AS/NZS 4600 SUPP 1:1998

1 - AS/NZS 4600 Supp1:1998 COLD-FORMED STEEL STRUCTURES - COMMENTARY (SUPPLEMENT 1 TO AS/NZS 4600:1996)
4 - PREFACE
5 - CONTENTS
7 - INTRODUCTION
9 - SECTION C1 SCOPE AND GENERAL
9 - C1.1 SCOPE
9 - C1.2 REFERENCED DOCUMENTS
9 - C1.3 DEFINITIONS
10 - C1.3.13 Distortional buckling
10 - C1.3.14 Effective design width
10 - C1.3.17 Flexural-torsional buckling
10 - C1.3.19 Limit state
10 - C1.3.23 Multiple-stiffened elements
11 - C1.3.38 Stiffened or partially stiffened compression elements
13 - C1.3.46 Thickness
13 - C1.3.49 Unstiffened compression element
14 - C1.4 NOTATION
14 - C1.5 MATERIALS
14 - C1.5.1 Structural steel
21 - C1.5.2 Design stresses
23 - C1.5.3 Fasteners and electrodes
23 - C1.6 DESIGN REQUIREMENTS
23 - C1.6.1 Loads and load combinations
23 - C1.6.2 Structural analyses and design
31 - C1.7 NON-CONFORMING SHAPES AND CONSTRUCTION
32 - SECTION C2 ELEMENTS
32 - C2.1 SECTION PROPERTIES
32 - C2.1.1 General
32 - C2.1.2 Design procedures
33 - C2.1.3 Dimensional limits
35 - C2.2 EFFECTIVE WIDTHS OF STIFFENED ELEMENTS
39 - C2.2.1 Uniformly compressed stiffened elements
41 - C2.2.2 Uniformly compressed stiffened elements with circular holes
42 - C2.2.3 Stiffened elements with stress gradient
42 - C2.3 EFFECTIVE WIDTHS OF UNSTIFFENED ELEMENTS
44 - C2.3.1 Uniformly compressed unstiffened elements
44 - C2.3.2 Unstiffened elements and edge stiffeners with stress gradient
45 - C2.4 EFFECTIVE WIDTHS OF UNIFORMLY COMPRESSED ELEMENTS WITH AN EDGE STIFFENER OR ONE INTERMEDIATE STIFFENER
45 - C2.4.2 Elements with an intermediate stiffener
46 - C2.4.3 Elements with an edge stiffener
46 - C2.5 EFFECTIVE WIDTHS OF EDGE-STIFFENED ELEMENTS WITH ONE OR MORE INTERMEDIATE STIFFENERS OR STIFFENED ELEMENTS WITH MORE....
48 - C2.6 ARCHED COMPRESSION ELEMENTS
48 - C2.7 STIFFENERS
48 - C2.7.1 Transverse stiffeners
48 - C2.7.2 Shear stiffeners
48 - C2.7.3 Non-conforming stiffeners
49 - SECTION C3 MEMBERS
49 - INTRODUCTION
49 - C3.1 GENERAL
49 - C3.2 MEMBERS SUBJECT TO TENSION
49 - C3.3 MEMBERS SUBJECT TO BENDING
50 - C3.3.1 Bending moment
50 - C3.3.2 Nominal section moment capacity
53 - C3.3.3 Nominal member moment capacity
58 - C3.3.4 Shear
59 - C3.3.5 Combined bending and shear
61 - C3.3.6 Bearing
65 - C3.3.7 Combined bending and bearing
67 - C3.4 CONCENTRICALLY LOADED COMPRESSION MEMBERS
77 - C3.4.2 Sections not subject to torsional or flexural-torsional buckling
77 - C3.4.3 Doubly- or singly-symmetric sections subject to torsional or flexural-torsional buckling
77 - C3.4.4 Point-symmetric sections
77 - C3.4.5 Non-symmetric sections
78 - C3.4.6 Singly-symmetric sections subject to distortional buckling
78 - C3.4.7 Columns with one flange through-fastened to sheeting
79 - C3.5 COMBINED AXIAL LOAD AND BENDING
79 - C3.5.1 Combined axial compressive load and bending
81 - C3.5.2 Combined axial tensile load and bending
82 - C3.6 CYLINDRICAL TUBULAR MEMBERS
84 - C3.6.2 Bending
85 - C3.6.3 Compression
85 - C3.6.4 Combined bending and compression
86 - SECTION C4 STRUCTURAL ASSEMBLIES
86 - C4.1 BUILT-UP SECTIONS
86 - C4.1.1 I-sections composed of two channels
87 - C4.1.2 Cover plates, sheets or non-integral stiffeners in compression
88 - C4.2 MIXED SYSTEMS
88 - C4.3 LATERAL RESTRAINTS
88 - C4.3.2 Symmetrical beams and columns
88 - C4.3.3 Channel and Z-section beams
93 - C4.4 WALL STUDS AND WALL STUD ASSEMBLIES
94 - SECTION C5 CONNECTIONS
94 - C5.1 GENERAL
95 - C5.2 WELDED CONNECTIONS
95 - C5.2.2 Butt welds
95 - C5.2.3 Fillet welds
95 - C5.2.4 Arc spot welds (puddle welds)
97 - C5.2.5 Arc seam welds
98 - C5.2.6 Flare welds
98 - C5.2.7 Resistance welds
98 - C5.3 BOLTED CONNECTIONS
100 - C5.3.2 Tearout
101 - C5.3.3 Net section tension
101 - C5.3.4 Bearing
101 - C5.3.5 Bolts
101 - C5.4 SCREWED CONNECTIONS
101 - C5.4.1 General
102 - C5.4.2 Screwed connections in shear
104 - C5.4.3 Screwed connections in tension
105 - C5.5 BLIND RIVETED CONNECTIONS
106 - C5.6 RUPTURE
106 - C5.6.1 Shear rupture
107 - C5.6.3 Block shear rupture
108 - SECTION C6 TESTING
108 - C6.1 TESTING FOR DETERMINING MATERIAL PROPERTIES
108 - C6.1.1 Testing of unformed steel
108 - C6.1.2 Compression testing
108 - C6.1.3 Testing of full sections
108 - C6.1.4 Testing of flat coupons of formed members
108 - C6.1.5 Testing for determining section properties
108 - C6.1.6 Testing of single-point fastener connections
108 - C6.2 TESTING FOR ASSESSMENT OR VERIFICATION
108 - C6.2.1 General
109 - C6.2.2 Static tests for strength or serviceability
111 - APPENDIX A - REFERENCED DOCUMENTS

Provides background information and guidance to the requirements of AS/NZS 4600:1996.

The cross-sectional configurations, manufacturing processes and fabrication practices of cold-formed steel structural members differ in several respects from those of hot-rolled steel shapes. For cold-formed steel sections, the forming process is performed at, or near, room temperature by the use of bending brakes, press brakes or roll-forming machines. Some of the significant differences between cold-formed sections and hot-rolled shapes are-(a) absence of the residual stresses caused by uneven cooling due to hot-rolling;(b) lack of corner fillets;(c) presence of increased yield strength with decreased proportional limit and ductility resulting from cold forming;(d) presence of cold-reducing stresses when cold-rolled steel stock has not been fully annealed;(e) prevalence of elements having large width-to-thickness ratios and, hence, subject to local buckling in compression;(f) rounded corners; and(g) stress-strain curves can be either sharp-yielding type or gradual-yielding type.AS/NZS 4600 (Standards Australia/Standards New Zealand, 1996) is limited to the design of steel structural members cold-formed from carbon or low-alloy sheet, strip, plate or bar. The design is to be in accordance with the limit states design method.The Standard is applicable only to cold-formed sections not more than 25 mm in thickness. Research conducted at the University of Missouri-Rolla (Yu, Liu, and McKinney, 1973b and 1974) has verified the applicability of the Standard's provisions for such cases.In view of the fact that most of the design provisions have been developed on the experimental work subject to static loading, the Standard is intended for the design of cold-formed steel structural members to be used for load-carrying purposes in buildings. For structures other than buildings, appropriate allowances should be made for dynamic effects. The Standard does not apply to the design of structures subject to fire or fatigue since insufficient data was available on these phenomena for cold-formed members during its preparation.

First published as AS/NZS 4600 Supplement 1:1998.