scholarly journals Creep-free fire analysis of steel structures with Eurocode 3 material model

2016 ◽  
Vol 7 (3) ◽  
pp. 234-248 ◽  
Author(s):  
Neno Toric ◽  
Rui Rui Sun ◽  
Ian W. Burgess
Keyword(s):  
Steel Structures ◽  
Material Model ◽  
Steel Beams ◽  
Heating Rates ◽  
Content Type ◽  
Simply Supported ◽  
Fire Engineering ◽  
Steel Members ◽  
Steel Material ◽  
Eurocode 3

Purpose This paper aims to propose a methodology to remove inherent implicit creep from the Eurocode 3 material model for steel and to present a creep-free analysis on simply supported steel members. Design/methodology/approach Most of the available material models of steel are based on transient coupon tests, which inherently include creep strain associated with particular heating rates and load ratios. Findings The creep-free analysis aims to reveal the influence of implicit creep by investigating the behaviour of simply supported steel beams and columns exposed to various heating regimes. The paper further evaluates the implicit consideration of creep in the Eurocode 3 steel material model. Originality/value A modified Eurocode 3 carbon steel material model for creep-free analysis is proposed for general structural fire engineering analysis.

scholarly journals PERFORMANCE OF DIFFERENT CREEP MODELS IN THE ANALYSIS OF FIRE EXPOSED STEEL MEMBERS

2016 ◽  
Author(s):  
Neno Torić ◽  
Rui Rui Sun ◽  
Ian W. Burgess
Keyword(s):  
Axial Compression ◽  
Steel Beams ◽  
Fire Tests ◽  
Heating Rates ◽  
Material Models ◽  
Simply Supported ◽  
Steel Members ◽  
Creep Models ◽  
In Fire ◽  
The Impact

In order to model the impact of the creep strains on the behaviour of steel in fire, several creep models have been implemented into <em>Vulcan</em> research code. The paper presents verifications of these creep models for fire-exposed steel against transient fire tests of simply supported steel beams with various loading arrangements, including bending combined with axial compression. In addition, a creep-free analysis of the fire tests has been performed using a newly developed creep-free methodology. Creep-free analysis is vital in explicit modelling of steel creep in fire, since most of the available material models of steel in fire were derived from transient coupon tests and inherently included creep associated with the particular heating rates used in the tests.

Seismic Tests of Welded Moment Resisting Connections Made of Laser-Welded Stainless Steel Sections

2018 ◽  
Vol 763 ◽  
pp. 440-449
Author(s):  
Hafez Taheri ◽  
George Charles Clifton ◽  
Ping Sha Dong ◽  
Michail Karpenko ◽  
Gary M. Raftery ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Large Scale ◽  
Steel Structures ◽  
Steel Beams ◽  
Steel Connections ◽  
Steel Members ◽  
Moment Resisting ◽  
Steel Sections ◽  
Seismic Tests

Steel structures are well established as the preferred material for constructing seismic resisting systems in New Zealand and around the world. While the majority of steel framing is made of carbon steel, stainless steel is increasingly being considered for designing exposed steel structures. Because of significant differences in the mechanical properties between the two materials, seismic resisting system design rules for connections between carbon steel members may not be applicable, at least without modification, to connections between stainless steel members. This study has investigated the seismic performance of welded T-shaped beam-column moment resisting connections made of structural stainless steel beams and columns manufactured by laser welding. The paper included the results of three large-scale T-shaped specimens, of varying sizes, subjected to seismic loads. The grade of laser-fused stainless steel was 304 L and its specification was according to ASTM A276. The sections were subject to the seismic tests in accordance with the SAC protocol given in ANSI/AISC 341-10. The results shows substantial amount of energy dissipation by welded moment resisting stainless steel connections along with a high ductility capability and dependable behaviour in the inelastic range.

Glued laminated timber and steel beams

2018 ◽  
Vol 16 (3) ◽  
pp. 398-417 ◽  
Author(s):  
Osama A.B. Hassan ◽  
Christopher Johansson
Keyword(s):  
Sustainable Development ◽  
Environmental Impact ◽  
Structural Design ◽  
Carbon Dioxide Emissions ◽  
Rectangular Cross Section ◽  
Steel Beams ◽  
Order Effects ◽  
Content Type ◽  
Glued Laminated Timber ◽  
Eurocode 3

Purpose This paper aims to compare glued laminated timber and steel beams with respect to structural design, manufacturing and assembly costs and the amount of greenhouse gas emissions. Design/methodology/approach This paper presents structural design requirements in conformance with EN 1993: Eurocode 5 and Eurocode 3. With the help of these standards, expressions are derived to evaluate the design criteria of the beams. Based on the results of life-cycle analysis, the economic properties and environmental impact of the two types of beam are investigated. In this paper, the effect of beam span on the design values, costs and carbon dioxide emissions is analysed when investigating aspects of the structural design, economy and environmental impact. Different cross-sections are chosen for this purpose. Findings The study shows that the glued laminated (abbreviated as “glulam”) beams have a smaller tendency to lateral torsional buckling than the steel beams, and that they can be cheaper. From an environmental point of view, glulam beams are the more environmentally friendly option of the two beam materials. Furthermore, glulam beams may have a direct positive effect on the environment, considering the carbon storage capacity of the wood. The disadvantage of glued wood is that larger dimensions are sometimes required. Research limitations/implications Wind load and the effect of second-order effects have not been considered when analysing the static design. Only straight beams have been studied. Furthermore, the dynamic design of the beams has not been investigated, and the bearing pressure capacity of the supports has not been analyzed. We have investigated timber beams with a rectangular cross-section, and steel beams of rolled I-sections, known as “HEA profiles”. The cost analysis is based mainly on the manufacturing and assembly costs prevalent on the Swedish market. The only environmental impact investigated has been the emission of greenhouse gases. The design calculations are based on the European standards Eurocode 5 and Eurocode 3. Practical implications To achieve sustainability in construction engineering, it is important to study the environmental and economic consequences of the building elements. By combining these two effects with the technical design of buildings made of steel and/or timber, the concept of sustainable development can be achieved in the long run. Social implications The study concerns sustainability of building structures, which is an important of the sustainable development of the society. Originality/value The paper contains new information and will be useful to researchers and civil engineers.

scholarly journals Application of Component-Based Mechanical Models and Artificial Intelligence to Bolted Beam-to-Column Connections

2021 ◽  
Vol 11 (5) ◽  
pp. 2297
Author(s):  
Iman Faridmehr ◽  
Mehdi Nikoo ◽  
Raffaele Pucinotti ◽  
Chiara Bedon
Keyword(s):  
Mechanical Performance ◽  
Input Parameter ◽  
Steel Structures ◽  
Steel Beams ◽  
Ann Model ◽  
Initial Stiffness ◽  
Moment Capacity ◽  
Bee Colony ◽  
Eurocode 3 ◽  
Mechanical Models

Top and seat beam-to-column connections are commonly designed to transfer gravitational loads of simply supported steel beams. Nevertheless, the flexural resistance characteristics of these type of connections should be properly taken into account for design, when a reliable analysis of semi-rigid steel structures is desired. In this research paper, different component-based mechanical models from Eurocode 3 (EC3) and a literature proposal (by Kong and Kim, 2017) are considered to evaluate the initial stiffness (Sj,ini) and ultimate moment capacity (Mn) of top-seat angle connections with double web angles (TSACWs). An optimized artificial neural network (ANN) model based on the artificial bee colony (ABC) algorithm is proposed in this paper to acquire an informational model from the available literature database of experimental test measurements on TSACWs. In order to evaluate the expected effect of each input parameter (such as the thickness of top flange cleat, the bolt size, etc.) on the mechanical performance and overall moment–rotation (M–θ) response of the selected connections, a sensitivity analysis is presented. The collected comparative results prove the potential of the optimized ANN approach for TSACWs, as well as its accuracy and reliability for the prediction of the characteristic (M–θ) features of similar joints. For most of the examined configurations, higher accuracy is found from the ANN estimates, compared to Eurocode 3- or Kong et al.-based formulations.

Effectiveness of CFRP composites on compression flange of structural I-beam

2019 ◽  
Vol 17 (4) ◽  
pp. 782-792
Author(s):  
Prashant Rangrao Jagtap ◽  
Sachin M. Pore
Keyword(s):  
Carrying Capacity ◽  
Steel Structures ◽  
Local Failure ◽  
Elastic Behavior ◽  
Steel Beams ◽  
Load Carrying Capacity ◽  
Content Type ◽  
Cfrp Laminates ◽  
Load Carrying ◽  
Strengthened Beam

Purpose This study aims to use carbon fiber-reinforced polymer (CFRP) laminates to strengthen the compression flange of structural I-beam so as to avoid local failure of compression flange and to take a load to its full capacity. Light weight beam (LB) 100 at 5.1 kg/m and LB 115 at 8.1 kg/m are used for this purpose. The compression flange of a beam is well prepared to ensure a rust-free surface so as to achieve proper bonding between the flange and fiber sheet to avoid de-bonding at the time of testing. A flange of the beam is strengthened using CFRP sheets applied to it with the help of adhesive. The beam with CFRP is cured in air for 48 h before testing. Experiments are performed in a loading frame of 100 T capacity. Results show that the load carrying capacity of the strengthened beam increased by 25-30 per cent compared to the control beam (non-strengthened), and the local failure of the compression flange due to the applied load is totally avoided. The elastic behavior of the strengthened beam is also increased compared to the non-strengthened beam, which gives a higher yield point. Design/methodology/approach Different methods exist for strengthening various structures. Use of CFRP appears to be an excellent solution. Vast research has been conducted on the use of CFRP for strengthening and retrofitting of steel structures. The load carrying capacities of steel beams can be increased by strengthening their compression flange by using CFRP and avoiding the local failure of beams at early stages. Findings The load carrying capacity of a beam strengthened with CFRP increased by 25-30 per cent compared to the non-strengthened beam. In addition, the elastic behavior of the strengthened beam is also improved. Originality/value The compression flange of the steel beam is strengthened using different layers of CFRP strips to avoid the local failure, and its deflection is observed using linear variable deformation transducer.

Effectiveness of damaged fireproofing in structural steel members subjected to fire

2019 ◽  
Vol 10 (1) ◽  
pp. 24-47 ◽  
Author(s):  
Ataollah Taghipour Anvari ◽  
Mustafa Mahamid ◽  
Michael McNallan ◽  
Mohammadreza Eslami
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Steel ◽  
Fire Resistance ◽  
Fire Protection ◽  
Steel Beams ◽  
Element Analysis ◽  
Content Type ◽  
Steel Members ◽  
Resistance Reduction

Purpose The purpose of this paper is to present the effect of damaged fireproofing on structural steel members. This study will show that a minor damage in fireproofing will reduce the fire rating of members significantly. Damaged fireproofing happens in structures due to various reasons, and the question is always how effective is this fireproofing? This paper presents the results of one type of fireproofing and presents a parametric study on the size of damage and its effect on fire resistance of structural steel members. Design/methodology/approach The study has been performed using numerical methods, thermal and structural finite element analysis. The analysis method has been verified by experimental results. Findings Small fire protection damage or loss leads to significant rise of temperature at the damaged parts and causes severe fire resistance reduction of beams. The higher fire protection damage’s extension at the bottom flange of the steel beams does not have any major influence on the rate of reduction of fire resistance of the beams. Steel beams experience greater fire resistance reduction at higher load levels because of the existing of higher stresses and loads within the steel beam section. Research limitations/implications The study has been performed using finite element analysis, and it covers a wide range of practical sizes. However, experimental work will be performed by the researchers when funding is granted. Practical implications The study provides researchers and practitioners with an estimate on the effect of damaged fireproofing on fire resistance of structural steel beams. Social implications Understanding the effect of the effect of damaged fireproofing helps in estimating the fire resistance of structural steel members, which may protect collapses and disasters. Originality/value The research is original; extensive literature review has been performed, and this research is original.

Strength of Class 3 steel W sections in weak axis bending

2007 ◽  
Vol 34 (4) ◽  
pp. 576-579
Author(s):  
Konstantin Ashkinadze
Keyword(s):  
Local Buckling ◽  
Steel Structures ◽  
Technical Note ◽  
Steel Beams ◽  
Limit States ◽  
Moment Capacity ◽  
Design Capacity ◽  
Section Modulus ◽  
Steel Members ◽  
Improved Design

This technical note considers weak axis moment capacity of wide-flange steel members of different section classes. In CSA S16-01 Limit states design of steel structures, there is a disconnect in moment capacity of laterally supported members between Classes 2 and 3: when the section crosses the Class 2 boundary, its calculated capacity drops in the ratio of the elastic to plastic section modulus. This effect is relatively minor for strong axis bending but is rather significant for weak axis bending. A rational theory is presented that explains the phenomena on the transition of the two Classes and proves that the noted gap in the design capacity does not exist. An improved design formula is proposed to mitigate this problem.Key words: bending, class, flange, local buckling, steel beams, strong axis, weak axis.

scholarly journals Experimental analysis and mechanical modeling of T-stubs with four bolts per row

2021 ◽  
Author(s):  
Massimo Latour ◽  
Gianvittorio Rizzano
Keyword(s):  
Steel Structures ◽  
Experimental Tests ◽  
Analytical Models ◽  
Fe Model ◽  
Yield Line ◽  
Collapse Mechanisms ◽  
Steel Members ◽  
Eurocode 3 ◽  
Set Up ◽  
Definition Of

The behavior of steel structures is significantly affected by the connections between the steel members. For this reason, special attention to the prediction of the joint rotational behavior is devoted by Eurocode 3 which provides the well-known component method. In EC3, starting from the results of several researches, the formulations for the characterization of the behavior of T-stubs with two bolts per row are given, but with reference to T-stubs with four bolts per row, even though they are present in many actual structural situations, the limited number of experimental tests and analytical models has not led yet to the codification of this component in the code. In this work, starting from the results of three experimental tests on T-stub with four bolts per row, carried out at the laboratory on materials and structures of the University of Coimbra, a FE model in ABAQUS has been set up in order to analyze the yield line patterns corresponding to the different collapse mechanisms. Subsequently, with reference to the yield line shape different from that of T-stub with two bolts per row, the effective lengths have been revaluated applying an energy approach. The definition of the effective width for all the possible collapse mechanisms allowed to set up a proposal for determining the resistance of T-stubs with 4 bolts per row consistent with the approach provided by Eurocode 3. The model accuracy has been verified by means of a comparison with the results provided by a numerical analysis.

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