Strength design curves and an effective width formula for cold-formed steel columns with distortional buckling

2014 ◽  
Vol 79 ◽  
pp. 62-70 ◽  
Author(s):  
Ziqi He ◽  
Xuhong Zhou
Keyword(s):  
Effective Width ◽  
Distortional Buckling ◽  
Steel Columns ◽  
Strength Design ◽  
Cold Formed Steel

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.

Lipped channel cold-formed steel columns under local-distortional buckling mode interaction

2019 ◽  
Vol 137 ◽  
pp. 251-270 ◽  
Author(s):  
Gustavo Y. Matsubara ◽  
Eduardo de M. Batista ◽  
Guilherme C. Salles
Keyword(s):  
Mode Interaction ◽  
Distortional Buckling ◽  
Buckling Mode ◽  
Steel Columns ◽  
Cold Formed Steel

On the direct strength design of cold-formed steel columns failing in local-distortional interactive modes

2017 ◽  
Vol 120 ◽  
pp. 432-445 ◽  
Author(s):  
André Dias Martins ◽  
Dinar Camotim ◽  
Pedro Borges Dinis
Keyword(s):  
Steel Columns ◽  
Strength Design ◽  
Cold Formed Steel

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.

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.

EWM-based design method for distortional buckling of cold-formed thin-walled lipped channel sections with holes

2022 ◽  
Vol 19 (1) ◽  
pp. 972-996
Author(s):  
Xingyou Yao ◽  
Keyword(s):  
Design Method ◽  
Effective Width ◽  
The Finite Element Method ◽  
Distortional Buckling ◽  
Buckling Strength ◽  
Channel Section ◽  
The North ◽  
Buckling Stress ◽  
Cold Formed Steel ◽  
Theoretical And Numerical Analysis

<abstract> <p>The distortional buckling is easy to occur for the cold-formed steel (CFS) lipped channel sections with holes. There is no design provision about effective width method (EWM) to predict the distortional buckling strength of CFS lipped channel sections with holes in China. His aim of this paper is to present an proposal of effective width method for the distortional buckling strength of CFS lipped channel sections with holes based on theoretical and numerical analysis on the partially stiffened element and CFS lipped channel section with holes. Firstly, the prediction methods for the distortional buckling stress and distortional buckling coefficients of CFS lipped channel sections with holes were developed based on the energy method and simplified rotation restrained stiffness. The accuracy of the proposed method for distortional buckling stress was verified by using the finite element method. Then the modified EWM was proposed to calculate the distortional buckling strength and the capacity of the interaction buckling of CFS lipped channel sections with holes based on the proposal of distortional buckling coefficient. Finally, comparisons on ultimate capacities of CFS lipped channel sections with holes of the calculated results by using the modified effective width method with 347 experimental results and 1598 numerical results indicated that the proposed EWM is reasonable and has a high accuracy and reliability for predicting the ultimate capacities of CFS lipped channel section with holes. Meanwhile, the predictions by the North America specification are slightly unconservative.</p> </abstract>

Load-Carrying Capacity Estimation Methods for Cold-Formed Steel Lipped Channel Member Using Effective Width Method

2010 ◽  
Vol 163-167 ◽  
pp. 90-101 ◽  
Author(s):  
Xing You Yao ◽  
Yuan Qi Li ◽  
Zu Yan Shen
Keyword(s):  
Steel Structures ◽  
Channel Member ◽  
Effective Width ◽  
Structural Members ◽  
Distortional Buckling ◽  
Plate Buckling ◽  
Load Carrying ◽  
Cold Formed Steel ◽  
Buckling Coefficient ◽  
Thin Walled

Distortional buckling may occur for Cold-formed thin-walled steel lipped channel member except local buckling and overall buckling. The buckling of flange and lip are the important factor for the occurrence the distortional buckling. The different design codes have different design method for calculating plate buckling coefficient of flange and lip using the effective width method. So the effective width method in different codes are introduced and the load-carrying capacities of 100 lipped channel section compressive members collected from reference are computed using ‘Cold-formed steel structures (AS/NZS 4600:2005)’, ‘Supplementary rules for cold-formed members and sheeting(EN1993-1-3:2006)’, ‘North American specification for the design of cold-formed steel Structural Members(AISI-S100:2007)’, ‘Specification for the design of cold-formed steel structural members (AISI:1996)’ and ‘Technical code of cold-formed thin-walled steel structures’(GB50018-2002). The calculated results show that ‘Technical code of cold-formed thin-walled steel structures (GB50018-2002)’ and ‘Supplementary rules for cold-formed members and sheeting (EN1993-1-3:2006)’ are conservative and ‘Cold-formed steel structures (AS/NZS 4600:2005)’, ‘North American specification for the design of cold-formed steel Structural Members (AISI-S100:2007)’ and ‘Specification for the design of cold-formed steel structural members (AISI:1996)’ are unsafe. The elastic buckling stress of different lipped channel sections are predicted by finite strip program (CUFSM) and get the suggested calculation formula of plate buckling coefficient of flange according to regression Analysis. The calculated results using suggested plate buckling coefficient of flange are agree to test results.

scholarly journals Behaviour of Cold Formed Built - Up Steel Compression Member

2019 ◽  
Vol 8 (4) ◽  
pp. 8409-8413
Keyword(s):  
Slenderness Ratio ◽  
Distortional Buckling ◽  
Cross Sectional ◽  
Buckling Modes ◽  
Steel Columns ◽  
Steel Members ◽  
Load Carrying ◽  
Cold Formed Steel ◽  
Ultimate Load Carrying Capacity ◽  
Sectional Shape

The use of cold-formed thin-walled steel structural members has increased in recent years. Especially, Cold-formed steel columns are widely used in the construction industry due to their lightweight, easy installation, erection and economy. The strength and efficiency of cold-formed steel profiles depends on the cross-sectional shape, which controls the three fundamental buckling modes: local, distortional and global. As most of their sections are open with only one symmetrical axis, they would likely fail by twisting and interacted with the other buckling modes such as local and distortional buckling. In order to improve the ultimate strength of columns, a built-up column section with distinct shape was selected from the detailed study of Literatures and three specimens of thickness 1.6mm were fabricated with different lengths 500mm, 600mm and 700mm. Consequently, buckling behaviour of built up steel members was investigated theoretically with Direct Strength Method (with the help of CuFSM) as well as experimentally and the results were compared with the buckling modes obtained numerically using ANSYS software and it is found that the ultimate load carrying capacity of the column increases with the decrease of slenderness ratio and finally a new innovative and economical column element was presented.

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