Cold-Formed Steel Structures

1997 ◽  
Author(s):  
Wei-Wen Yu
Keyword(s):  
Steel Structures ◽  
Cold Formed Steel

Design optimisation for cold-formed steel residential roof truss using genetic algorithm

2018 ◽  
Vol 15 (5) ◽  
pp. 575-583
Author(s):  
Ka Yee Kok ◽  
Hieng Ho Lau ◽  
Thanh Duoc Phan ◽  
TIina Chui Huon Ting
Keyword(s):  
Genetic Algorithm ◽  
Industrial Application ◽  
Steel Structures ◽  
Single Type ◽  
Efficient Design ◽  
Design Optimisation ◽  
Content Type ◽  
Roof Truss ◽  
Cold Formed Steel ◽  
Multi Level

Purpose This paper aims to present the design optimisation using genetic algorithm (GA) to achieve the highest strength to weight (S/W) ratio, for cold-formed steel residential roof truss. Design/methodology/approach The GA developed in this research simultaneously optimises roof pitch, truss configurations, joint coordinates and applied loading of typical dual-pitched symmetrical residential roof truss. The residential roof truss was considered with incremental uniform distributed loading, in both gravitational and uplift directions. The structural analyses of trusses were executed in this GA using finite element toolbox. The ultimate strength and serviceability of trusses were checked through the design formulation implemented in GA, according to the Australian standard, AS/NZS 4600 Cold-formed Steel Structures. Findings An optimum double-Fink roof truss which possess highest S/W ratio using GA was determined, with optimum roof pitch of 15°. The optimised roof truss is suitable for industrial application with its higher S/W ratio and cost-effectiveness. The combined methodology of multi-level optimisation and simultaneous optimisation developed in this research could determine optimum roof truss with consistent S/W ratio, although with huge GA search space. Research limitations/implications The sizing of roof truss member is not optimised in this paper. Only single type of cold-formed steel section is used throughout the whole optimisation. The design of truss connection is not considered in this paper. The corresponding connection costs are not included in the proposed optimisation. Practical implications The optimum roof truss presented in this paper is suitable for industrial application with higher S/W ratio and lower cost, in either gravitational or uplift loading configurations. Originality/value This research demonstrates the approaches in combining multi-level optimisation and simultaneous optimisation to handle large number of variables and hence executed an efficient design optimisation. The GA designed in this research determines the optimum residential roof truss with highest S/W ratio, instead of lightest truss weight in previous studies.

Mechanical Properties Prediction for Cold-formed Steel Angle Connection with Various Flange Cleat Thickness

2015 ◽  
Vol 74 (4) ◽  
Author(s):  
Yeong Huei Lee ◽  
Cher Siang Tan ◽  
Shahrin Mohammad ◽  
Yee Ling Lee
Keyword(s):  
Mechanical Properties ◽  
Numerical Models ◽  
Steel Structures ◽  
Rotational Stiffness ◽  
Steel Angle ◽  
Cold Formed Steel ◽  
Mechanical Properties Prediction ◽  
Thin Walled ◽  
Angle Connection ◽  
Hot Rolled

Connection is an important element in structural steelwork construction. Eurocode does not provide adequate design information for mechanical properties prediction of top-seat flange cleat connection, especially for thin-walled cold-formed steel structures. Adopting hot-rolled design with neglecting thin-walled behaviour could lead to unsafe or uneconomic design. This research aims to provide accurate mechanical properties prediction for bolted top-seat flange cleat connection in cold-formed steel structures. The scope of work focuses on the effect of various thickness of the flange cleat to the rotational stiffness and strength behaviour of a beam-to-column connection. Experimentally verified and validated finite element modelling technique is applied in the parametric investigation. Two categories of flange cleat thickness, ranged from 2 mm to 40 mm are studied. From the developed numerical models, it is observed that Eurocode has overestimated the initial rotational stiffness prediction, calculated with component method. The over-estimation would influence the overall stiffness of structures and force distribution within the components. As a conclusion, a set of newly proposed accurate predictions for initial rotational stiffness and strength of cold-formed steel top-seat flange cleat connection, with the influence of the thickness of flange cleat is presented.

Shake table tests of three storey cold-formed steel structures with strap-braced walls

2019 ◽  
Vol 17 (7) ◽  
pp. 4217-4245 ◽  
Author(s):  
Luigi Fiorino ◽  
Bianca Bucciero ◽  
Raffaele Landolfo
Keyword(s):  
Steel Structures ◽  
Shake Table ◽  
Shake Table Tests ◽  
Cold Formed Steel

scholarly journals Review on Cold-Formed Steel Connections

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Yeong Huei Lee ◽  
Cher Siang Tan ◽  
Shahrin Mohammad ◽  
Mahmood Md Tahir ◽  
Poi Ngian Shek
Keyword(s):  
Structural Characteristics ◽  
Steel Structures ◽  
Rolled Steel ◽  
Steel Connections ◽  
Steel Framing ◽  
Steel Sections ◽  
Cold Formed Steel ◽  
Hot Rolled ◽  
Hot Rolled Steel ◽  
Review Current

The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed.

scholarly journals Mechanical Properties of Steels for Cold-Formed Steel Structures at Elevated Temperatures

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Zhen Nie ◽  
Yuanqi Li ◽  
Yehua Wang
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Elevated Temperatures ◽  
Elasticity Modulus ◽  
Mechanical Performance ◽  
Strain Curve ◽  
Steel Structures ◽  
Test Method ◽  
Stress Relieving ◽  
Cold Formed Steel

It is highly important to clarify the high-temperature mechanical properties in the design of cold-formed steel (CFS) structures under fire conditions due to the unique deterioration feature in material properties under fire environment and associated reduction to the mechanical performance of members. This paper presents the mechanical properties of widely used steels for cold-formed steel structures at elevated temperatures. The coupons were extracted from original coils of proposed full annealed steels (S350 and S420, with nominal yielding strengths 280 MPa and 350 MPa) and proposed stress relieving annealed steels (G500, with nominal yielding strength 500 MPa) for CFS structures with thickness of 1.0 mm and 1.2 mm, and a total of nearly 50 tensile tests were carried out by steady-state test method for temperatures ranging from 20 to 700°C. Based on the tests, material properties including the yield strengths, ultimate strengths, the elasticity modulus, and the stress-strain curve were obtained. Meanwhile, the ductility of steels for CFS structures was discussed. Then, the temperature-dependent retention factors of yield strengths and elasticity modulus were compared to those provided by design codes and former researchers. Finally, a set of prediction equations of the mechanical properties for steels for CFS structures at elevated temperatures was proposed depending on existing tests data.

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