Basis of design

This chapter discusses the basis of design, as covered in Section 2 of EN 1993-1-1 and Section 2 of EN 1990. The following clauses arc addressed Principles of limit state design Basic variables Verification by the partial factor method Design assisted by testing Clause 2.7 Clause 2.2 Clause 2.3 Clause 2.4 Clause 2.5 The general approach of Eurocode 3 is essentially the same as that of BS 5950, being based on limit state principles using partial safety factors. The approach is set down in detail...

General Rules And Rules For Buildings

Published by Thomas Telford Publishing. Thomas Telforcl Ltd, 1 Heron Quay. London E14 4JD URL http www.thomastclford.com Distributors for Thomas Telford books are USA ASCE Press. 1801 Alexander Bell Drive. Res ton, VA 20191-4400 Japan Maruzen Co. Ltd, Book Department, 3-10 Nihonbashi 2-chome, Chuo-ku, Tokyo 103 Australia DA Books and Journals, 64tS Whitehorse Road, Mitcham 3132, Victoria Structural Eurocodes offer the opportunity of harmonized design standards for the European construction...

Info

6640 kN > 3440 kN .-. minor axis flexural buckling resistance is acceptable Clause 6.3.2 Member buckling resistance in bending (clause 6.3.2) The 4.2 m column is unsupported along its length with no torsional or lateral restraints. Equal and opposite design end moments of 420 kN m are applied about the major axis. The full length of the column will therefore be checked for lateral torsional buckling. where fVr W L v for Class 1 and 2 cross-sections. For equal and opposite end moments (r -1),...

Ylp

Where C, may be determined from Table 6.11 for end moment loading and from Table 6.12 for transverse loading. The C, factor is used to modify Ma < (i.e. Ma C Mtr (> ) to take account of the shape of the bending moment diagram, and performs a similar function to the nt factor adopted in BS 5950. Rolled and equivalent welded case Rolled and equivalent welded case Fig. 6.22. Lateral torsional buckling curves for the general case and for rolled sections or equivalent welded sections Fig. 6.22....

L

Nominal buckling lengths Lcr for compression members lengths provided in clause 4.7.3 of BS 5950 Part 1 these buckling lengths arc not to be applied to angles, channels or T sections, for which reference should be made to clause 4.7.10 of BS 5950 Part 1. The boundary conditions and corresponding buckling lengths arc illustrated in Fig. 6.19, where L is equal to the system length. Example 6.7 buckling resistance of a compression member A circular hollow section (CHS) member is to be...

M

Is the horizontal reaction at the bottom of the storey due to the horizontal loads (e.g. wind) and the fictitious horizontal loads is the total design vertical load on the structure at the level of the bottom of the storey under consideration is the horizontal deflection at the top of the storey under consideration relative to the bottom of the storey, with all horizontal loads (including the fictitious loads) applied to the structure is the storey height. Resistance to sway deformations can be...

Preface

With the UK poised to adopt the set of structural Eurocodes it is timely to produce a series of guides based on their technical content. For the design of steel structures, Eurocode 3 Design of Steel Structures, Part 1.1 General Rules and Rules for Buildings (EN 1993-1-1) is the master document. It is, however, complemented by several other parts, each of which deals with a particular aspect of the design of structural steelwork. This text concentrates on the main provisions of Part 1.1 of the...

Structural analysis

This chapter concerns the subject of structural analysis and classification of cross-sections for steel structures. The material in this chapter is covered in Section 5 of EN 1993-1-1, and the following clauses are addressed Before the strength of cross-sections and the stability of members can be checked against the requirements of the code, the internal (member) forces and moments within the structure need to be determined from a global analysis. Four distinct types of global analysis are...

Ultimate limit states

This chapter concerns the subject of cross-section and member design at ultimate limit states. The material in this chapter is covered in Section 6 of EN 1993-1-1 and the following clauses are addressed Resistance of cross-sections Buckling resistance of members Uniform built-up compression members Clause 6.1 Clause 6.2 Clause 6.3 Clause 6.4 Unlike BS 5950 Part I, which is largely self-contained, EN 1993-1-1 is not a stand-alone document. This is exemplified in Section 6, where reference is...

University Of Sheffield

Example 6.3 demonstrates calculation of the bending resistance of a cross-section with a Class 1 flange and a Class 3 web. Also, comparison is made between the bending resistance using elastic section properties (i.e. assuming a Class 3 cross-section) and using the effective plastic properties described above. The resistance of tension members is covered in clause 6.2.3. The design tensile force is denoted by A'Ed (axial design effect). In Eurocode 3, similarly to BS 5950 Part 1 design tensile...

1

V x Rd may be obtained from clause 6.2.6. and when torsion is present Kpl Rd should be replaced by Vpl T Rd, obtained from clause 6.2.7. An alternative to the reduced design strength for the shear area, defined by equation (6.29). which involves somewhat tedious calculations, is equation (6.30). Equation (6.30) may be applied to the common situation of an I scction (with equal flanges) subjected to bending about the major axis. In this case the reduced design plastic resistance moment allowing...

W

1.01x1.00 x---x-x 0.6 x A 0.69 Check compliance with interaction formulae (equations (6.61) and (6.62)) + +*r < 1 (6.67) 0.94 < 1.0 equation (6.61) is satisfied > - -+ 0.69x-- 0.04 + 0.57 0.61 (0.77 x 2947) 1.0 (0.97 x 174.3) 1.0 0.61 < 1.0 equation (6.62) is satisfied Therefore, a hot-rolled 200 x 100 x 16 RHS in grade S355 steel is suitable for this application. For comparison, from the Annex B method, . 1.06 k.y 1.00 which gives, for equation (6.61), 0.07 + 0.87 0.94 (0.94 < 1.0...

J V

. limit for a Class 2 web 7 52.33 Overall cross-section classification under the combined loading is therefore Class 2. Conclusion For this cross-section, a maximum axial force of 411 kN may be sustained in combination with a major axis bending moment, whilst remaining within the limits of a Class 2 section. Cross-section and member resistance to combined bending and axial force is covered in Sections 6.2.9 and 6.3.3 of this guide, respectively. 5.6. Cross-section requirements for plastic...

Second Order Analysis Eurocode

Typical beam-to-column joints, a Simple joint b Semi-continuous joint, c Rigid joint Clause 5.2 Clause 5.2 explains how a second-order analysis i.e. one in which the effect of deformations significantly altering the member forces or moments or the structural behaviour is explicitly ClauseS.3 allowed for should be conducted. Clause 5.3 deals with the inclusion of geometrical Clause 5.4 imperfections both for the overall structure and for individual members, whilst clause 5.4 covers the...

General Ru Les And Rules For Buildings

Eurocode Basis of Structural Design. H. Gulvanessian, J.-A. Calgaro and M. Holicky. 0 7277 301 I 8. Published 2002. Designers' Guide to EN 1994-1-1. Eurocode 4 Design of Composite Steel and Concrete Structures. Part I.I General Rules and Rules for Buildings. R. P. Johnson and D. Anderson. 0 7277 3151 3. Published 2004. Des gners' Guide to EN 1997-1. Eurocode 7 Geotechnical Design - General Rules. R. Frank, C. Bauduin, R. Driscoll, M. Kawadas, N. Krebs Ovesen, T. Orr...

Lj

Selection of buckling curve and imperfection factor a For a hot-rolled CHS, use buckling curve a Table 6.5 Table 6.2 of EN 1993-1-1 . For curve buckling curve a, a 0.21 Table 6.4 Table 6.1 of EN 1993-1-1 . lt P 0.5 1 0.21 x 0.56 - 0.2 0.562 0.69 1 0.91x7370x275 _ . KT Rd - - 1836.3 x 10 N 1836.D kN 1836.5 gt 1630 kN buckling resistance is acceptable The chosen cross-section, 244.5 x 10 CHS, in grade S275 steel is acceptable. Laterally unrestrained beams subjected to bending about their major...

B A

Staggered arrangement of fastener holes Fig, 6.3. Angle with holes in both legs The method for calculating the net area of a cross-section in EN 1993-1-1 is essentially the same as that described in BS 5950 Part 1, with marginally different rules for sections such as angles with fastener holes in both legs. In general, the net area of the cross-section is taken as the gross area less appropriate deductions for fastener holes and other openings. For a non-staggered arrangement of...

Ei I

Ich is the in-plane second moment of area of one chord about its own neutral axis h is the in-plane second moment of area of one batten about its own neutral axis . The effective second moment of area L.ff of a battened built-up member is given in clause Clause 6.4.3.1 3 6.4.3.1 3 , and may be taken as where .i is a so-called efficiency factor, taken from Table 6.8 of EN 1993-1-1. The second part of the right-hand side of equation 6.74 , 2 i ch, represents the contribution of the moments of...

Bending Members Eurocode

Class 3 - local buckling prevents attainment of full plastic moment Class 4 - local buckling prevents attainment of yield moment Fig. 5.6. The four behavioural classes of cross-section defined by Eurocode 3 bending. Class 3 cross-scctions are fully effective in pure compression, but local buckling prevents attainment of the full plastic moment in bending bending moment resistance is therefore limited to the elastic yield moment. For Class 4 cross-sections, local buckling occurs in the elastic...

General

This chapter discusses the general aspects of EN 1993-1-1, as covered in Section J of the code. The following clauses arc addressed Normative references Clause 1.2 Distinction between Principles and Application Rules Clause 1.4 Terms and definitions Clause 1.5 Conventions for member axes Clause 1.7 Finalization of the Eurocodes, the so-called conversion of ENVs into ENs, has seen each of the final documents subdivided into a number of parts, some of which have then been further subdivided....

Steel Section Table

Steel Section Table

Selection of buckling curve for a cross-section Table 6.2 of EN 1993-1-I Table 6.5. Selection of buckling curve for a cross-section Table 6.2 of EN 1993-1-I The choice as lo which buckling curve imperfection factor to adopt is dependent upon the geometry and material properties of the cross-section and upon the axis of buckling. The appropriate buckling curvc should be determined from Table 6.5 Table 6.2 of EN 1993-1-1 , which is equivalent to the 'allocation of strut curve' tabic...

Ol

Calculation of the non-dimensional slenderness A,, for torsional and torsional-flexural buckling is covered in clause 6.3.1.4, and should be taken as Clause 6.3.1.4 for Class 1, 2 and 3 cross-sections 6.52 for Class 4 cross-sections 6.53 Ncr rF is the elastic critical torsional-flexural buckling force see Section 13.7 of this guide A'cr T is the elastic critical torsional buckling force see Section 13.7 of this guide . The generic definition of Ar is the same as the definition of Ax for...

Mo

Tension Structures

Where the subscript 'min' indicates that the minimum value of Wel or Wcff should be used i.e. the elastic or effective modulus should be based on the extreme fibre that reaches yield first. Example 6.3 cross-section resistance in bending A welded I section is to be designed in bending. The proportions of the section have been selected such that it maybe classified as an effective Class 2 cross-section, as described in Section 6.2.2 of this guide. The chosen section is of grade S275 steel, and...

Durability

This short chapter conccrns the subject of durability and covers the material set out in Section 4 of EN 1993-1-1, with brief reference to EN 1990. Durability may be defined as the ability of a structure to remain fit for its intended or foreseen use throughout its design working life, with an appropriate level of maintenance. For basic durability requirements, Eurocode 3 directs the designer to Section 2.4 of EN 1990, where it is stated that 'the structure shall be designed such that...

Introduction To Eurocode

The material in this introduction relates to the foreword to the European standard EN 1993-1-1, Eurocode 3 Design of Steel Structures, Part 1.1 General Rules and Rules for Buildings. The following aspects are covered Background to the Eurocode programme Status and field of application of Eurocodes National standards implementing Eurocodes Links between Eurocodes and product-harmonized technical specifications ENs and ETAs Additional information specific to EN 1993-1 National Annex for EN...