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.

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.

Limit states design of steel structures—performance factors

1980 ◽  
Vol 7 (1) ◽  
pp. 45-77 ◽  
Author(s):  
D. J. L. Kennedy ◽  
M. Gad Aly
Keyword(s):  
Slenderness Ratio ◽  
Steel Structures ◽  
Steel Beams ◽  
Limit States ◽  
Steel Columns ◽  
Performance Factors ◽  
Coefficients Of Variation ◽  
Detailed Statistical Analysis ◽  
Physical Tests ◽  
Hollow Structural Sections

A detailed statistical analysis to give ratios of mean to nominal values and associated coefficients of variation (based on raw data collected from Canadian mills on the strength and geometric properties of rolled W shapes, welded W shapes, and class H hollow structural sections) is presented. By relating the tested capacity (based on physical tests performed by others) to the predicted capacity (based on the design equations in CSA standard S16.1-1974, Steel Structures for Buildings—Limit States Design), the professional ratio and its associated coefficient of variation were determined for steel columns as a function of the slenderness ratio, as well as for laterally supported and laterally unsupported steel beams, enabling the performance factor to be determined for these members over the entire range of behaviour. A serviceability criterion for steel bridges is presented.

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.

Local buckling of Class 2 beam-column flanges

1993 ◽  
Vol 20 (6) ◽  
pp. 931-939 ◽  
Author(s):  
J. L. Dawe ◽  
T. S. Lee
Keyword(s):  
Key Words ◽  
Axial Load ◽  
Analytical Study ◽  
Local Buckling ◽  
Steel Structures ◽  
Experimental Results ◽  
Test Results ◽  
Limit States ◽  
Column Buckling ◽  
Compact Class

Test results are presented and discussed for 18 beam-column specimens subjected to flange local buckling resulting from applied axial and flexural forces. Flanges classified as Class 2 by CAN3-S16.1-M84 “Steel structures for buildings (limit states design)” are investigated. Three different sizes of W shape with different height and web thickness ratios within the Class 2 range were used in this investigation. The flange width-to-thickness ratio was kept constant at the current Class 2 limit [Formula: see text]. Results of this investigation show that the conventional value of plastic moment reduced in the presence of axial load, as based on studies in the late 1950s, does not apply to Class 2 sections. This discrepancy had previously been predicted by an analytical study using an extended Rayleigh–Ritz technique and presented in 1980. Experimental results presented herein verify these predictions. Key words: axial, beam-column, buckling, compact, Class 2, interaction, slenderness.

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.

Resistance factors for laterally unsupported steel beams and biaxially loaded steel beam columns

1984 ◽  
Vol 11 (4) ◽  
pp. 1008-1019 ◽  
Author(s):  
Karen A. Baker ◽  
D. J. Laurie Kennedy
Keyword(s):  
Key Words ◽  
Steel Structures ◽  
Resistance Factor ◽  
Steel Beams ◽  
Steel Beam ◽  
Limit States ◽  
Beam Columns ◽  
Resistance Factors ◽  
Design Resistance

Data from 30 tests conducted on laterally unsupported steel beams, and 148 tests on biaxially loaded steel beam columns conducted by others are statistically analyzed to determine resistance factors appropriate for use with the design equations given in CSA Standard CAN3-S16.1-M84 (Steel structures for buildings—limit states design). The general value of 0.90 currently given in that standard for the resistance factor is shown to be conservative by 1 –6% for both laterally unsupported beams and biaxially loaded beam columns. Key words: beam columns, beams, biaxially loaded, laterally unsupported, limit states design, resistance factors, steel.

Behaviour of partly stiffened cold-formed steel built-up beams: Experimental investigation and numerical validation

2018 ◽  
Vol 22 (1) ◽  
pp. 172-186 ◽  
Author(s):  
M Adil Dar ◽  
N Subramanian ◽  
A R Dar ◽  
M Anbarasu ◽  
James BP Lim ◽  
...  
Keyword(s):  
Failure Modes ◽  
Numerical Study ◽  
Local Buckling ◽  
Steel Structures ◽  
Vital Role ◽  
Steel Beams ◽  
Design Strength ◽  
Finite Element Software ◽  
Cold Formed Steel ◽  
Reserve Strength

To address the various instability problems in cold-formed steel members, many researchers have mainly focused on developing innovative sectional profiles wherein geometry of the section plays a vital role in enhancing the inherent resistance of such sections against premature buckling. However, the process of forming such innovative shapes is not only complex and time-consuming but sometimes such sections fail to mobilize their complete reserve strength. Hence, a stiffening arrangement of weaker zones for mobilizing the untapped reserve strength is suggested. The contribution of this simple, effective and partly stiffening arrangements, aimed at eliminating/delaying the premature local buckling, is studied both experimentally and numerically and also compared with existing codes. Experimental study was carried out on different simply supported cold-formed steel beams with judiciously proposed stiffening arrangements under four-point loading. An equivalent hot-rolled steel beam was also tested to compare the efficiency of the cold-formed steel beams. The cold-formed steel beams investigated had different width-to-thickness ratio, different geometries and different stiffening arrangements. The test strengths, failure modes, deformed shapes, load versus mid-span displacements and geometric imperfections were measured and reported. The test strengths of the beam models are also compared with the design strength predicted by North American Standards and Eurocode for cold-formed steel structures. To validate the test results further, a numerical study was carried out on such stiffened cold-formed steel beams using finite element software ABAQUS. All these results show that the proposed strengthening system is efficient and economical and allow cold-formed steel beams to reach greater load carrying capacity.

Experimental Investigation on Cold-formed Steel Beams under Pure Bending

2012 ◽  
pp. 13-20 ◽  
Author(s):  
Yeong Huei Lee ◽  
Yee Ling Lee ◽  
Cher Siang Tan
Keyword(s):  
Local Buckling ◽  
Bending Moment ◽  
Steel Beams ◽  
Pure Bending ◽  
Lateral Instability ◽  
Moment Capacity ◽  
British Standard ◽  
Cold Formed Steel ◽  
The Moment ◽  
Design Yield

This paper presents the flexural behaviour of cold-formed double lipped channels beams under pure bending action. Two channel sections are bolted back-to-back to form an I-shape structural beam member. A series of six experiment tests were carried out on beam specimens DC200 and DC250, each with 200 mm depth and 250 mm depth respectively. The thickness of beam section is 2 mm and the design yield strength is 350 N/mm2. All beams failed at local buckling at top-flange due to lateral instability of the cold-formed steel structural members. The moment resistance for DC200 is 17.87 kNm and DC250 is 31.53 kNm. The experimental results are compared to theoretical resistance prediction based on British Standard and Eurocode. The comparison showed that the experimental moment capacity is lower than the theoretical bending moment resistance but higher than theoretical buckling moment resistance from Eurocode. This showed that a better agreement is achieved between experimental data and Eurocode buckling moment resistance for cold-formed steel beam under pure bending. Kertas kerja ini membentangkan sifat lenturan rasuk keluli tergelek sejuk di bawah tindakan lenturan tulen. Dua channel dihimpunkan berkembar dan diperketatkan dengan bolt untuk membentuk rasuk struktur bentuk-I. Satu siri ujian lenturan telah dijalankan ke atas spesimen rasuk DC200 dan DC250, dengan kedalaman 200 mm dan 250 mm masing-masing. Ketebalan keratan rasuk adalah 2 mm dan kekuatan reka bentuk adalah 350 N/mm2. Semua rasuk gagal pada momen kilasan sisi di bahagian atas bebibir akibat ketakstabilan sisi anggota keluli tergelek sejuk. Rintangan momen bagi DC200 adalah 17.87 kNm dan DC250 adalah 31.53 kNm. Keputusan eksperimen dibanding dengan ramalan teori yang berdasarkan British Standard dan Eurocodes. Perbandingan tersebut menunjukkan bahawa rintangan momen lenturan eksperimen adalah lebih rendah daripada ramalan teori momen lenturan tetapi lebih tinggi daripada ramalan teori momen rintangan kilasan sisi mengikut Eurocode. Ini menunjukkan bahawa persetujuan baik dicapai di antara keputusan eksperimen dengan ramalan teori Eurocode momen rintangan kilasan sisi bagi rasuk keluli tergelek sejuk.

Built-Up Cold-Formed Steel Beams with Corrugated Webs Connected with Spot Welding

2015 ◽  
Vol 1111 ◽  
pp. 157-162 ◽  
Author(s):  
Ştefan Benzar ◽  
Viorel Ungureanu ◽  
Dan Dubină ◽  
Mircea Burcă
Keyword(s):  
Spot Welding ◽  
Local Buckling ◽  
Steel Beams ◽  
Steel Buildings ◽  
Moment Capacity ◽  
Steel Sheets ◽  
Beam Depth ◽  
Steel Sections ◽  
Cold Formed Steel ◽  
The Web

Corrugated web girders emerged in the past two decades. Their main advantages consists in the possibility to use slender webs avoiding the risk of premature local buckling. Consequently, higher moment capacity might be obtained increasing the beam depth with really thin webs, which are stiffened by the corrugations. Increased interest for this solution was observed for the main frames of single-storey steel buildings and steel bridges. A new solution was proposed at the Politehnica University of Timisoara, in which the beam is composed by a web of trapezoidal steel sheet and flanges of back-to-back lipped channel steel sections. This solution uses self-drilling screws for connecting flanges to the web and to ensure the continuity of the web as seam fasteners. Starting from this new technological solution the paper extends and investigates the use of spot welding as seam fastening to build the web, in order to increase the degree of automation of fabrication. Experimental work of specimens in shear having two or three layers of steel sheets connected by spot welding will be presented. The results will be implemented on a numerical model in order to study the behaviour of the beams presented above.

Buckling Behavior of Circular Steel Tubes under Fire

2018 ◽  
Vol 763 ◽  
pp. 270-278
Author(s):  
Ji Hye Seo ◽  
Deok Hee Won ◽  
Woo Sun Park ◽  
Seung Jun Kim
Keyword(s):  
Fire Resistance ◽  
Local Buckling ◽  
Steel Structure ◽  
Steel Structures ◽  
Steel Tube ◽  
Elastic Buckling ◽  
Element Analysis ◽  
Steel Members ◽  
Buckling Behavior ◽  
Circular Steel Tube

Recently, several lives were lost because of the collapse of structures under fire. Steel members are mainly used in the columns and beams of buildings for improving construction efficiency. The fire resistance of steel structure is very important because when it don’t have fire resistive covering, it rapidly changes with high temperature. In fire resistance design of steel, steel structure must have fire resistive covering. But many facilities as temporary facilities, parking lot don’t have it. The buckling behavior of steel structures under fire is also significant because it can cause local buckling failure through the reduction in structural material properties by temperature. In this study, the elastic buckling behavior of a circular steel tube under fire was investigated using finite element analysis. The parameters for this analysis used were, diameter–thickness ratio, fire exposure area, and fire scenarios. The elastic buckling strength of circular steel tube rapidly decreased when subjected to the fire curve. Local buckling occurred and this can lead to global failure. When fire resistance design of circular steel tube was performed, buckling behavior must be considered.

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