Local buckling capacity of C-shaped cold-formed steel sections with punched webs

1984 ◽  
Vol 11 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Robert Loov
Keyword(s):  
Local Buckling ◽  
Effective Width ◽  
Test Results ◽  
Average Yield ◽  
Steel Sections ◽  
Load Tests ◽  
Cold Formed Steel ◽  
Stub Column ◽  
Best Fit ◽  
The Web

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.

scholarly journals Compression Test on Cold-Formed Steel Built-Up Back-to-Back Channels Stub Columns

2011 ◽  
Vol 201-203 ◽  
pp. 2900-2903 ◽  
Author(s):  
Chui Huon Tina Ting ◽  
Hieng Ho Lau
Keyword(s):  
Compression Test ◽  
Failure Modes ◽  
Local Buckling ◽  
Effective Width ◽  
Test Results ◽  
Direct Strength Method ◽  
Cold Formed Steel ◽  
Stub Column ◽  
Hot Rolled ◽  
Stub Columns

Built-up sections are used to resist load induced in a structure when a single section is not sufficient to carry the design load for example roof trusses. In current North American Specification, the provision has been substantially taken from research in hot-rolled built-up members connected with bolts or welds [1]. The aim of this paper is to investigate on built-up back-to-back channels stub columns experimentally and theoretically using Effective Width Method and Direct Strength Method. Compression test was performed on 5 lipped channel and 5 back-to-back channels stub columns fabricated from cold-formed steel sheets of 1.2mm thicknesses. The test results indicated that local buckling is the dominant failure modes of stub columns. Therefore, Effective Width Method predicts the capacity of stub columns compared to Direct Strength Method. When compared to the average test results, results based on EWM are 5% higher while results based on DSM are 12% higher for stub column.

Load capacity of uniformly compressed cold-formed steel section with punched web

1987 ◽  
Vol 14 (4) ◽  
pp. 550-558 ◽  
Author(s):  
K.S. Sivakumaran
Keyword(s):  
Load Capacity ◽  
Local Buckling ◽  
Iron And Steel ◽  
Out Of Plane ◽  
Steel Sections ◽  
Load Tests ◽  
Cold Formed Steel ◽  
Experimental Values ◽  
Stub Column ◽  
Effective Design

Load tests were carried out on 48 stub column specimens of cold-formed steel sections having flat widths of 82.5 and 144.7 mm, thicknesses of 1.60 and 1.29 mm, respectively, and various sizes and shapes of holes punched through their webs. This paper summarizes the experimental local buckling loads, ultimate loads, load–axial shortening relationships, and load–out-of-plane deflection relationships of the above specimens. Presently, the Canadian design code does not include any provisions in regards to the design of perforated cold-formed sections, owing to the lack of experimental results. A design approach using the present code "effective design width" for unstiffened elements is explored and the observations resulting from the comparison between the calculated values and the experimental values are given. The new American Iron and Steel Institute design specification gives an effective design width for cold-formed section with circular perforations. The appropriateness of this equation when applied to circular, square, and elongated openings is discussed. It appears that the design provisions of both codes are inadequate for the design of perforated cold-formed steel sections and further research is needed in this area. This is essential, considering the fact that, in practice, the cold-formed members often contain prepunched holes. Key words: axial load, buckling, building codes, cold-formed steel, effective design width, perforation, ultimate loads.

Comparison on Section Properties and Flexural Behaviour for Cold-Formed Steel Built-Up Section

2015 ◽  
Vol 735 ◽  
pp. 80-84 ◽  
Author(s):  
Yeong Huei Lee ◽  
Shahrin Mohammad ◽  
Yee Ling Lee
Keyword(s):  
Experimental Study ◽  
Local Buckling ◽  
Effective Width ◽  
Sectional Area ◽  
Flexural Behaviour ◽  
Distortional Buckling ◽  
Steel Sections ◽  
Cold Formed Steel ◽  
Flexural Resistance ◽  
Good Agreement

This paper performs analytical and experimental investigation on the section properties of locally produced cold-formed steel sections. Effective width method given by BS EN1993-1-3 is used to calculate the section properties for two slender cold-formed steel channel sections, namely KS200C20 and KS250C20. Local buckling and distortional buckling are taken into account in the calculation. Effective width method has significantly reduced the full sectional area and thus gives a relative lower value for the sectional resistance of cold-formed steel channel sections. The analytical results is compared to manufacturer’s data and differences of not more than 3.37% is recorded. Experimental study on the flexural behaviour on the two types of cold-formed steel channel sections is carried out. The results show that BS EN1993-1-3 has good agreement with experimental results for flexural resistance that included local and distortional buckling consideration. It is concluded that effective width method by BS EN1993-1-3 is suitable to calculate the section properties of of locally produced cold-formed steel channel sections.

Experimental Study of Cold-Formed Steel Moment Connections with Screw Fasteners

2019 ◽  
Vol 950 ◽  
pp. 85-89
Author(s):  
Adeline Ling Ying Ng ◽  
Zhi Yong Law
Keyword(s):  
Local Buckling ◽  
Test Results ◽  
Moment Connections ◽  
Moment Capacity ◽  
Moment Connection ◽  
Steel Moment Connection ◽  
Steel Sections ◽  
Cold Formed Steel ◽  
The Moment ◽  
Hot Rolled

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.

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.

scholarly journals Experimental Study and Effective Width Method for Cold-Formed Steel Lipped Channel Stud Columns with Holes

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Yanli Guo ◽  
Xingyou Yao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Ultimate Strength ◽  
Local Buckling ◽  
Effective Width ◽  
Element Analysis ◽  
Large Hole ◽  
The Finite Element Analysis ◽  
Cold Formed Steel ◽  
The Web

The objective of this paper is to investigate the buckling behavior and to present the design method of the ultimate strength in the basic effective width method (EWM) for cold-formed steel (CFS) lipped channel stud columns with holes in the web. 28 column tests were conducted under axial compression on the CFS lipped channel stud columns with circular and rectangular holes in different dimensions of cross sections and holes. The tested stud columns included 4 members without holes, 12 members with circular holes, and 12 members with rectangular holes. The test results showed that the stud columns with holes were governed by local buckling or the interaction of local buckling and distortional buckling. Compared with the stud columns without holes, the small hole had a slight influence on the ultimate strength of the tested specimens, and the large hole had a great effect on the ultimate strength of the tested specimens. The load capacities of the specimens decreased with the increase of the dimension of holes. Then, the finite element analysis was carried out to simulate the tested stud columns. The finite element analysis results showed good agreement with the experimental results about buckling modes and ultimate strengths, which indicated that it is feasible to analyze this kind of stud columns with holes by using the finite element method (FEM). Finally, the proposed effective width method was used to predict the ultimate strengths of stud columns with holes based on the proposed buckling coefficient formulas of the plate with holes. The comparison between calculated results and test and finite element results indicated that the proposed EWM is feasible and accurate to predict the ultimate strength of the CFS lipped channel stud columns with holes in the web.

scholarly journals Experiment and Design Method on Cold-Formed Thin-Walled Steel Lipped Channel Columns with Slotted Web Holes Under Axial Compression

2017 ◽  
Vol 11 (1) ◽  
pp. 244-257 ◽  
Author(s):  
Xingyou Yao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Ultimate Strength ◽  
Test Results ◽  
Distortional Buckling ◽  
Steel Columns ◽  
Cold Formed Steel ◽  
Thin Walled ◽  
Shell Finite Element ◽  
The Web

Background: Cold-formed steel structural sections used in the walls of residential buildings and agricultural facilities are commonly C-shaped sections with web holes. These holes located in the web of sections can alter the elastic stiffness and the ultimate strength of a structural member. The objective of this paper is to study the buckling mode and load-carrying capacity of cold-formed thin-walled steel column with slotted web holes. Methods: Compression tests were conducted on 26 intermediate length columns with and without holes. The tested compressive members included four different kinds of holes. For each specimen, a shell finite element Eigen-buckling analysis and nonlinear analysis were also conducted. The influence of the slotted web hole on local and distortional buckling response had also been studied. The comparison on ultimate strength between test results and calculated results using Chinese cold-formed steel specification GB50018-2002, North American cold-formed steel specification AISI S100-2016, and nonlinear Finite Element method was made. Result: Test results showed that the distortional buckling occurred for intermediate columns with slotted holes and the ultimate strength of columns with holes was less than that of columns without holes. The ultimate strength of columns decreased with the increase in transverse width of hole in the cross-section of member. The Finite element analysis results showed that the web holes could influence on the elastic buckling stress of columns. The shell finite element could be used to model the buckling modes and analysis the ultimate strength of members with slotted web holes. The calculated ultimate strength shows that results predicted with AISI S100-2016 and analyzed using finite element method are close to test results. The calculated results using Chinese code are higher than the test results because Chinese code has no provision to calculate the ultimate strength of members with slotted web holes. Conclusion: The calculated method for cold-formed thin-walled steel columns with slotted web holes are proposed based on effective width method in Chinese code. The results calculated using the proposed method show good agreement with test results and can be used in engineering design for some specific cold-formed steel columns with slotted web holes studied in this paper.

Axial Ultimate Capacity of Partially Encased Composite Columns

2012 ◽  
Vol 166-169 ◽  
pp. 292-295 ◽  
Author(s):  
Gen Tian Zhao ◽  
Chao Feng
Keyword(s):  
Peak Load ◽  
Local Buckling ◽  
Test Results ◽  
Remarkable Effect ◽  
Composite Columns ◽  
Axial Capacity ◽  
Stub Column ◽  
Partially Encased Composite Columns ◽  
Steel Section ◽  
Comprehensive Study

The test results of nine stub-column tests performed on partially encased composite (PEC) columns made with welded H-section steel are described and presented. The H-section steel is stiffened with transverse link and concrete is poured between the flanges of the steel section. The axial comprehensive study has been conducted on all specimens to investigate the ultimate axial capacity of PEC columns. The failure of all columns is due to local buckling of the flanges along with concrete crushing. Closer link spacing improves the ductility of the columns; however, the measurements show that in general yielding do not occur before the peak load in the links. The additional longitudinal bars have no a remarkable effect to the strength of the composite columns. Finally, an equation is proposed to predict the ultimate axial capacity of the partially encased composite column.

scholarly journals Experimental Study and Proposal to Improve the EWM Design of Cold-Formed Steel Lipped Channel Columns with Circular Holes under Axial Compression

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Xingyou Yao
Keyword(s):  
Circular Hole ◽  
Axial Compression ◽  
Design Method ◽  
Local Buckling ◽  
Effective Width ◽  
Distortional Buckling ◽  
Channel Section ◽  
Circular Holes ◽  
Failure Loads ◽  
Cold Formed Steel

The cold-formed steel (CFS) lipped channel section with circular holes has been widely used in low-rise and multistory building structures as the column. However, the circular hole in the web makes the lipped channel column become susceptible to buckle. A total of 54 CFS lipped channel axial compression columns with and without circular holes were used to study the buckling behavior and the effective width design method. The interaction of the local buckling and the distortional buckling were observed for the short and intermediate columns, while the slender columns were controlled by the interaction of the local buckling, distortional buckling, and flexural buckling or flexural-torsional buckling. The experimental failure loads were gradually decreased with the increase in the diameter of the circular hole for the specimens with the same section. The failure loads of the specimens with two holes were lower than those of the specimens with one hole with same section and same diameter of holes. Then, the experimental results were used to validate a nonlinear finite element model (FEM) previously developed by the authors. The validated FEM was subsequently used to obtain additional 36 numerical failure results concerning the effects of the length, the section, and the diameter and the number of the circular holes. Furthermore, the proposal to calculate the distortional buckling coefficient of the CFS lipped channel section with circular holes were put forward based on numerical analysis considering the reduction of effect of holes. Finally, a proposal to improve the effective width method (EWM) design approach for CFS lipped channel sections with circular holes under axial compression was presented. The comparisons between experimental and numerical capacities and their calculations provided by the proposed EWM design method illustrate a great application of the proposed approach.

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