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

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.

1984 ◽  
Vol 11 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Robert Loov

Load tests were carried out on 36 stub column samples of cold-formed steel studs having 38.1 mm wide × 44.5 mm long holes punched through their webs, steel thicknesses of 1.21–2.01 mm, and overall section depths of 63–204 mm. Based on these tests a best-fit equation for the effective width of the unstiffened portion of the web beside the holes has been developed. Suggested design equations have been proposed. The test results support the present equation for the average yield stress [Formula: see text] in Canadian Standards Association Standard S136-1974 but the present code equations for unstiffened plates are unduly conservative when applied to the design of the web adjacent to openings of the size considered.


2018 ◽  
Vol 1146 ◽  
pp. 142-151
Author(s):  
Viorel Ungureanu ◽  
Ioan Both ◽  
Mircea Burca ◽  
Ştefan Benzar ◽  
Thai Hoang Nguyen ◽  
...  

Within the WELLFORMED research project, ongoing at the CEMSIG Research Center of the Politehnica University of Timisoara, a new technological solution was proposed for built-up beams made of corrugated steel sheets for the web and thin-walled cold-formed steel profiles for the flanges, connected by spot welding. The research project integrates an extensive experimental program on such beams, using full scale specimens, to demonstrate the feasibility of the proposed solutions and to assess their performance, followed by numerical simulations to characterize and optimize the connecting details. The present paper presents the results of a large experimental program, on small specimens subjected to shear, consisting of two or three layers of steel sheet connected by spot welding.


2015 ◽  
Vol 74 (4) ◽  
Author(s):  
Ker Shin Mu ◽  
Poi Ngian Shek ◽  
Arizu Sulaiman ◽  
Boon Cheik Tan

This paper presents a parametric study on compound cold-formed steel sections as flexural members. The compound members are used to sustain higher load and solve the problems of local buckling and lateral torsional buckling. The aim of this study is to investigate the strength of compound cold-formed steel section subjected to pure bending. Moment capacity of the compound section is calculated in accordance to Eurocode 3. The compound cold-formed steel sections proposed in this study are made up of two cold-formed steel C-section and hot-rolled plates. Steel plates with thickness of 3 mm to 8 mm are added to the cold-formed double C-section with the purpose to increase the bending capacity. From the comparison, moment capacity of compound sections give higher value as compared to cold-formed steel C-section with the comparison ratios range between 1.15 and 3.30. Results from the study show that compound cold-formed steel sections able to enhance the strength in resisting pure bending by adding steel plate at the flanges and web of the section. On the other hand, finite element modeling using ANSYS is carried out on two of the selected compound cold-formed steel sections and the results show good agreement with analytical results.


2019 ◽  
Vol 950 ◽  
pp. 85-89
Author(s):  
Adeline Ling Ying Ng ◽  
Zhi Yong Law

A series of connection with screw fasteners were tested to study the behavior of cold-formed steel moment connection. The test specimens included hot-rolled parallel flange channels, cold-formed lipped C-Channels, and self-drilling self-fastening screws. Two different lipped C-Channels and a various number of screws per connection were used in this study. The moment-rotation behavior, rotational rigidity, and the connection capacity differed with the number of screws. The connection behaved as a pinned connection when 4 screws were used. However, local buckling was observed in the cold-formed steel sections near the connection when 8, 10 and 14 screws were used. The connection test results were compared with theoretical results calculated in accordance to the Australian Standards. None of the connection tested could achieve the moment capacity of the section connected.


Author(s):  
Viorel Ungureanu ◽  
Ivan Lukačević ◽  
Ioan Both ◽  
Mircea Burca

<p>Built-up cold-formed steel elements are efficient structural elements, very attractive due to material savings, but also for ease of construction. The connection between the built-up beam components can be easily obtained by screws, but the developments in the welding process also led to other solutions like spot welding. The WELLFORMED research project, conducted within the CEMSIG Research Center of the Politehnica University of Timisoara, proposes to study a new technological solution for built-up beams made of corrugated steel sheets for the web and thin-walled cold-formed steel profiles for the flanges, connected by spot welding. Within the research project, the experimental work included tensile-shear tests on the lap joint welded specimens, where different combinations of steel sheets with various thicknesses were tested and, tests on two full-scale beams in bending. The paper briefly summarizes the results of the experimental program and extends the research by numerical analyses to demonstrate the potential of this solution for standardization and industrial manufacturing. Based on the validation of the numerical model, the paper presents the influence of several parameters i.e.: (1) the initial imperfections, (2) the number and distance between spot welding on flanges, (3) the thickness of the flanges, (4) the thickness of the corrugated web and (5) the thickness of the shear panel. From the parametric study, it results that the bearing capacity of the corrugated web beams made of cold-formed steel components is highly affected by the stability of the components and less affected by the configuration and the number of spot welding.</p>


2012 ◽  
pp. 13-20 ◽  
Author(s):  
Yeong Huei Lee ◽  
Yee Ling Lee ◽  
Cher Siang Tan

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.


Author(s):  
Viorel Ungureanu ◽  
Ioan Both ◽  
Mircea Burca ◽  
Marius Grosan ◽  
Calin Neagu ◽  
...  

The WELLFORMED research project, ongoing at the CEMSIG Research Center of the Politehnica University of Timisoara, proposes to study a new technological solution for built-up beams made of corrugated steel sheets for the web and thin-walled cold-formed steel profiles for the flanges, connected by resistance spot welding. Within the research project, the experimental work includes tensile-shear tests on the lap joint spot-welded specimens, were different combinations of steel sheets with various thicknesses were tested and, tests on full scale beams in bending. The study intends to demonstrate the feasibility of the proposed solutions, to assess their performance and to enlarge the knowledge by using numerical simulations for the optimization of the current solution and to define the limits of the solution’s applicability.


2018 ◽  
Vol 26 (4) ◽  
pp. 331-344 ◽  
Author(s):  
Hayder Wafi Ali Al-Thabhawee ◽  
Muslim Abdul-Ameer Al-Kannoon

Castellated steel beams are those members which are made from hot rolled steel I-section firstly by cutting the web in zigzag pattern and rejoining the two halves by welding together to form a hexagonal castellated beam such that the depth of section will be increased. Generally, the openings made in the web are with hexagonal shape; however, octagonal shape of web openings is typically obtained by providing spacer plate which is utilized to increase the depth of beam. Nowadays, using castellated beams in building construction becomes very popular because of their useful functions such as ease of service provision, strength and low cost. This study focuses on improving the behavior of hexagonal and octagonal castellated beam with spacer plate. The ultimate strength of the original (parent) I- section beam increases due to the increasing its depth. The increment of castellated beam depth; however, leads to post buckling in its web and to many other modes of failure when these beams are subjected for loading. Hexagonal and octagonal castellated beams which are fabricated using parent I-section (IPN140) are analyzed using finite element model (FEM).The analysis results revealed that using ring stiffeners around edge of holes contributes effectively in strengthening the web. It was found that using ring steel stiffeners can reduce the stress concentration around the edge of holes and improve the behavior of these beams by increasing the ultimate strength and minimizing the deflection. From the numerical (FEM) results obtained by using ANSYS14, it is concluded that ultimate strength of castellated beam can be improved by providing spacer plate and ring stiffeners around the web hole. Also, the results showed that ultimate strength of octagonal castellated steel beam can be increased up to (53%) more than the parent beam (IPN140) with providing only (13.0%) weight of steel (spacer plate plus ring steel stiffeners).


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