Eurocode 3 - Design of joints

FINAL DRAFT

EUROPEAN STANDARD prEN 1993-1-8

NORME EUROPÉENNE

EUROPÄISCHE NORM December 2003

ICS Will supersede ENV 1993-1-1:1992

English version

Eurocode 3: Design of steel structures - Part 1-8: Design of

joints

Eurocode 3: Calcul des structures en acier - Partie 1-8: Eurocode 3: Bemessung und Konstruktion von Stahlbauten

Calcul des assemblages - Teil 1-8: Bemessung von Anschlüssen

This draft European Standard is submitted to CEN members for formal vote. It has been drawn up by the Technical Committee CEN/TC

250.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which

stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has

the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,

Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United

Kingdom. : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and

Warning

shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION

COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2003 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1993-1-8:2003 E

worldwide for CEN national Members.

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1.1 Scope 6

1.2 Distinction between Principles and Application Rules 6

1.3 Definitions 6

1.4 Symbols 7

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2.1 Assumptions 13

2.2 General requirements 13

2.3 Applied forces and moments 13

2.4 Resistance of joints 13

2.5 Design assumptions 14

2.6 Joints loaded in shear subject to impact, vibration and/or load reversal 14

2.7 Eccentricity at intersections 14

2.8 References 15

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3.1 Bolts, nuts and washers 18

3.1.1 General 18

3.1.2 Preloaded bolts 18

3.2 Rivets 18

3.3 Anchor bolts 18

3.4 Categories of bolted connections 18

3.4.1 Shear connections 18

3.4.2 Tension connections 19

3.5 Positioning of holes for bolts and rivets 20

3.6 Design resistance of individual fasteners 21

3.6.1 Bolts and rivets 21

3.6.2 Injection bolts 25

3.7 Group of fasteners 26

3.8 Long joints 26

3.9 Slip-resistant connections using 8.8 or 10.9 bolts 27

3.9.1 Design Slip resistance 27

3.9.2 Combined tension and shear 28

3.9.3 Hybrid connections 28

3.10 Deductions for fastener holes 28

3.10.1 General 28

3.10.2 Design for block tearing 29

3.10.3 Angles connected by one leg and other unsymmetrically connected members in tension 30

3.10.4 Lug angles 31

3.11 Prying forces 31

3.12 Distribution of forces between fasteners at the ultimate limit state 31

3.13 Connections made with pins 32

3.13.1 General 32

3.13.2 Design of pins 32

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4.1 General 35

4.2 Welding consumables 35

4.3 Geometry and dimensions 35

4.3.1 Type of weld 35

4.3.2 Fillet welds 35

4.3.3 Fillet welds all round 36

4.3.4 Butt welds 36

4.3.5 Plug welds 37

4.3.6 Flare groove welds 38

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4.4 Welds with packings 38

4.5 Design resistance of a fillet weld 38

4.5.1 Length of welds 38

4.5.2 Effective throat thickness 38

4.5.3 Design Resistance of fillet welds 39

4.6 Design resistance of fillet welds all round 41

4.7 Design resistance of butt welds 41

4.7.1 Full penetration butt welds 41

4.7.2 Partial penetration butt welds 41

4.7.3 T-butt joints 41

4.8 Design resistance of plug welds 42

4.9 Distribution of forces 42

4.10 Connections to unstiffened flanges 43

4.11 Long joints 44

4.12 Eccentrically loaded single fillet or single-sided partial penetration butt welds 44

4.13 Angles connected by one leg 45

4.14 Welding in cold-formed zones 45

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5.1 Global analysis 47

5.1.1 General 47

5.1.2 Elastic global analysis 47

5.1.3 Rigid-plastic global analysis 48

5.1.4 Elastic- plastic global analysis 48

5.1.5 Global analysis of lattice girders 49

5.2 Classification of joints 51

5.2.1 General 51

5.2.2 Classification by stiffness 51

5.2.3 Classification by strength 52

5.3 Modelling of beam-to-column joints 53

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6.1 General 57

6.1.1 Basis 57

6.1.2 Structural properties 57

6.1.3 Basic components of a joint 58

6.2 Design Resistance 62

6.2.1 Internal forces 62

6.2.2 Shear forces 62

6.2.3 Bending moments 63

6.2.4 Equivalent T-stub in tension 64

6.2.5 Equivalent T-stub in compression 67

6.2.6 Design Resistance of basic components 68

6.2.7 Design Moment resistance of beam-to-column joints and splices 81

6.2.8 Design Resistance of column bases with base plates 86

6.3 Rotational stiffness 89

6.3.1 Basic model 89

6.3.2 Stiffness coefficients for basic joint components 91

6.3.3 End-plate connections with two or more bolt-rows in tension 94

6.3.4 Column bases 95

6.4 Rotation capacity 96

6.4.1 General 96

6.4.2 Bolted joints 97

6.4.3 Welded Joints 97

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7.1 General 98

7.1.1 Scope 98

7.1.2 Field of application 98

7.2 Design 100

7.2.1 General 100

7.2.2 Failure modes for hollow section connections 100

7.3 Welds 104

7.3.1 Design resistance 104

7.4 Welded joints between CHS members 105

7.4.1 General 105

7.4.2 Uniplanar joints 105

7.4.3 Multiplanar joints 112

7.5 Welded joints between CHS or RHS brace members and RHS chord members 113

7.5.1 General 113

7.5.2 Uniplanar joints 114

7.5.3 Multiplanar joints 125

7.6 Welded joints between CHS or RHS brace members and I or H section chords 126

7.7 Welded joints between CHS or RHS brace members and channel section chord members 129

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This document (prEN 1993-1-8: 2003) has been prepared by Technical Committee CEN/TC 250 "Structural

Eurocodes", the secretariat of which is held be BSI.

This document is currently submitted to the Formal Vote.

This document will supersede ENV 1993-1-1.

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This standard gives alternative procedures, values and recommendations with notes indicating where national

choices may have to be made. The National Standard implementing EN 1993-1-8 should have a National

Annex containing all Nationally Determined Parameters for the design of steel structures to be constructed in

the relevant country.

National choice is allowed in EN 1993-1-8 through:

2.2(2)

– 2.8 (Group 6: Rivets)

– 3.4.2(3)

– 6.2.7.2(9)

–

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(1) This part of EN 1993 gives design methods for the design of joints subject to predominantly static

loading using steel grades S235, S275, S355 and S460.

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(1) The rules in EN 1990 clause 1.4 apply.

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(1) The following terms and definitions apply:

EDVLFFRPSRQHQW(of a joint): Part of a joint that makes a contribution to one or more of its structural

– properties.

FRQQHFWLRQ: Location at which two or more elements meet. For design purposes it is the assembly of

– the basic components required to represent the behaviour during the transfer of the relevant internal

forces and moments at the connection.

FRQQHFWHGPHPEHU: Any member that is joined to a supporting member or element.

– MRLQW: Zone where two or more members are interconnected. For design purposes it is the assembly of

– all the basic components required to represent the behaviour during the transfer of the relevant internal

forces and moments between the connected members. A beam-to-column joint consists of a web panel

and either one connection (single sided joint configuration) or two connections (double sided joint

configuration), see Figure 1.1.

MRLQWFRQILJXUDWLRQ: Type or layout of the joint or joints in a zone within which the axes of two or

– more inter-connected members intersect, see Figure 1.2.

URWDWLRQDOFDSDFLW\: The angle through which the joint can rotate without failing.

– URWDWLRQDOVWLIIQHVV: The moment required to produce unit rotation in a joint.

– VWUXFWXUDO SURSHUWLHV (of a joint): Resistance to internal forces and moments in the connected

– members, rotational stiffness and rotation capacity.

XQLSODQDUMRLQW: In a lattice structure a uniplanar joint connects members that are situated in a single

– plane.

Joint = web panel in shear + connection Left joint = web panel in shear + left connection

Right joint = web panel in shear + right connection

a) Single-sided joint configuration b) Double-sided joint configuration

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a) Major-axis joint configurations

Double-sided beam-to-column Double-sided beam-to-beam

joint configuration joint configuration 0 0

b) Minor-axis joint configurations (to be used only for balanced moments = )

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(1) The following symbols are used in this Standard:

d is the nominal bolt diameter, the diameter of the pin or the diameter of the fastener;

d is the hole diameter for a bolt, a rivet or a pin ;

0

d is the hole size for the tension face, generally the hole diameter, but for horizontally slotted holes

o,t the slot length should be used;

d is the hole size for the shear face, generally the hole diameter, but for vertically slotted holes the slot

o,v length should be used;

d is the clear depth of the column web;

c

d is the mean of the across points and across flats dimensions of the bolt head or the nut, whichever is

m smaller;

f is the design value of the Hertz pressure;

H,Rd

f is the specified ultimate tensile strength of the rivet;

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e is the end distance from the centre of a fastener hole to the adjacent end of any part, measured in the

1 direction of load transfer, see Figure 3.1;

e is the edge distance from the centre of a fastener hole to the adjacent edge of any part, measured at

2 right angles to the direction of load transfer, see Figure 3.1;

e is the distance from the axis of a slotted hole to the adjacent end or edge of any part, see Figure 3.1;

3

e is the distance from the centre of the end radius of a slotted hole to the adjacent end or edge of any

4 part, see Figure 3.1;

is the effective length of fillet weld;

eff

n is the number of the friction surfaces or the number of fastener holes on the shear face;

p is the spacing between centres of fasteners in a line in the direction of load transfer, see Figure 3.1;

1

p is the spacing between centres of fasteners in an outer line in the direction of load transfer, see

1,0 Figure 3.1;

p is the spacing between centres of fasteners in an inner line in the direction of load transfer, see

1,i Figure 3.1;

p is the spacing measured perpendicular to the load transfer direction between adjacent lines of

2 fasteners, see Figure 3.1;

r is the bolt row number;

127(In a bolted connection with more than one bolt-row in tension, the bolt-rows are numbered

starting from the bolt-row furthest from the centre of compression.

V is the length of stiff bearing.

s

W is the thickness of the angle cleat.

a

W is the thickness of the column flange;

fc

W is the thickness of the plate under the bolt or the nut;

p

W is the thickness of the web or bracket;

w

W is the thickness of the column web;

wc

A is the gross cross-section area of bolt;

A is the area of the rivet hole;

0

A is the shear area of the column, see EN 1993-1-1;

vc

A is the tensile stress area of the bolt or of the anchor bolt;

s

A is the effective shear area;

v,eff

B is the design punching shear resistance of the bolt head and the nut

p,Rd

E is the elastic modulus;

F is the design preload force;

p,Cd

F is the design tensile force per bolt for the ultimate limit state;

t,Ed

F is the design tension resistance per bolt;

t,Rd

F is the tension resistance of an equivalent T-stub flange;

T,Rd

F is the design shear resistance per bolt;

v,Rd

F is the design bearing resistance per bolt;

b,Rd is the design slip resistance per bolt at the serviceability limit state;

F

s,Rd,ser

F is the design slip resistance per bolt at the ultimate limit state;

s,Rd

F is the design shear force per bolt for the serviceability limit state;

v,Ed,ser

F is the design shear force per bolt for the ultimate limit state;

v,Ed

M is the design moment resistance of a joint;

j,Rd

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S is the rotational stiffness of a joint;

j

S is the initial rotational stiffness of a joint;

j,ini

V is the plastic shear resistance of a column web panel;

wp,Rd

z is the lever arm;

µ is the slip factor;

φ is the rotation of a joint.

(2) The following standard abbreviations are used in section 7:

CHS for “circular hollow section”;

RHS for “rectangular hollow section”, which in this context includes square hollow sections.

λ

gap g overlap = (q/p) x 100 %

ov

g

g q

p

(a) Definition of gap (b) Definition of overlap

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(3) The following symbols are used in section 7:

L(L

$ is the cross-sectional area of member = 0, 1, 2 or 3);

i

$ is the shear area of the chord;

v

$ is the effective shear area of the chord;

v,eff

/ is the system length of a member;

0 is the design value of the resistance of the joint, expressed in terms of the in-plane internal moment

ip,i,Rd L

in member (L = 0, 1, 2 or 3);

0 L

is the design value of the in-plane internal moment in member (L = 0, 1, 2 or 3);

ip,i,Ed

0 is the design value of the resistance of the joint, expressed in terms of the out-of-plane internal

op,i,Rd L

moment in member (L = 0, 1, 2 or 3);

0 L

is the design value of the out-of-plane internal moment in member (L = 0, 1, 2 or 3);

op,i,Ed

1 is the design value of the resistance of the joint, expressed in terms of the internal axial force in

i,Rd L

member (L = 0, 1, 2 or 3);

1 L

is the design value of the internal axial force in member (L= 0, 1, 2 or 3);

i,Ed

: is the elastic section modulus of memberL (L = 0, 1, 2 or 3);

e L

: is the plastic section modulus of memberL (L = 0, 1, 2 or 3);

p L

E L

is the overall out-of-plane width of RHS member (L = 0, 1, 2 or 3);

i

E is the effective width for a brace member to chord connection;

eff

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E is the effective width for an overlapping brace to overlapped brace connection;

e,ov

E is the effective width for punching shear;

e,p

E is the width of a plate;

p

E is the effective width for the web of the chord;

w L

G is the overall diameter of CHS member (L = 0, 1, 2 or 3);

i

G is the depth of the web of an I or H section chord member;

w

H is the eccentricity of a joint;

I is the buckling strength of the chord side wall;

b

I is the yield strength of memberL (L= 0, 1, 2 or 3);

yi

I is the yield strength of a chord member;

y0

J J

is the gap between the brace members in a K or N joint (negative values of represent an overlap

T J

); the gap is measured along the length of the connecting face of the chord, between the toes

of the adjacent brace members, see Figure 1.3(a);

K L

is the overall in-plane depth of the cross-section of member (L = 0, 1, 2 or 3);

i

N is a factor defined in the relevant table, with subscript g, m, n or p ;

is the buckling length of a member;

S is the length of the projected contact area of the overlapping brace member onto the face of the

chord, in the absence of the overlapped brace member, see Figure 1.3(b);

T is the length of overlap, measured at the face of the chord, between the brace members in a K or N

joint, see Figure 1.3(b);

U is the root radius of an I or H section or the corner radius of a rectangular hollow section;

W is the flange thickness of an I or H section;

f

W L

is the wall thickness of member (L = 0, 1, 2 or 3);

i

W is the thickness of a plate;

p

W is the web thickness of an I or H section;

w is a factor defined in the relevant table; L

is the included angle between brace member and the chord (L = 1, 2 or 3);

i is a factor defined where it occurs;

— is a factor defined in the relevant table;

is the angle between the planes in a multiplanar joint.

(4) The integer subscripts used in section 7 are defined as follows:

L L= L

is an integer subscript used to designate a member of a joint, 0 denoting a chord and = 1, 2 or

L

3 the brace members. In joints with two brace members, = 1 normally denotes the

L= L

compression brace and 2 the tension brace, see Figure 1.4(b). For a single brace = 1

whether it is subject to compression or tension, see Figure 1.4(a);

L M L M

and are integer subscripts used in overlap type joints, to denote the overlapping brace member and to

denote the overlapped brace member, see Figure 1.4(c).

(5) The stress ratios used in section 7 are defined as follows:

Q I

is the ratio ( / ) / (used for RHS chords);

0,Ed y0 M5

Q I

is the ratio ( / ) / (used for CHS chords);