EN 1993-1-1 DK NA:2015

Foreword DS/EN 1993-1-1 DK NA:2015 ... The list below identifies the clauses where national choices are possible and the applicable/not ap- ... 7.2.1(...

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DS/EN 1993-1-1 DK NA:2015 National Annex to Eurocode 3: Design of steel structures – Part 1-1: General rules and rules for buildings _______________________________________________________________________

Foreword This national annex (NA) is a revision of DS/EN 1993-1-1 DK NA:2014 and replaces the latter on 2015-01-01. In addition to minor editorial changes, the publication of DS/EN 1993-1-1/A1:2014 has resulted in the addition of national choices in C.2.2(3) and C.2.2(4); the complementary information regarding 2.1.2 has consequently been deleted. Previous versions of and addenda to this NA as well as an overview of all NAs can be found at www.eurocodes.dk This NA lays down the conditions for the implementation in Denmark of EN 1993-1-1 for construction works in conformity with the Danish Building Act or the building legislation. Other parties can put this NA into effect by referring thereto. A National Annex contains national provisions, viz. nationally applicable values or selected methods. The Annex may furthermore give complementary, non-contradictory information. This NA includes:   

an overview of possible national choices and clauses containing complementary information; national choices; complementary, non-contradictory information.

Page 1 of 8 Foreword

DS/EN 1993-1-1 DK NA:2015

Overview of possible national choices and complementary information The list below identifies the clauses where national choices are possible and the applicable/not applicable informative annexes. Furthermore, clauses giving complementary information are identified. Complementary information is given at the end of this National Annex. Clause

National choice 1)

Subject

Complementary information

2.3.1(1)

Actions and environmental influences

Unchanged

3.1(2)

Materials, General

National choice

3.2.1(1)

Material properties

National choice

3.2.2(1)

Ductility requirements

Unchanged

3.2.3(1)

Fracture toughness"

Unchanged

3.2.3(3)B

Fracture toughness"

Unchanged

3.2.4(1)B

Through-thickness properties

Unchanged

5.2.1(3)

Effects of deformed geometry of the structure

National choice

5.2.2(8)

Structural stability of frames

5.3.2(3)

Imperfections for global analysis of frames

Unchanged

5.3.2(11)

Imperfections for global analysis of frames

National choice

5.3.4(3)

Member imperfections

Unchanged

Complementary information Complementary information

6.1(1)

National choice

6.1(1)2B

Ultimate limit states, General

National choice

6.2.2

Resistance of cross-sections - Section properties

6.3.2.2(2)

Lateral torsional buckling curves – General Unchanged case

6.3.2.3(1)

Lateral torsional buckling curves for rolled Unchanged sections or equivalent welded sections

6.3.2.3(2)

Lateral torsional buckling curves for rolled National choice sections or equivalent welded sections

6.3.2.4(1)B

Simplified assessment methods for beams with Unchanged restraints in buildings

6.3.2.4(2)B

Simplified assessment methods for beams with Unchanged restraints in buildings

6.3.3(5)

Interactive factors for members in bending and National choice axial compression

Complementary information

Complementary information

Complementary information

Page 2 of 8 Overview, national choices and complementary information

DS/EN 1993-1-1 DK NA:2015

Clause

National choice 1)

Subject

Complementary information

6.3.4(1)

General method for lateral and lateral torsional National choice buckling of structural components

7.2.1(1)B

Vertical deflections

National choice

7.2.2(1)B

Horizontal deflections

National choice

7.2.3(1)B

Dynamic effects

Unchanged

Annex A

Applicable

Annex B

Applicable

Annex AB

Applicable

Annex BB

Applicable

Complementary information

BB.1.3(3)B

Hollow sections as members

National choice

C.2.2(3)

Selection of execution class - general

National choice

C.2.2(4)

Selection of execution class - components

National choice

1)

Unchanged: The recommendation in the Eurocode is followed. No choice made: The Eurocode does not recommend values or methods, but allows the option of determining national values or methods. Not applicable The Annex is not applicable. Applicable The Annex is applicable in Denmark and has the same status as specified in the Eurocode. National choice: A national choice has been made. Not relevant for building structures: See the National Annexes published by the Danish Road Directorate and Banedanmark.

Page 3 of 8 Overview, national choices and complementary information

DS/EN 1993-1-1 DK NA:2015

National choices 3.1(2) Materials, General The standard applies to steel materials in accordance with Table 3.1 of DS/EN 1993-1-1 or equivalent. 3.2.1(1) Material properties The values of fy and fu specified in (1) a) should be used. 5.2.1(3) Effects of deformed geometry of the structure A lower value of αcr than that that given in (5.1) may be used if justification of its application is documented. 5.3.2(11) Imperfections for global analysis of frames Which of the methods referred to in (3), (6) and (11) to be used should be determined for each individual case. 6.1(1) Ultimate limit states, General The below expressions for Mi are used, including the factor (γ0) on the partial factors for strength parameters and resistances, cf. National Annex to EN 1990, Table A1.2(B+C) DK NA: M0 = 1,1 · 0 · 3 M1 = 1,2 · 0 · 3 M2 = 1,35 · 0 · 3 The factor 0 takes into account the combination of actions, cf. National Annex to EN 1990, Table A1.2(B+C) DK NA. Limit state

STR/GEO

Combination of actions 0

STR

1

2

3

4

5

1,0

1,0

KFI

KFI

1,2·KFI

The factor 3 takes into account the level of checking of the product. The reduced level of checking is not used. Extended level of checking: 3 = 0,95 Normal level of checking: 3 = 1,00 The partial factors are determined in accordance with the National Annex to EN 1990, Annex F, Partial factors for resistance, where γM = γ1 γ2 γ3 γ4, where the values of γMi given above include the factor 0.

Page 4 of 8 National choices

DS/EN 1993-1-1 DK NA:2015

γ1 γ2 model; γ3 γ4

takes into account the type of failure; takes into account the uncertainty related to the design takes into account the extent of checking; takes into account the variation of the strength parameter or resistance.

When determining γ1, the following types of failure have been assumed: M0: M1: M2:

Warning of failure with residual resistance Warning of failure without residual resistance No warning of failure

For accidental and seismic design situations the following values are used: M0 = 1,0 M1 = 1,0 M2 = 1,0 6.1(1)NOTE 2B Ultimate limit states, General See 6.1(1) 6.3.2.3(2) Lateral torsional buckling curves for rolled sections or equivalent welded sections f = 1. The determination of Mcr takes into account the moment distribution between lateral restraints. See also the complementary information. 6.3.3(5) Uniform members in bending and axial compression Both Method 1 and Method 2 may be used to determine the values of the interaction factors kyy, kyz, kzy and kzz . See also the complementary information. 6.3.4(1) General method for lateral and lateral torsional buckling of structural components The relevance of using the method in 6.3.4 is to be evaluated for each case. 7.2.1(1)B Vertical deflections For beams, the following values of the maximum deflection (w3 in EN 1990, Figure A1.1) due to one variable action without allowance for impact, if any, may serve as guidance as to what may be regarded as acceptable deflections:  floors l/400  roofs and external walls l/200 Where l is:  the span of simply supported and continuous beams;  twice the projection of cantilevered structures. The values apply both to main and secondary elements, but only the deflection of the element considered is to be used in the assessment.

Page 5 of 8 National choices

DS/EN 1993-1-1 DK NA:2015

For secondary sheeting in the form of uninsulated roof sheeting and for facade sheeting, the deflection due to permanent and variable actions should not exceed l/90. For roof sheeting with external insulation and roofing felt, the deflection due to permanent and variable actions should not exceed: l/150 for l < 4 500 mm 30 mm for 4 500 mm ≤ l < 6 000 mm l/200 for 6 000 mm ≤ l

7.2.2(1)B Horizontal deflections For columns, the following numerical values of the maximum deflection of the column head due to one variable action may serve as guidance to what may be regarded as acceptable deflections:  frames in buildings without cranes  columns in single-storey skeleton structures  columns in multi-storey skeleton structures, for each storey for the total height

h/150 h/300 h/300 he /500

Where  h is the height of the individual column  he is the total height of the building.

BB.1.3(3)B Hollow sections as members Further information on buckling lengths of compression members should be found in textbooks.

C.2.2(3) Selection of execution class The execution class is selected on the basis of the consequences class.

Table C.1 DK NA ― Selection of execution class (EXC) Consequences class Type of action Static, quasi-static or seismic Fatigue b) or seismic DCL a) DCM or DCH a) c) CC3 EXC3 EXC3 c) CC2 EXC2 EXC3 d) CC1 EXC1/EXC2 EXC2 a) Seismic ductility classes are defined in DS/EN 1998-1: Low = DCL, medium = DCM, high = DCH. b) See DS/EN 1993-1-9. c) EXC4 should be used for structural components where the consequences of failure are particularly serious. d) EXC2 for welds. See C.2.2(4). Page 6 of 8 National choices

DS/EN 1993-1-1 DK NA:2015

C.2.2(4) Selection of execution class For the execution of welds, DS/EN 1993-1-8 specifies that a weld of at least quality level C (according to DS/EN ISO 5817) is normally required unless otherwise specified. Therefore, at least execution class EXC2 should be applied for the welded connections in the structure. For structures of consequences class CC1, EXC1 may be used for the fillet weld if the throat thickness of the fillet weld is increased by 20 %, and quality level C is applied with the exception that quality level D can be applied for "Undercut" (5011, 5012), "Overlap" (506), "Stray arc" (601) and "End crater pipe" (2025).

Page 7 of 8 National choices

DS/EN 1993-1-1 DK NA:2015

Complementary, non-contradictory information 3.2.4(1) Through-thickness properties It is recommended that structural components subject to stress in the through-thickness direction should be protected against lamination according to DS/EN 10160, class S1. 5.2.2(8) Structural stability of frames Detailed guidelines are not given for structural analyses of the stability of frames using a method based on equivalent buckling lengths. Guidance should be found in specialist literature or the method of analysis should be documented by other means. 6.2.2 Resistance of cross-sections - Section properties For a long-threaded structural component, the gross cross section and the net cross section are taken as the stress area as defined in DS/EN 1993-1-8, 1.5. The connection at the end of the component should also conform to the design rules for bolted connections specified in DS/EN 1993-1-8. 6.3.2.3(2) Lateral torsional buckling curves – General case Justification for changing 6.3.2.3(2) Lateral torsional buckling curves for rolled sections or equivalent welded sections The specified method assumes (cf. ECCS Publication 119) that when calculating Mcr and consequently λLT, a uniform moment distribution between the lateral restraints is taken into account corresponding to Ψ = 1 in Table 6.6, and not the real moment distribution as in 6.3.2.2. The real moment distribution has been taken into account by the factor f. The text of the change specifies that also when using this method, Mcr is to be determined on the basis of the real moment distribution between the lateral restraints, and f is taken as 1. 6.3.3(5) Uniform members in bending and axial compression Method 1 is recommended for significant structures and where cost is decisive, and as a basis for the preparation for design programs. Method 2 is recommended as a simpler method for less significant structures. See also the national choice. Annex B, Method 2 – Interaction factors kij for interaction formula in 6.3.3(4) Table B.3: Equivalent uniform moment factors Cm in Tables B.1 and B.2 Ms is to be obtained according to the value of bending moment diagram which yields a local extreme (dMs/dx = 0) between end points of beam elements (x = 0 and x = L). Where a local extreme does not exist, Ms is to be taken as the value obtained at the centre of the beam element.

Page 8 of 8 Complementary information

DS/EN 1993-1-1 DK NA:2015