and validation of a FE model within the Abaqus environment and the use of the so‐validated model in order to perform a parametric study on (non‐)axially loaded (un‐)stiffened interior and exterior joint configurations. This parametric study helps to gain a better understanding of the actual distributions of stresses within the PZ. Based on these observations, a new analytical model is proposed and validated against the numerical results. This model proves to work well and to outperform existing analytical models by providing a more coherent estimation of the plastic shear resistance of the PZ.
European traffic on road bridges and recalibration of damage equivalence factor for fatigue verification
Authors: Bianchi Gianluca , Nussbaumer Alain , Pedro José J. Oliveira 
Published: September 2021

AbstractThe evolution of European traffic, combined with the current revision works of the Eurocodes (CEN250 project 2nd Eurocode generation), represents an opportunity to improve the simplified method for fatigue checks (also known as the lambda method) for road bridges. The works reported herein focus on the reassessment of the λ1 factor curves for the damage effect of highway traffic on road bridges, using the existing Eurocode FLM3 model. The aim of the research is to model the traffic and resulting stress ranges at details on bridges with different static systems. The simulation results shall be as similar as possible to reality by introducing different parameters that were not taken into account in the EN 1993‐2 background simulations [1, 2], including the passage of multiple vehicles at the same time in the flowing and congested traffic conditions. The development of new λ1 factor curves lead to a different classification into midspan bending moment, shear force, and support midspan and shear force. Within this study, the validity of the formulas for λ2 and λ3 were also checked. The new curves have less dispersion and may be taken into consideration to update the current curves from EN 1993‐2.
Deep Learning based method for the prediction of the buckling resistance of SHS and RHS
Authors: Toffolon Andrea , Kraus Michael A. , Taras Andreas 
Published: September 2021

AbstractThis paper proposes a data‐driven and deep learning based model for the prediction of the buckling load of square and rectangular hollow sections (SHS and RHS) based on Finite Element Method (FEM) results of the local buckling effects. The data was elaborated during the EU‐funded research project – HOLLOSSTAB (2016‐2019), where a new design method – termed the “Generalized Slenderness‐based Resistance Method” (GSRM) ‐ was developed, aiming to simplify through a unified analytical approach time consuming computational analyses for the prediction of the local resistance of SHS and RHS. This method further generalizes the concepts of established design methods such as the Direct Strength Method. This paper investigates an alternative approach to the development of design rules for this same mechanical problem: the application of deep learning models for the prediction of the buckling load through simple input parameters, such as geometric quantities, material values and applied load to circumvent the application of the analytical formulae. Thereby, a Deep Neural Network (DNN) model is created and calibrated for the prediction of the buckling loads of SHS and RHS based on the training data given by the extensive FEM parametric study. A statistical evaluation in accordance with EN1990 elaborates a partial safety factor for the proposed DNN. The predictions from the DNN are then compared to the numerical results from FEM analyses and to the predictions of the GSRM and EC3. Since the numerical results were originally validated against large scale experimental tests, this newly developed DNN makes use of a very large set of very representative (numerical) tests. A further comparison assesses the computed partial safety factor and the related quantities of interest for the DNN to the respective counterparts of the GSRM method. This work represents one of the first steps for the development of design methods in the field structural design adopting the most recent advances in computer sciences, and future enhancements of the currently developed models are discussed and proposed as a conclusion.
FE Model Validation and Advanced Analyses of Steel Members with Steel Claddings at Elevated Temperatures
Authors: Ma Zhongcheng , Havula Jarmo , Joo Attila , Lendvai Anita 
Published: September 2021

AbstractIn order to investigate the stabilization effect of distinct steel members by steel cladding system including trapezoidal sheeting and sandwich panels in fire using advanced analysis techniques, the computer models and modeling techniques must be validated by available experiment tests. However, the fire tests in this area are scarce. As part of a wider validation scheme, this paper presents the modeling method using Ls Dyna explicit solver and the comparison of FE analysis results with four experimental tests at elevated low to medium temperatures (150‐300 °C) in RFCS STABFI project. After the model validation, the advanced fire analyses of steel columns with two types of steel claddings such as trapezoidal sheeting and sandwich panel are carried out to investigate the stabilization effect. The analyses show that for the studied I‐section column under both axial compression and bending moment, the position of steel claddings, either connecting with the tension flange or the compression flange, has significant influence on the fire resistance of the steel columns. When the trapezoidal sheet is connected with the compression flange, the fire resistance of steel column is 17 % more than that without cladding. Sandwich panel cladding has influences on the deformational behavior of column during the fire exposure. However, the contribution of sandwich panels to the fire resistance of steel columns is negligible due to the delamination of inner panel sheet.
Structural Fire Analysis of One‐storey Steel‐framed Buildings with Steel Claddings
Authors: Ma Zhongcheng , Havula Jarmo , Mela Kristo , Kesti Jyrki 
Published: September 2021

AbstractTraditionally the structural stability of steel building frames is ensured by frame action or bracing elements. Recent European research projects have demonstrated that significant cost savings can be achieved, if cladding panels forming the building envelope are used to provide stability. The purpose of the paper is to investigate the possible stabilization effect of steel structures by steel claddings in fire, without additional wind bracings using Finite Element Method. The Finite Element analyses for full‐scale steel‐framed buildings with steel claddings under fires are still challenging due to large number of elements in the steel claddings. In this paper, the equivalent orthotropic shell element is used to model the trapezoidal roof sheeting, and composite shell element with soft core is used to model the sandwich panel in the cool compartment. Due to the delamination of inner steel face in fire, the sandwich panels in the fire compartment can be either neglected or modeled with two‐layer composite shell ignoring the inner steel sheet. The comparative study is performed, and the results suggest that the difference is small and the sandwich panels in the fire compartment can be neglected. The stabilization effect of steel claddings in fire is studied by the comparison of deformation and force responses between buildings with traditional steel bracings and with steel cladding only. In case of ISO fire, the fire resistance of entire one‐storey building with steel claddings only is 22% longer than the one with traditional steel bracings.
Deformations of steel end‐plate beam‐to‐column joint when subject to simulated steady‐state and transient‐state fire heating regimes
Authors: Maslak Mariusz , Pazdanowski Michal 
Published: September 2021

AbstractThe bearing capacity and rigidity of selected steel end‐plate beam‐to‐column joint are analysed in the paper. Those properties are determined numerically, based on the fire conditions simulated for this node. For comparison, two alternative heating regimes, typical for steady‐state and transient‐state scenarios, are considered. In the first case, an initially statically preloaded joint is evenly heated up to a predetermined temperature and subsequently, in this temperature, subjected to monotonously increasing static load until reaching the ultimate bearing capacity. In the second scenario, the same joint, subjected to the same preliminary static load, is subsequently statically loaded to reach a predetermined ratio of its ultimate bearing capacity and then, during the time of simulated fire, monotonously heated until failure. During the analysis it is assumed, that the steel is heated at a low rate, not affecting its material properties at given temperature. A cluster of curves depicted in the bending moment vs. effective rotation angle system of coordinates is a result of the first analysis. Each of these curves corresponds to a selected steel temperature. In the second case, the deformability of the joint, increasing with temperature, is expressed by a set of relationships between joint rotation and the corresponding temperature of steel. Thus a single relationship of this type corresponds to a selected level of external load applied at the node.
Numerical investigation of instabilities of steel members restrained by sandwich panels at elevated temperature
Authors: Lendvai Anita , Joó Attila László 
Published: September 2021

AbstractSandwich panel constructions are getting popular from the second half of the 20th century however, the restraint provided by sandwich panels in regards to the instability of structural members was not investigated at elevated temperature, which became the scope of the research introduced in this paper. An experimental test series was conducted at the Department of Structural Engineering at the Budapest University of Technology and Economics in order to study the stability behavior of structural members restrained by sandwich panels at ambient and elevated temperature. In this paper 18 tests are introduced, in which centrally located HEA120 sections of a 3.00 m x 3.00 m sized supporting sandwich panel diaphragm were tested for axial compression. The results indicate, that the decrease in load bearing capacity of PIR panels is higher, that in the case of mineral wool panels. The data derived from experimental tests were used for developing a complex numerical model. The primary objective of this paper is the comparison of numerical results with the results derived from experimental testing. This research has been financially supported by the European Union, in the frame of the Research Fund of Coal and Steel (RFCS) program. The authors gratefully acknowledge the support.
Numerical analysis of the torsional and flexural‐torsional buckling behaviour of compressed steel members at elevated temperature
Authors: Possidente Luca , Tondini Nicola , Battini Jean‐Marc 
Published: September 2021

AbstractSteel angle sections are frequently employed in bracing systems or in truss structures as single members or as built‐up members. Angles may be coupled back‐to‐back to create Tee or cruciform cross‐sections. These sections may be sensitive to torsional and flexural‐torsional buckling due to the cross‐section shape and the fact that the axial force may not be applied at the shear centre. In this work, a comprehensive numerical investigation of the behaviour of compressed angles, T and cruciform steel cross‐sections at elevated temperature was performed. A parametric study was carried out on Class 1 to 3 profiles subjected to uniform temperature distribution. Several numerical finite element analyses were carried out by varying the slenderness, the cross section, the steel grade and steel temperature employing beam and shell finite elements. It was found that the buckling curve given in the European structural code for steel structures in fire, i.e. EN 1993‐1‐2, provided results, that may not be conservative for a large slenderness range of practical interest, 0.4 ≤ λθ ≤ 1.5. Based on the results, adapted buckling curves were proposed to better predict the behaviour of angles, T and cruciform compressed cross‐sections at elevated temperature.
Fire performance of connections between high‐strength steel tubular members
Authors: McCann Finian , Wang Di 
Published: September 2021

AbstractAn investigation is conducted into the behaviour of bolted endplate connections between high‐strength steel tubular members at elevated temperatures. Experiments are described where assemblies comprising Grade S460 steel square hollow sections connected via bolted endplates are heated to a target temperature between 150°C and 750°C using ceramic heating pads. The assembly, which is inclined at 45° to the horizontal, is then loaded vertically, thus generating combined bending and axial thrust in the members. The in‐plane vertical deflection, the applied load and temperatures at various points were measured. Results for the ultimate loads, equilibrium paths and the observed failure modes are discussed along with the influence of temperature on these features. A complementary nonlinear finite element analysis of the experimental assemblies is also described. Material models incorporating temperature‐dependent strengths, stiffnesses and strain hardening relationships available from the literature are employed, with temperature fields calibrated using steel temperatures recorded during the experiments applied to the models. It is shown that good agreement exists between the ultimate loads, equilibrium paths and failure modes predicted by the numerical models and those observed in the experiments, thus validating the modelling approach. It is found that, at lower temperatures, buckling of the endplate was the governing mode of failure. With increasing temperature, the mode of failure transitions to flexure in the beam and column stubs, thus suggesting that a relative degree of fixity is offered by the connections at the higher temperatures.
Timber encasement of steel structures as an alternative fire insulation
Authors: Bihina Gisèle , Durif Sébastien , Bouchaïr Abdelhamid , Saulnier Véronique , Zhao Bin 
Published: September 2021

AbstractThis paper presents the results of an investigation on the thermal behaviour of fire‐exposed steel profiles embedded in timber elements.Several tests were performed on small unloaded specimens in a small furnace. The different specimens were made of bare steel profiles, timber elements or steel‐timber hybrid members. Different welded I or T steel sections and wood species were used. The specimens were set horizontally (3‐side exposure) or vertically (4‐side exposure) in the furnace and heated using a couple of burners. The temperatures of the steel profiles were measured by welded K thermocouples.The results from this experimental campaign, in terms of temperature of the furnace and of the specimens, density and moisture content of timber, were then used to calibrate a heat transfer model under Ansys finite element code. This 2D numerical model is mainly based on the behaviour laws of structural steel and timber from Eurocodes 3 and 5 respectively. Regarding the specific heat of timber, several relationships were applied. A comparative analysis of experimental and numerical results confirms the fire insulation brought to steel by timber. It also highlights the ability of the model to simulate the thermal behaviour of both steel and timber, in terms of heating and charring rates.
Multi‐scale bolt connection model for thermomechanical simulations
Authors: Xu Qingfeng , Hofmeyer Hèrm , Maljaars Johan 
Published: September 2021

AbstractA multi‐scale simulation approach is proposed to predict the fire resistance of structures comprising connections by bolts, as a supplement to an existing two‐way coupled CFD‐FEM method. In the existing model, fire is modelled by CFD, and its effects on the overall structure are found via thermodynamic and thermomechanical models. In this paper, detailed thermomechanical models are presented to predict the behaviour of a bolt connection, in order to find the equivalent linear elastic stiffness for the bolt connection that is modelled as a spring in the overall structure. Each load step, the stiffness of the spring is determined by the detailed model, which for a certain temperature, boundary conditions, and load type, predicts the connection behaviour, including geometric and material non‐linearity and failure. It will be shown that the detailed model simulates existing experiments for elevated temperatures well, and is able to predict all possible failure modes as listed in the Eurocode for ambient temperatures. It is then demonstrated that the model can also be used for all these failure modes for elevated temperatures. In the near future, a strategy will be developed to include the detailed models in the overall structure, within the two‐way coupled CFD‐FEM method.
Shallow composite floor beams – Proposal of a simplified analytical method for standard fire rating
Authors: Zanon Riccardo , Yildiz Sevilay , Obiala Renata , Braun Matthias 
Published: September 2021

AbstractShallow composite floor beams are a widely accepted solution for office, residential and other types of buildings. In most of their applications a standard fire resistance between R30 to R120 is required. Several fire tests were carried out in different laboratories over the last decades with various structural configurations, showing that this structural solution exhibits an integrated fire resistance without additional fire protection. In the frame of various programs, extensive research has been done on the fire behavior, completed by numerical simulations. Several scientists have proposed analytical methods to assess the resistance. Nevertheless, the Eurocode does not contain a method for assessing the standard fire resistance of composite shallow floor beams. This paper presents a simplified analytical method to determine the sagging moment resistance of Slim Floor Beams (SFB – being composed by a rolled section (or equivalent) with a wider plate welded below the bottom flange) under standard fire exposure. First, an FE model has been developed and validated on experimental tests. Afterwards, a parametric study covering various geometrical configurations and material choices has been performed. An analytical model for determining the sagging moment resistance is proposed and validated by comparison with results obtained by numerical simulation.
Behavior of Composite Floor Assemblies Subject to Fire: Influence of Slab Reinforcement
Authors: Choe Lisa , Ramesh Selvarajah , Zhang Chao , Clifton Charles 
Published: September 2021

AbstractA series of fire experiments are being conducted on the 2‐story steel framed building with composite floors in the National Fire Research Laboratory. This paper presents a brief overview of experimental design and discusses some results of the first test conducted on 6.1 m by 9.1 m composite floor assembly exposed to a standard fire. The test floor slab was constructed with lightweight concrete cast on 7.7 cm deep formed steel deck units and welded wire fabric (60 mm/m2) as the minimum shrinkage reinforcement required in the U.S. practice. The structural steel beams and girders were sprayed with a cementitious fire resistive material for a 2‐hour restrained fire resistance rating. While the test floor assembly resisted mechanical loads (2.7 kN/m2) applied using hydraulic actuators, its underside was exposed to a natural gas‐fueled compartment fire that was equivalent to the standard gas temperature‐time relationship. The study revealed that the test floor assembly could withstand an imposed load at a large vertical deflection on the order of span / 16, but the concrete slab failed due to limited ductility and strength prior to 2 hours in a standard fire. Simple post‐test predictions were performed incorporating tensile membrane action in the floor slab to compare with the measured behavior. Limited comparisons discuss the contribution of steel decking and slab reinforcement to the load‐carrying capacity of a floor assembly in fire.
Mechanical Properties of Steel–Concrete Composite Girder Subjected to Thermal History due to Fire
Authors: Takahashi Yusuke , Imagawa Yusuke , Ohyama Osamu 
Published: September 2021

AbstractFire damage to bridges occurs frequently in Japan and in other countries. Previous bridge fire accidents suggest that it is important to understand the structural performance of bridges after their exposure to fire. The Japan Society of Civil Engineering has proposed guidelines for the diagnosis and repair of steel bridges that have been exposed to fire. This guideline shows that the judgement temperature of steel members is 400°C. This temperature was established based on previous bridge fire accident reports and material testing after fire. It is unclear if the basis for evaluation has been the structural members. Therefore, it is necessary to clarify the effect of the rigidity reduction on the structural performance and judgement temperature of steel girder bridges after fire. The authors have studied the mechanical properties of steel–concrete composite girders as a medium span bridge before and after fire. A fire test was carried out to clarify the temperature distribution of the steel–concrete composite girder and static loading tests before and after fire were conducted to confirm the effect of the rigidity reduction from the fire. This study considers the validity of the judgment temperature from the test results.
Experimental and Numerical Investigations on Steel Columns Compartment Subjected to Travelling Fires
Authors: Nadjai Ali , Alam Naveed , Charlier Marion , McGillighan James , Vassart Olivier 
Published: September 2021

AbstractIn the frame of the European RFCS TRAFIR project, three large compartment fire tests involving steel structure were conducted by Ulster University, aiming at understanding in which conditions a travelling fire develops, as well as how it behaves and impacts the surrounding structure. During the experimental programme, the path and geometry of the travelling fire was studied and temperatures, heat fluxes and spread rates were measured. Influence of the travelling fire on the structural elements was also monitored during the travelling fire tests. This paper provides details related to the influence of travelling fires on structural steel columns. The experimental data is presented in terms of the gas temperatures recorded in the test compartment near the column, as well as the temperatures recorded in the steel column at different levels. The scope of the experimental work is extended using CFD simulations with FDS software, which demonstrate with good agreement with measurements in the steel column exposed to travelling fires.