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1 Analytical Method for Calculating the Reduction in Strength Due to Shear Lag Effect in Tension Member Connections SSEF Architecture and Engineering Educators Meeting 2008 February 29 - March 1, 2008, Novotel Toronto Centre Hotel Dominique Bauer Novotel Toronto Centre Hotel Toronto, Ontario February 29 - March 1, 2008 SSEF Architectural and Engineering Educator's Meeting 2008 2

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Page 1: Analytical Method for Calculating the Reduction in ...profs.etsmtl.ca/dbauer/references/bauer_2008_analytical_method... · Analytical Method for Calculating the Reduction in Strength

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Analytical Method for Calculating the Reduction in Strength Due to Shear Lag Effect in Tension Member Connections

SSEF Architecture and Engineering Educators Meeting 2008February 29 - March 1, 2008,Novotel Toronto Centre Hotel

Dominique Bauer

Novotel Toronto Centre HotelToronto, Ontario

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 2

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February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 3

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 4

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11 000 kN Universal

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 5

Universal Testing Machine

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 6

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February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 7

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 8

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February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 9

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 10

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L = 100 mmLoad = 350 MPa

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 11

von Mises stresses

50 mm30° 30°

200 mm

100 mm30°

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 12

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beff

Critical Section

Fy

Gusset Plate

30°L

Tension Member

30°

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 13

Ty

wTension Member

L2 tan θ

σ2

σ3

σ4

L1 tan θ

θL2

dL

σ2 σ1

σ2

θ

Critical Section

dL

L1

σ1

qq

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 14

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σ

L tan θ T

x tan θ

θ

dxL

y’, y

L

x

Critical Section

1α =

Critical Section α

θ

1α =

elementalα

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 15

x x

Fy

(a) σ (b)

a

(c)

Fy

Fu

σ σ

L

Critical Section

θ θθ

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 16

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55

44

θ55

Stress resultant

Critical Section

11L

θ

33

22

44

θ

θ332211

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 17

w

w

cLθ

σc tan θ

(c – L) tan θ

L1 1

L

c

σ

c tan θy

θ

3 3

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 18

θ

L Ly

c

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Critical Section

Fu

L tan 30°

Fu

Critical Section

L

θ L θ

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 19

w w

Elements connected by a single longitudinal weld

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 20

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L1

Critical Section

θ

FuL1 tan θ

θL

Fu F2

L1 L2θ θ

θ θ

Fu F2

L1 tan θ

w

L2 L12

L2θ θ

w w

CriticalFu

F

L1 tan θ L1 tan θ

F

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 21w w

L1

Critical Section

Fu

L1L2

L2

θ θθ θ

Fu

L = 50 mmLoad = 200 MPa

F.E.A.

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 22

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L = 100 mmLoad = 200 MPa

F.E.A.

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 23

L = 200 mmLoad = 200 MPa

F.E.A.

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 24

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Elements connected by longitudinal welds along two parallel edges

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 25

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 26

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February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 27

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 28

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February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 29

σmaxσmax

Angle

CompressionTension T

L

Shear Flow, qGusset

Weld

2h/3

xp

My

CompressionTensionR

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 30

2h/3

h/3

h b1b2

Weld

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a b cτ

τ

σ

σO

Compressionσ

σ

τ

σ

τ τ

Tension

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 31

Element a

Element b

Element c

a

> 45º

b c

= 45 º < 45 º

Principal Directions from Mohr’s Circles

<45º> 45º = 45 º

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 32

Principal Directions from ANSYS

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Line of Action of Line of Action of

xp

y

ypx

Load in AngleLine of Action of

Reaction in Gusset

TG

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 33

Neutral AxisMy

yxp

Principal Axis of SectionLoad Axis

α

Neutral Axis

Centroïd f A l

xMx

G

Centroïd of Gusset

β

yp

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 34

of Angleof Gusset Plate

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Deflection

DeflectionTorsion

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 35

Angle

xp

xT T

xp

y z

M < T. xp

My = T. xp = constant

First Order Analysis

M < T xSecond Order

Analysis

z

z

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 36

My < T. xpAnalysis My = T. xp

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AngleCentroïdxAngle

xpxpTTT

xp1

xpT

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 37

Axe de la membrure principale

xp (+)xp (–)

E t i ité iti E t i ité é ti

Lignes de travail

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 38

Excentricité positive Excentricité négative

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Moment maximumau noeud dû à la rigidité de la diagonale

Membruresupérieure

Moment fléchissant le

long de la diagonale

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 39

TractionCompression Diagonales

Contraintes résiduelles de

traction

Tr

Contraintes résiduelles de

i

Section critique

++

–Contraintes dues au

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 40

compression(Réserve)Tr

refroidissement différentiel

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σT

z

É l

Loi de Hooke pour une pièce confinée :1) coefficient de Poisson connu2) σy connu en fonction de σz (σy = υσz)

1

Section critique

σz1

σz2

σy2σz3

1Fy

23

Fy

σy

σz

Étranglement amplifié de la section

y2

3 σy3

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 41

Critère de von MisesÉtat des contraintes

Acknowledgments

The present research was made possible by grants from :grants from :

• Steel Structures Education Foundation of the Canadian Institute of Steel Construction

• National Sciences and Engineering Research Council of Canada (No 238967-01)

• École de technologie supérieure

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 42

• École de technologie supérieure

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Center of Gravity

Length of Shear Lag

Tension Force, T

Gravity

S tTension Stresses

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 43

Support

Outstanding Leg

Length of Shear Lag

T

C t d

± 0,65 T

Tension

± 0,35 T

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 44

Connected Leg

Tension Stresses

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St-Venant Uniform Strain St-VenantT T

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 45

Bar

Uniform Shear Flow

Non-uniform Shear Flow

Non-uniform Shear Flow

T

Supporting Member

February 29 - March 1, 2008SSEF Architectural and Engineering Educator's Meeting 2008 46

T