07 Eurocodes Steel Workshop WEYNAND

8/21/2019 07 Eurocodes Steel Workshop WEYNAND

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Design of Structural

Steel Joints

Dr. Klaus WeynandFeldmann + Weynand GmbH, Aachen, Germany

Prof. Jean-Pierre JaspartUniversity of Lige, Belgium


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Steel Joints Introduction

Integration of joints into

structural design process Moment resistant joints

Simple joints

Design tools


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Steel Joints

Introduction Integration of joints into

structural design process

Moment resistant joints

Simple joints

Design tools


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Eurocodes - Design of steel buildings with worked examples Brussels, 16 - 17 October 2014

EN 1993 Part 1.8

Chapter 1 Introduction

Chapter 2 Basis of design

Chapter 3 Connections made with bolts, rivets or pinsChapter 4 Welded connections

Chapter 5 Analysis, classification and modelling

Chapter 6 Structural joints connecting H or I sections

Chapter 7 Hollow section joints


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Design of simple joints

ECCS Publication No 126 (EN)

Background information Design guidelines


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2 Basis of design Partial safety coefficients


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3 Connections made mechanical fasteners


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4 Welded connections


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structural design process Moment resistant joints

Simple joints

Design tools


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Actual joint response


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Actual joint response

M

M Rd

S j,inicd


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Influence on the structural response

Displacements

Internal forces

Failure mode and failure load


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M

M

?

?

?

M

Characterization

Modelling

Classification

Idealization

Four successive steps for structural integration


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Characterization

Search for a unified approach whatever the material

M

?

?

?


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Various configurations (1)Continuity

Beam-to-beam

Column bases


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Various configurations (2)

Joints in portal frames


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Various configurations (3)

Connections and joints in

composite construction


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Various cross-section shapes (1)

Hot-rolled and

cold-formed


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Various cross-section shapes (2)

Built-up profiles


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Various connection elements

Splices

Cleats

End plates


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Economy

Reduced fabrication, transportation and erection costs


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Specific design criteria

Robustness

Joints as key elements


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Characterization (1)

Search for a unified approach

M

?

?

?


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Eurocode 3 Part 1-8

Beam-to-beam joints, splices, beam-to-column joints and column

bases: welded connections

bolted connections (anchors for column bases)

Background: COMPONENT METHOD


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Three steps

First step

Identification of theactive components

Second step:

Response of the

components

Third step:

Assembly of the

components

F F F

E k1 E k2 E k3

F1,RdF2,Rd

F3,Rd

column webin shear

column webin tension

column webin compression

M

Sj,ini

Mj,Rd

cd

, ,minj Rd i RdM F z 2

, 1j ini

i

E zS

k

Characterization (3) - component method


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Characterization (4) - component method

EC3 Part 1-8 provides therefore:

a library of components

rules for the evaluation of the properties of the components(stiffness, resistance, deformation capacity)

rules for the evaluation of the possible component interactions

assembly rules for components

Applicable for simple joint and moment resistant joint


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Hollow section joints

Different approach for lattice girder joints

For many types of joint configurations:

Joints considered as a whole

Check of relevant failure modes Scope of application to be checked


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M

M

?

?

?

M

Characterization

Modelling

Classification

Idealization



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Classification (1)

Stiffness

Sj,ini

Pinned

Semi-rigid

RigidM

Boundaries for stiffness

Joint initial stiffness

Semi-rigid

Rigid

Pinned

Classification boundariesInitial joint stiffness


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Classification (2)

Resistance

Mj,Rd

Partial-strength

Full-strength

Pinned

Mj

Boundaries for strength

Joint strength

Full resistance

Partial resistance

Pinned

Classification boundariesJoint resistance


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Classification (3)

Ductility

Brittle

Semi-ductile Ductile

Mj


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M

M

?

?

?

M

Characterization

Modelling

Classification

Idealization



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Modelling

JOINTMODELLING

BEAM-TO-COLUMN JOINTSMAJOR AXIS BENDING

BEAMSPLICES

COLUMNBASES

SIMPLE

SEMI-

CONTINUOUS

CONTINUOUS


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M

M

?

?

?

M

Characterization

Modelling

Classification

Idealization



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Simple joints

Design tools


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ExampleSingle sided beam-to-column joint configuration, bolted end-plate connection

+ +

+ +

M

V

15

3

PE220

EB140

120

60 10

8030 30

240

4 M16 8.8

140

u=10=60

5

w=

To be evaluated:

Design moment resistance , initial stiffness

0

1

1,01,0

M

M

Material: S 235


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General data

2 2 140 2 12 2 12 92wc c fc ch h t r mm

2

2 2

4295,6 2 140 12 7 2 12 12 1307,6vc c c fc wc cA A b t t r

mm

80 70,8 0,8 12 26,9

2 2

fc

c

w tm r mm

140 8030

2 2

cb we mm

2 2

,

0

12 2350,25 0,25 8460 /

1,0

fc yc

pl fc

M

t fm Nmm mm

Column

Equivalent T-stub in tensionFt

m e

leff


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General data

+ +

+ +

15

3

IPE220120

60 10

8030 30

240

4 M16 8.8

140

u=10=60

5

w=

9,2220 10 60 165,4

2 2

fb

b

tz h u p mm

6,

,

0

285.406 235 10(classe 1 section) 67,07

1,0

pl yb yb

c Rd

M

W fM kNm

Lever arm

Beam


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General data

2 2

,

0

15 2350,25 0,25 13.218 /

1,0

p yp

pl p

M

t fm Nmm mm

mp

mp2

80 5,90,8 2 0,8 2 3 33,66

2 2

wbp w

w tm a mm

2 0,8 2 60 10 9,2 0,8 2 5 35,14p fb fm p u t a mm

140 8030

2 2

p

p

b we mm

End plate


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General data

5,5

1

33,660,53

33,66 30

p

p p

m

m e

22 35,14 0,55

33,66 30p

p p

mm e

Alpha factor for effective lengths

End plate


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General data

3

,0,9 0,9 800 157 10 90,43

1,25

ub st Rd

Mb

f AF kN

3

,

0,6 0,6 800 157 10(shear plane in thread) 60,3

1.25

ub sv Rd

Mb

f AF kN

1

0,5 12 15 10 14,8 2 4 47,42

b fc p bolt nut L t t h h mm

Bolts


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Component No 1

Column web in shear

Vwp

Vwp

F

M

z

F

3

,,

0

0,9 0,9 1307,6 235 10 159,7

3 3 1,0vc y cw

wc Rd

M

A fV kN

Assumption : 1

,

,1

159,7

159,71

wc Rd

Rd

V

F kN

1

0,38 0,38 1307,63,004

1 165,4

vcAk mmh

Resistance

Stiffness coefficient

Transformation parameter


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Component No 2

Column web in compression

, , min 2 2 2 5 ; 2 5

min 9, 2 2 5 2 2 15 5 12 12 ; 9, 2 5 2 15 10 5 12 12 161, 27

eff c wc fb f p fc fb f p fcb t a t t s t a t u t s

mm

, ,Assumption : min 1,0; 1,7 / 1,0wc com Ed y wck f

, , ,

2

161,27 92 2350,932 0,932 0,543 0,673 1,0

210000 7 7

eff c wc c y wc

p

wc

b d f

E t

1 2 2

, ,

1 10,713

1 1,3 161,27 7 1307,61 1,3 /eff c wc w c vcb t A

3

,2 , , , 1/ 1 0,713 1 161,27 7 235 10 1,0 189,1Rd wc eff c wc wc y wc MF k b t f kN

Resistance

Reduction factors to account for compression stresses and instability


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Component No 2

Column web in compression

F

F k Ei i i

, ,

2

0,7 0,7 161,27 78,589

92

eff c wc wc

wc

b tk mm

h



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Component No 3

Column web in tension

, , min 2 ; 4 1,25 min 2 26,9;4 26,9 1,25 30 145,10eff t wcb m m e mm

1 2 2

, ,

1 10,749

1 1,3 145,1 7 1307,61 1,3 /eff t wc wc vcb t A

3

,3 , , , 0/ 0,749 145,1 7 235 10 1,0 178,7Rd eff t wc wc y wc MF b t f kN

, ,

3

0,7 0,7 145,1 77,728

92

eff t wc wc

wc

b tk mm

h

Resistance



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Equivalent T-stub in tension

Component No 4

Column flange in bending

Component No 5 End plate in bending

F /4t

Ft

F /4t

F /4t

F /4t

m e

leff


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T-stub

Effective length

Distinction between circular and non-circular yield line patterns

Circular patterns Non-circular patterns


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T-stub

Effective length

Groups effects to consider in addition to the individual response of each bolt-row

Group 1+2 Group 2+3 Group 1+2+3

Row 1

Row 2

Row 3


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T-stub

Effective length

Groups effects to consider in addition to the individual response of each bolt-row

Row 3

,3 ,3, ,3, ;( )

Rd Rd indiv Rd groupF min F F


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Bolt rows consideredIn this example: only bolt row 1 is considered for tension forces

+ +

+ +

M

V

15

3

PE220EB140

120

60 10

8030 30

240

4 M16 8.8

140

u=10=60

5

w=

Row 1

Row 2


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Component No 4


, , , , 145,1 (see column web in tension)eff t fc eff t wcl b mm

min ;1, 25 ; / 2 min 30;1, 25 26,9;30 30pn e m b w mm

Resistance


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3

, , , , 3, , 2

2 2 2 145,1 8460 2 90,4 10 30 10 138,5

26,9 30eff t fc pl fc t Rd

fc Rd t

l m B nF kN

m n

, , 3 ,2 2 90,43 180,9fc Rd t t RdF B kN

Mode 1 - Complete yielding of the flange

Mode 2 - Bolt failure with yielding of the flange

Mode 3 - Bolt failure

Component No 4


, , , 3

, , 1

4 4 145,1 846010 182,5

26,9

eff t fc pl fc

fc Rd t

l mF kN

m


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Component No 4


,4 , , 1 , , 2 , , 3min ; ; 138,5Rd fc Rd t fc Rd t fc Rd tF F F F kN

3 3, ,

4 3 3

0,9 0,9 145,1 12

11,5926,9

eff fc t fcl t

k mmm

Resistance



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Component No 5

End plate in bending

, , min 2 ; min 2 33,66; 5,5 33,66 185eff t p p pl m m mm

min ;1,25 ; min 30;1,25 33,66;30 30p p pn e m e mm

, , , 3

, ,1

4 4 185 13.218Mode 1: 10 291

33,66

eff t p pl p

ep Rd

p

l mF kN

m

3, , , , 3

, ,2

2 2 2 185 13.218 2 90,43 10 30Mode 2: 10 162,1

33,66 30

eff p t pl p t Rd p

ep Rd

p p

l m B nF kN

m n

,5 , ,1 , ,2 , ,3min ; ; 162,1Rd ep Rd ep Rd ep RdF F F F kN

Resistance


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Component No 5


3 3, ,

5 3 3

0,9 0,9 185,0 1514,73

33,66

eff t p p

p

l tk mm

m



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Component No 7

Beam flange and web in compression

,7 , 367,07

/ 318,2210,8 10

Rd c Rd b fbF M h t kN

7k

Resistance



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Component No 8

Beam web in tension

, , , , 185eff t wb eff t pb l mm

3

,8 , , 0/ 185 5,9 235 10 1, 0 256,5Rd eff t wb wb yb MF b t f kN

8k

Resistance



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Component No 10

Bolts in tension

,10 ,2 2 90,43 180,9Rd t RdF B kN

10

1571,6 1,6 5,30

47,4

s

b

Ak mm

L

Mode 3 in T-stubs for components:

column flange in bending

end plate in bending

Resistance



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Mj,Rd

Design moment resistance

,min 138,5 (Column flange in bending)Rd Rd iF F kN

3

, 138,5 165,4 10 22,91j Rd RdM F z kNm

, , ,

215,27

3j el Rd j RdM M kNm

Design plastic moment resistance

Relevant component

Design elastic moment resistance


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Stiffness

Sj,ini2 6

2

,

210000 165,4 10/ 1 6234 /

1 1 1 1 1 1

3,004 8,589 7,728 11,59 14,73 5,30

j ini i

i

S E h k kNm rad

, / 2 3117 /j j iniS S kNm rad

Initial stiffness

Secant stiffness


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Design moment-rotation characteristic

M

Sj,ini

Sj,ini

SjS

j= /

Ersatzsteifigkeit:

Mj,Rd

2/3Mj,Rd

Secant stiffness


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Steel Joints

Introduction




Simple joints

Design tools


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Nominally pinned joints

Braced frame


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Nominally pinned joints

V 0 M = 0


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Design of simple joints

ECCS Publication No 126 (EN)

Background information

Design guidelines


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Classification and modelling of joints

Limits for classification of joints by stiffness

Nominally pinned

Semi-rigid

RigidMj

Initial stiffness of the joint

Sj,ini


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Sj,ini

Limits for classification of joints by stiffness

Nominally pinned

Semi-rigid

RigidMj

Initial stiffness of the joint

Semi-rigid joints :


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As an alternative to a semi-continuous modelling (semi-rigid joints), is it safe to

model the joints as nominally pinned whilst they are actually semi-rigid?

Semi-rigid Sj,ini> 0,5EIb/Lb

Partial strength Mj,Rd> 0,25 Mfull-strength

Nominally pinned Sj,ini= 0

Nominally pinned Mj,Rd= 0??


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Yes, under the reservation the joint has:

a sufficient rotation capacity

= capacity to rotate

a sufficient ductility

= capacity to follow the actual

loading path in a ductile way

VRd

V

MYielding criterionMRd

Supposed

loading path

Actual loading

path


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Supplementary design requirement

Sufficient resistance to catenary effects so as to provide required structural

robustness


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Example: Partial depth end-plate

Components

Bolts in shear

End-plate in bearing

End-plate in shear (gross section)

End-plate in shear (net section)

End-plate in shear block

End-plate in bending

Beam web in shear Welds in shear

Column flange in bearing


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Partial depth end-plate

Strength requirement

Use of component method for the assessment of VRd

Assessment of the strength of all the constitutive

components of the joint

+

Assembly of these components


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Rotation capacity requirement

Bending moment

Rotationavail

Contact between

supported beam and

supporting element

Compression force

Bending

moment

Bolts in tension


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Rotation capacity requirement

hp

he

tp

hbdb

avail

p bh d

p

availe

t

h


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Ductility requirement

Prevent premature fracture of the bolts

Prevent premature fracture of the welds

under unavoidable bending moment in the joint


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Ductility requirements

Prevent premature collapse of the bolts

2,8 yp

p ub

fd

t f

2,8 ycf

p ub

fd

t f for the supporting column

d and fub : diameter and tensile strength of bolts

for the end-plate

Yielding of end-plate prior to tensile fracture of bolts


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Steel Joints

Introduction




Simple joints

Design tools


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Practical design tools

Tables of standardized joints

Dedicated software


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Worked Example Configuration Beam IPE 500

Column HEA 340

End plate connection

Design assumption

Rigid joint

Frame analysisMEd = 220 kNm

CoP software used for this example: http://cop.fw-ing.com


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Design resistance: MRd = 196 kNm < 220 kNm

Classification: Semi-rigid

Failure mode: Column web in compression


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Failure mode:



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Failure mode:

Column web panel in shear


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Failure mode:



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Failure mode:



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Steel Joints

Dr. Klaus WeynandFeldmann + Weynand GmbH, Aachen, Germany

Prof. Jean-Pierre JaspartUniversity of Lige, Belgium

Documents

07 Eurocodes Steel Workshop WEYNAND