New developments in the direct strength method (DSM) for the design of cold-formed steel sections under localised loading

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.

Download Full-text

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.201-203.2900 ◽

2011 ◽

Vol 201-203 ◽

pp. 2900-2903 ◽

Cited By ~ 5

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.

Download Full-text

ANALYTICAL STUDY OF BEHAVIOR OF COLD FORMED STEEL SECTIONS WITH AND WITHOUT PERFORATION UNDER COMPRESSIVE LOADING

International Journal of Engineering Applied Sciences and Technology ◽

10.33564/ijeast.2021.v05i09.024 ◽

2021 ◽

Vol 5 (9) ◽

Author(s):

Majahar M. Baraskar ◽

Pranil Shetake ◽

Prof. V. M Bogar ◽

Dr. Y. M Ghugal

Keyword(s):

Construction Industry ◽

Compressive Loading ◽

Weight Ratio ◽

High Strength ◽

Cross Sectional Area ◽

Sectional Area ◽

Cross Sectional ◽

Steel Sections ◽

Cold Formed Steel ◽

Lower Temperature

Steel is used in construction industry due to its hardness and tensile strength. Cold formed steel is type of steel which is manufactured at lower temperature. Cold form steel became more popular in twentieth century in construction industry due to its high strength to weight ratio and post-buckling strength. The purpose of this study is to study the behavior of cold-formed steel sections of different shapes but of same cross sectional area for compressive loading. Effect of lips within same cross sectional area, effect of perforation and shape stiffener is evaluated on different sections as channel section, Z section and hat section. Eigen value buckling analysis was carried out to on twelve different models to obtain the buckling load and failure pattern. ANSYS WORKBENCH software was used for numerical simulation of sections. I.S. 801:1975 has been taken under consideration wherever required. Based upon the results, optimum section in each of cases as with lips, without lips and perforated amongst all three sections is suggested. Effect of shape stiffeners provided by previous researcher P. Manikandan on solid sections is evaluated to check its suitability with perforated sections.

Download Full-text

Behaviour of cold-formed steel built-up I-section columns composed of four U-profiles

Advances in Structural Engineering ◽

10.1177/1369433218795568 ◽

2018 ◽

Vol 22 (3) ◽

pp. 613-625 ◽

Cited By ~ 5

Author(s):

M Anbarasu ◽

M Venkatesan

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Ultimate Strength ◽

Element Model ◽

Cross Sectional ◽

Direct Strength Method ◽

The North ◽

Compression Members ◽

Cross Sectional Dimension ◽

Cold Formed Steel

This work reports numerical results concerning the cold-formed steel built-up I-section columns composed of four U-profiles under axial compression. A finite element model is developed by using the software program ABAQUS. The developed model includes geometric, material nonlinearities and geometric imperfections. The finite element model was verified against the experimental results reported in the cold-formed steel built-up open section columns. In the parametric study, the sections are analysed with several cross-sectional dimension ratios and lengths, in order to assess their influence on the buckling behaviour and ultimate strength of cold-formed steel built-up I-section columns. After presenting and discussing the numerical parametric results, the article shows that the current direct strength method in the North American Specification for cold-formed steel compression members design curve fails to predict adequately the ultimate strength of some of the columns analysed and addresses the modification proposed on current direct strength method curves, providing improved predictions of all the numerical ultimate strength available. The proposed method is also assessed by reliability analysis.

Download Full-text