Second Order Analysis Eurocode
Fig. 5.2. 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...
V
And for outstand compression elements A -0.188 bufil0 D63 is the ratio of end stresses acting on the compression element in accordance with clauses 4.4 3 and 4.4 4 of EnI993-1-5 . is the appropriate width as follows b for webs, taken as the clear width between welds or fillets b for internal flange elements, taken as c from Table 5.2 sheet 1 b - 3 for flanges of rectangular hollow section c for outstand Ranges, taken as the clear width from the weld or fillet to the flange tip h for equal and...
X
beff pbc pb i-tiO be. 0,4beff be2 0,6beif
General Ru Les And Rules For Buildings
Designers' Guide to EN 1990. 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...
L Hpo
Fig. 7.2. Definitions of horizontal deflections Table 7.3. Horizontal deflection limits Tops of columns in single storey buildings, except portal frames Columns in portal frame buildings, not supporting crane runways In each storey of a building with more than one storey Height 300 To suit cladding Height of storey 300 Horizontal dcllcctions in structures may be chcckcd using the same combinations of actions as for vertical deflections. The EN 1990 notation to describe horizontal deflections is...
K Nmh
where r, Ed and rw Ed arc defined above and KpJ Kd is obtained from clause 6.2.6. 6.2.8. Bending and shear Bending moments and shear forces acting in combination on structural members is commonplace. However, in the majority of cases and particularly when standard rolled sections are adopted the effect of shear force on the moment resistance is negligible and may be ignored - clause 6.2.8 2 states that provided the applied shear force is less than half the plastic shear resistance of the...
Al
is the elastic critical buckling force for the relevant buckling mode based on the gross properties of the cross-section. The non-dimensional slenderness A, as defined above, is in a generalized format requiring the calculation of the elastic critical force N for the relevant buckling mode. The relevant buckling mode that governs design will be that with the lowest critical buckling force Na. Calculation of N , and hence A, for the various buckling modes is described in the following section....
Wa
is an imperfection factor from Table 6.7 Table 6.3 of EN 1993-1-1 is the elastic critical moment for lateral torsional buckling see the following The imperfection factors n,, for the four lateral torsional buckling curves are given by Tabic 6.7 Table 6.3 of EN 1993-1-1 . Selection of the appropriate lateral torsional buckling curve for a given cross-section type and dimensions may be made with reference to Table 6.8 Table 6.4 of EN 1993-1-1 . It should be noted that the UK National Annex may...
Info Tdo
Fig. 6.23. Tabulated and approximate values of C, for varying tj gt The values of C, given in TabLe 6.11 for end moment loading may be approximated by equation D6.10 , though other approximations also exist 1' where il gt is the ratio of the end moments defined in Table 6.10 . Figure 6.23 compares values of C, obtained from Table 6.11 and from equation D6.ll . Figure 6.23 shows, as expected, that the most severe loading condition that of uniform bending moment where 1-0 results in the lowest...
L
Fig. 5.5. Replacement of initial imperfections by quivalent horizontal forces 5.4. Methods of analysis considering material non-linearities This section sets out in rather more detail than is customary in codes the basis on which the pattern of the internal forces and moments in a structure necessary for the checking of Clause 5.4.2 individual member resistances should be calculated. Thus, clause 5.4.2 permits the use of linear elastic analysis, including use in combination with member checks...
Ajj
Aci is the effective area of the cross-section under pure compression IV,Jf min is the effective section modulus about the relevant axis, based on the extreme fibre that reaches yield first is the shift in the relevant neutral axis. 6.2.10. Bending, shear and axial force The design of cross-sections subjected to combined bending, shear and axial force is covered Clause 6.2.10 in clause 6.2.10. However, provided the shear force VM is less than 50 of the design plastic Clause 6.2.6 shear...
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...
Materials
This chapter is concerned with the guidance given in EN 1993-J -1 for materials, as covered in Section 3 of the code. The following clauses arc addressed General Structural steel Connecting deviccs Other prefabricated products in buildings Clause 3.1 Clause 3.2 Clause 3.3 Clause 3 A In general, the nominal values of material properties provided in Section 3 of EN 1993-1-1 may be used in the design expressions given throughout the code. However, the UK National Annex may specify exceptions to...
Info Uqu
Table 6.3. Determination of k.t for outstand compression elements Table 4.2 of EN 1993-1 -S Table 6.3. Determination of k.t for outstand compression elements Table 4.2 of EN 1993-1 -S Stress distribution compression positive
Info Plm
Table 7.2. Vertical deflection limits Table 7.2. Vertical deflection limits Beams carrying plaster or other brittle finish Other beams except purlins and sheeting rails The UK National Annex may define similar limits to those given in Table 7.2, and is likely to propose that permanent actions be taken as zero in serviceability checks, essentially reverting to the practice in BS 5950, which is to check deflections under unfactored imposed loading. In this case w and w2 would be zero, so w OI...
M Ibi
Determination of interaction factors k Annex B For this example, alternative method 2 Annex B will be used for the determination of the interaction factors kir For axial compression and bi-axial bending, all four interaction coefficients kn kv , k and k z arc required. The column is laterally and torsionally unrestrained, and is therefore susceptible to torsional deformations. Accordingly, the interaction factors should be determined with initial reference to Table B.2. Equivalent uniform...
Info Sex
Overall cross-section classification Oncc the classification of the individual parts of the cross-section is determined. Eurocode 3 allows the overall cross-section classification to be defined in one of two ways 1 The overall classification is taken as the highest least favourable class of its component parts, with the exceptions that i cross-sections with Class 3 webs and Class 1 or 2 Clause 6.2.2.4 flanges may be classified as Class 2 cross-sections with an effective web defined in clause...
E
coefficient of thermal expansion a 12 x 106 C Those familiar with design to British Standards will notice a marginal approximately 2 difference in the value of Young's modulus adopted in EN 1993-1-1, which is 210 000 N mra2, compared with 205 000 N mnr. Requirements for fasteners, including bolts, rivets and pins, and for welds and welding consumables are given in Eurocode 3 - Part 1.8, and are discussed in Chapter 12 of this guide. 3.4. Other prefabricated products in buildings Clause 3.4 1 B...
B A
Fig. 6.2. 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...
Info Xis
386.8 kN m gt 367.5 kN m . . cross-section resistance to combined bending A 406 x 178 x 74 UB in grade S275 steel is suitable for the arrangement and loading shown by Fig. 6.13. The design of cross-sections subjected to combined bending and axial force is described in clause 6.2.9. Bending may be about one or both principal axes, and the axial force may be tensile or compressive with no difference in treatment . In dealing with the combined effects, Eurocode 3 prescribes different methods for...
Bending Members Eurocode 3
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....
Info Obl
0.79x8415 1.0 ky2 0.6 kzl 0.6 x 0.72 0.47 0.1x0.59 3440 0.40-0.25 0.79x8415 1.0 0.40 - 0.25 0.79 x 8415 1.0 9 Check compliance with interaction formulae equations 6.61 and 6.62 XyN y.Wnhm M z. Rk' Ml 3440 - 0.41 x . 42 - _ 0.47 x 0.41 0.15 0.10 gt 0.99x8415 0.66 lt 1.0 equation 6.61 is satisfied K-, -cu, A',. w lt 1 6.62 3440 - 0.79X- _ 0.78x- M_ ,52 0.29 0.16 gt 0,79x8415 4.0 ' 0.99x1168 1.0 536.5 1.0 0.97 lt 1.0 equation 6.62 is satisfied Therefore, a hot-rolled 305 x 305 x 240 H section in...
M Izi
where ArRd, Mv Rd and M. Rd are the design cross-sectional resistances and should include any necessary reduction due to shear effects clause 6.2.8 . The intention of equation 6.2 is simply to allow a designer to generate a quick, approximate and safe solution, perhaps for the purposes of initial member sizing, with the opportunity to refine the calculations for final design. Class I and 2 cross-sections mono-axial bending and axial force The design of Class 1 and 2 cross-sections subjected to...
Steel Section Table
Table 6.5. 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...
M Apq
A'td, My ,.d, M. ,,d are the design values of the compression force and the maximum moments about the gt '- gt ' and z-z axes along the member, respectively jVRk, M Rk, M. Rk are the characteristic values of the compression resistance of the cross-section and the bending moment resistances of the cross-section about the y-y and z-z axes, respectively are the reduction factors due to flexural buckling from clause 6.3.1 is the reduction factor due to lateral torsional buckling from clause 6.3.2....
Mo 1
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 3
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...
Warping Torsional Resistance Moment
228.6 mm 6 88.9 mm t,. 8.6 mm lt 13.3 mm r 13.7 mm .4 4160 mm2 Fig. 6.12. Section properties for a 229 x 89 mm rolled channel section 235 . 7235 275 0.92 r 1.2 from EN 1993-1-5, though the UK National Annex may specify an alternative value . Actual hjtw h - 2 , 228.6 - 2 x13.3 8.6 23.5 23.5 lt 55.5 . . no shear buckling check required The shear resistance of a 229 x 89 rolled channel section in grade S275 steel loaded parallel to the web is 332 kN. For the same cross-section. BS 5950 2000...
Info Osc
All steel grades listed in Table 3.1 meet these criteria, so do not have to be explicitly checked. However, the UK National Annex may set slightly more strict requirements, in which case the grades given in Table 3.1 should be checked. In any case, it is only the higher-strength grades that may fail to meet the ductility requirements. In order to avoid brittle fracture, materials need sufficient fracture toughness at the lowest service temperature expected to occur within the intended design...
Chapter I General
A useful listing of the majority of symbols used in EN 1993-1-1 is provided in clause L6. Clause 1.6 Other symbols are defined where they are first introduced in the code. Many of these symbols, especially those with multiple subscripts, will not be familiar to UK designers. However, there is generally good consistency in the use of symbols throughout the Eurocodes, which makes transition between the documents more straightforward. The convention for member axes in Eurocode 3 is not the same as...
M Ojg
For Class 1,2 and 3 cross-sections, the design compression resistance is taken as the gross cross-sectional area multiplied by the nominal material yield strength and divided by the partial factor 7M0, and likewise for Class 4 cross-sections with the exception that effective section properties a_re used in place of the gross properties. In calculating cross-sectional areas for compression resistance, no allowance need be made for fastener holes where fasteners are present except for oversize or...