Statistical analysis of fire tests on steel beams and columns to Eurocode 3, Part 1.2

1995 ◽  
Vol 33 (1-2) ◽  
pp. 39-50 ◽  
Author(s):  
J. Janss
2012 ◽  
Vol 18 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Zdeněk Kala

The random load carrying capacity of steel plane frames with bracing stiffness is studied. The load carrying capacity is evaluated using the geometrically non-linear FEM analysis. The incremental stiffness matrix of a slightly curved element utilized in the non-linear incremental analysis is listed. Initial imperfections are considered as random variables. Statistical analysis and Sobol sensitivity analysis are performed using the Latin Hypercube Sampling method. The effect of initial random imperfections on the load carrying capacity is studied, whilst assuming constant slenderness of the columns. The evaluation parameters are the pair of non-random values of elastic bracing stiffness, and system length of the columns. The paper illustrates that the load carrying capacity is very sensitive to initial crookedness of the columns in the event that the non-sway (symmetric) and sway (anti-symmetric) buckling modes coincide. In this case, the design load carrying capacity obtained from statistical analysis according to the EN 1990 (2002) standard is relatively very small (of low safety). Results show that the reliability of design of a steel frame according to EUROCODE 3 (1993) is significantly misaligned. The significance of the first and the second buckling forces as indicators of sensitivity of the load carrying capacity to the imperfections is discussed. Santrauka Tiriama plieninio plokščio rėmo su standžiaisiais ryšiais laikomoji galia. Ji vertinama atliekant geometriškai netiesinę BEM analizę. Aptariama šiek tiek išlinkusio elemento laipsniškai didėjanti standumo matrica, atliekant netiesinį iteracinį skaičiavimą. Atsitiktiniu dydžiu laikomas pradinis defektas. Statistinė ir Sobolio (Sobol) jautrumo analizė atliekama pritaikant LHS metodą (Latin Hypercube Sampling Method). Nagrinėjamas pradinio atsitiktinio defekto poveikis laikomajai galiai darant prielaidą, kad pastovus dydis yra liauna kolona. Vertinimo kriterijus yra ne atsitiktinių didžių pora, t. y. tampriai standus ryšiai ir konstrukcijos kolonų aukštis. Straipsnyje aptariama kolonos pradinio kreivio įtaka laikomajai galiai, atsižvelgiant į klupumo formas, kai nelinksta (simetrinė apkrova) ir linksta (nesimetrinė apkrova). Laikomosios galios projektavimo apkrovos, šiuo atveju gautos iš statistinės analizės pagal EN 1990 (2002) standartą, yra palyginti nedidelės. Gauti rezultatai rodo, kad plieninio rėmo patikimumas pagal Eurocode 3 (1993) labai nesutampa. Nagrinėjama defektų įtaka laikomajai galiai atsižvelgiant į pirmą ir antrą klupimo jėgą.


2017 ◽  
Vol 172 ◽  
pp. 665-672 ◽  
Author(s):  
Marek Łukomski ◽  
Piotr Turkowski ◽  
Paweł Roszkowski ◽  
Bartłomiej Papis

2021 ◽  
Author(s):  
A. Guardiola-Víllora ◽  
A. Pérez-García ◽  
A. Pérez

The Basic Document, Structural Safety, Steel of the Spanish Technical Building Code provides mathematical expressions to obtain the lateral buckling resistance of hot-rolled steel beams. These expressions include a coefficient, C1, that accounts for variation of the bending moment along the beam. However, this document only provides values for linear diagrams of bending moments. The instruction for Structural Steel, a copy of the latest version of Eurocode 3, does not include any method to obtain the elastic critical moment. On the contrary, a table with correction factors applicable to different types of bending moments diagrams is included. In this document both procedures have been combined and results have been compared to those obtained using other versions of the Eurocode 3. Finally, tables have been provided to ease the design of hot-rolled steel beams while preventing the lateral buckling.


2019 ◽  
Vol 11 (1) ◽  
pp. 1-10
Author(s):  
Andrej Mudrov ◽  
Gintas Šaučiuvėnas ◽  
Antanas Šapalas

The article investigates analytical models for calculation of tension capacity of axially-loaded RHS end-plate joints bolted along two and four sides of the tube in order to investigate the phenomena of prying. Design of such joints is impeded by lack of rules in EN 1993-1-8 and it raises the question whether the Eurocode 3 equivalent T-stub in the tension component should contain integrated assumptions from the AISC/CIDECT/CISC design guides. This paper considers the effect of the bolt hole on the length of the plastic hinge and compares different T-stub models with various assumptions. The behaviour and collapse mechanism of joints with non-preloaded and preloaded bolts was tested during an experiment. The statistical analysis of the test results of 47 joints found in the literature in conjunction with 7 tests determined that it was preferable to use a common approach for connections bolted along two and four sides. Additionally, a limitation of a minimum flange thickness is specified. The performed research has disclosed the benefits and shortcomings of the T-stub models and justified recommendations for their improvement.


2016 ◽  
Vol 7 (3) ◽  
pp. 234-248 ◽  
Author(s):  
Neno Toric ◽  
Rui Rui Sun ◽  
Ian W. Burgess

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.


2018 ◽  
Vol 16 (3) ◽  
pp. 398-417 ◽  
Author(s):  
Osama A.B. Hassan ◽  
Christopher Johansson

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.


2021 ◽  
Vol 11 (5) ◽  
pp. 2297
Author(s):  
Iman Faridmehr ◽  
Mehdi Nikoo ◽  
Raffaele Pucinotti ◽  
Chiara Bedon

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.


1976 ◽  
Vol 3 (2) ◽  
pp. 219-228 ◽  
Author(s):  
T. Z. Harmathy

A new numerical technique is described by which the process of creep bending under transient heating conditions can be predicted. It utilizes a convenient creep model, proposed by Dorn and expanded by this author.The computer simulation of the behavior of three protected steel beams during standard fire tests is discussed. The close agreement between the experimental and computed midspan deflection histories is regarded as the proof for the accuracy of the technique as well as of the creep model employed.


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