emi2015 presentation 02sina.sharif.edu/~dolatshahi/papers/conference/2015-emi-presentation-sl.pdfrbs...

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FINITE ELEMENT INVESTIGATION OF A NEW

STRUCTURAL SHEAR FUSES IN MOMENT

RESISTING FRAMES

By:Pouya Rezazadeh

(Sharif University of Technology)

Kiarash M. Dolatshahi

(Sharif University of Technology)

M. T. Nikoukalam (Presentor)

(University of Colorado Boulder)

J u n e 2 0 1 5

OUTLINE• Introduction• Motivation• Replaceable shear link in MRFs• Perforated and slit shear links• Summary and conclusion

FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMESM. T. Nikoukalam

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Introduction

M. T. Nikoukalam

• Of the most favorable lateral load resisting systems are Special Moment Resisting Frames (SMRFs) due to their high ductility and energy dissipation capacity.

• A minimum span-to-depth ratio of 7 in special MRFs and 5 in intermediate MRFs must be maintained (AISC 358-10)

• The span-to-depth ratio in Framed Tube structures is about 3.4-4.

FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES

Motivation

M. T. Nikoukalam

F F

Vpb1V

M

F F

V >Vpb2 pb1V

M

F F

V >V >Vpb3 pb2 pb1V

M

2FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES

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Motivation

M. T. Nikoukalam

(Photo by M.T.Nikoukalam)


Replaceable shear link in MRFs

M. T. Nikoukalam

Prefabricated in shop & shipped to site

On-site bolting of replaceable link

e

Replaceable Shear Link

Bolted End-PlateConnection

Stiffener Pls

BeamCL

• Replaceable shear link with solid web

•Slit shear link

•Perforated shear link


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Replaceable shear link in MRFsMethodology

M. T. Nikoukalam

-900

-600

-300

0

300

600

900

-0.15 -0.10 -0.05 0.00 0.05 0.10 0.15

Lin

kS

hea

r: V

(kN

)

Inelastic Rotation: γP (rad)

TestABAQUS

Vn

Vn

-800

-600

-400

-200

0

200

400

600

800

-0.15 -0.10 -0.05 0.00 0.05 0.10 0.15

Lin

kS

he

ar:

V (

kN

)

Inelastic Rotation: γp (rad)

TestABAQUS

-2.0

-1.0

0.0

1.0

2.0

-8 -6 -4 -2 0 2 4 6 8

No

rma

lize

dM

om

en

ta

tC

olu

mn

Fac

e(M

/Mp

n)

Story Drift (%)

TestABAQUS

Okazaki, M.D. Engelhardt (2007) Lee et al. (2005)

•Finite Element Modeling (Abaqus/CAE 6.13-1)


Replaceable shear link concept in MRFsDesign Concept

M. T. Nikoukalam

θp

1 θ > θp p

2 1

Drift

Base

she

ar

0

12

DriftElastic Rapid return

to occupancyCollapse prevention

Flexuralyielding

Base

she

ar

0

1

2

Shearyielding

(a)RBS

(b)Shear Link Frame (SLF)

(a)Hybrid Frame (HF)


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Replaceable shear link concept in MRFsFrames with shear fuse

M. T. Nikoukalam

(a) L/d=4 (b) L/d=5 (c) L/d=7


Replaceable shear link concept in MRFsAnalysis results

M. T. Nikoukalam

(I) Cyclic load-displacement curves

(II) Dissipated energy

(a) L/d=4 (b) L/d=5 (c) L/d=7

-2000

-1500

-1000

-500

0

500

1000

1500

2000

-6.0 -4.0 -2.0 0.0 2.0 4.0 6.0

Bas

e S

hea

r (k

N)

Story Drift (%)

Shear Link

RBS

-2000

-1500

-1000

-500

0

500

1000

1500

2000

-6.0 -4.0 -2.0 0.0 2.0 4.0 6.0

Bas

e S

hea

r (k

N)

Story Drift (%)

Shear Link

RBS

-2000

-1500

-1000

-500

0

500

1000

1500

2000

-6.0 -4.0 -2.0 0.0 2.0 4.0 6.0

Bas

e S

hea

r (k

N)

Story Drift (%)

Shear Link

RBS

0

2

4

6

8

10

12

14

0.0 1.0 2.0 3.0 4.0 5.0 6.0

Acc

um

ula

tiv

e E

ner

gy

Dis

sip

atio

n (

kN.m

m)

x 10

0000

Story Drift (%)

Shear Link

RBS

0

2

4

6

8

10

12

0.0 1.0 2.0 3.0 4.0 5.0 6.0

Acc

um

ula

tive

En

erg

yD

issi

pat

ion

(kN

.mm

)x

1000

00

Story Drift (%)

Shear Link

RBS

0

2

4

6

8

10

12

0.0 1.0 2.0 3.0 4.0 5.0 6.0

Acc

um

ula

tiv

e E

ner

gy

Dis

sip

atio

n (

kN.m

m)

x 10

0000

Story Drift (%)

Shear Link

RBS

0.0

1.0

2.0

3.0

4.0

5.0

0.0 1.0 2.0 3.0 4.0 5.0

(SL

F) P

E /

(RB

S) P

E

Story Drift (%)

L/D = 4

L/D = 5

L/D = 7

•Shear Link Frame (SLF)


-2000

-1500

-1000

-500

0

500

1000

1500

2000

-6.0 -4.0 -2.0 0.0 2.0 4.0 6.0

Bas

e S

hea

r (k

N)

Story Drift (%)

Shear Link

RBS

-2000

-1500

-1000

-500

0

500

1000

1500

2000

-6.0 -4.0 -2.0 0.0 2.0 4.0 6.0

Bas

e S

hea

r (k

N)

Story Drift (%)

Shear Link

RBS

-2000

-1500

-1000

-500

0

500

1000

1500

2000

-6.0 -4.0 -2.0 0.0 2.0 4.0 6.0

Bas

e S

hea

r (k

N)

Story Drift (%)

Shear Link

RBS

0

2

4

6

8

10

12

14

0.0 1.0 2.0 3.0 4.0 5.0 6.0

Acc

um

ula

tiv

e E

ner

gy

Dis

sip

atio

n (

kN.m

m)

x 10

0000

Story Drift (%)

Shear Link

RBS

0

2

4

6

8

10

12

0.0 1.0 2.0 3.0 4.0 5.0 6.0

Acc

um

ula

tive

En

erg

yD

issi

pat

ion

(kN

.mm

)x

1000

00

Story Drift (%)

Shear Link

RBS

0

2

4

6

8

10

12

0.0 1.0 2.0 3.0 4.0 5.0 6.0

Acc

um

ula

tiv

e E

ner

gy

Dis

sip

atio

n (

kN.m

m)

x 10

0000

Story Drift (%)

Shear Link

RBS

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Replaceable shear link concept in MRFsAnalysis results

M. T. Nikoukalam

•Hybrid Frame (HF)

(I) Load-displacment curves

(II) Cumulative dissipated energy

(a) L/d=4 (b) L/d=5 (c) L/d=7

-2500-2000-1500-1000

-5000

5001000150020002500

-6.0 -4.0 -2.0 0.0 2.0 4.0 6.0

Bas

e S

hea

r (k

N)

Story Drift (%)

RBS

Hybrid Frame

-2500-2000-1500-1000

-5000

5001000150020002500

-6.0 -4.0 -2.0 0.0 2.0 4.0 6.0

Bas

e S

hea

r (k

N)

Story Drift (%)

RBS

Hybrid Frame

-2500-2000-1500-1000

-5000

5001000150020002500

-6.0 -4.0 -2.0 0.0 2.0 4.0 6.0

Bas

e S

hea

r (k

N)

Story Drift (%)

0

2

4

6

8

10

12

14

0.0 1.0 2.0 3.0 4.0 5.0

Acc

um

ula

tiv

e E

ner

gy

Dis

sip

atio

n (

kN.m

m)

x 10

0000

Story Drift (%)

RBSHybrid FrameLinkBeam

0

2

4

6

8

10

12

0.0 1.0 2.0 3.0 4.0 5.0

Acc

um

ula

tiv

e E

ner

gy

Dis

sip

atio

n (

kN.m

m)

x 10

0000

Story Drift (%)

RBSHybrid FrameLinkBeam

0

2

4

6

8

10

12

0.0 1.0 2.0 3.0 4.0 5.0

Acc

um

ula

tive

En

erg

yD

issi

pat

ion

(kN

.mm

)x

1000

00

Story Drift (%)

RBS

Hybrid Frame

Link

Beam


Slit and perforated links

M. T. Nikoukalam

Model name

Perf 1 Perf 2 Perf 3 Perf 4

D/S 0.24 0.34 0.39 0.6

Vy(MPa) 316 291 278 221

Model name

SL 1 SL 2 SL 3 SL 4

b (mm) 28.13 27.73 27.50 27.72

l0 (mm) 36.54 39.06 40.44 51.34

Vy(MPa) 316 291 278 221

b

l0


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Slit and perforated links

M. T. Nikoukalam

•Damage Index (DI) Model

exp 1.5maxPEEQ = equivalent plastic strain, T = triaxiality ratio of hydrostatic stress to Mises stress)

(Chao, Khandelwal et al. (2006))


Slit and perforated linksVerification of model

M. T. Nikoukalam

-35-25-15

-55

152535

-0.15 -0.1 -0.05 0 0.05 0.1 0.15

Lin

k S

hea

r: V

(k

N)

Link Rotation: γ (rad)

test

Pre-DI=1.0

Post-DI=1.0

0.084 rad(DI = 1.51)

DI = 1.3

DI = 1.0

DI exceeding 1 at the cycle with maximum rotation of 0.07 rad (10cm)

Damage Index

0.0000.1260.2520.3780.5030.6290.7550.8811.0071.1331.2591.3841.510

(picture by courtesy of F. Albermani)


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Slit and perforated linksVerification of model

M. T. Nikoukalam

Damage Index

0.0000.0840.1670.2510.3350.4180.5020.5860.6690.7530.8370.9201.004

DI exceeding 1 at the cycle with maximum inelastic rotation of 0.09 rad

-800-600-400-200

0200400600800

-0.15 -0.1 -0.05 0 0.05 0.1 0.15

Lin

k S

hea

r: V

(k

N)

Inelastic Rotation: γ (rad)

Test

Pre-DI=1.0

Post-DI=1.0

0.12 rad

DI = 1.3

DI = 1.0

Damage Index

0.0000.1320.2650.3970.5300.6620.7950.9271.0601.1921.3241.4571.589

DI at the point of test failure (inelastic rotation = 0.12 rad) (picture by courtesy of T. Okazaki)


Slit and perforated linksResults

M. T. Nikoukalam

Vy/Vys = 0.83 Vy/Vys = 0.76 Vy/Vys = 0.73 Vy/Vys = 0.58

Rotation Perf1 SL1 Ratio Perf2 SL2 Ratio Perf3 SL3 Ratio Perf4 SL4 Ratio

0.006 0.006 0.061 0.102 0.008 0.061 0.129 0.009 0.082 0.115 0.007 0.075 0.093

0.015 0.022 0.167 0.129 0.028 0.171 0.163 0.029 0.230 0.127 0.023 0.241 0.095

0.046 0.080 0.621 0.128 0.098 0.638 0.153 0.107 0.850 0.126 0.090 0.895 0.100

0.080 0.165 1.020 0.161 0.190 1.043 0.182 0.204 1.357 0.150 0.177 1.496 0.118

0.129 0.299 1.404 0.213 0.331 1.413 0.234 0.359 1.830 0.196 0.401 2.018 0.199

•Link over-strength comparison

Why???? Why so low in perf?


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M. T. Nikoukalam

0

200

400

600

800

1000

0 0.05 0.1 0.15 0.2

En

erg

y (k

J)


Slit 2

Perf 2

-800-600-400-200

0200400600800

-0.2 -0.1 0 0.1 0.2

Lin

k S

hea

r: V

(kN

)


Slit 2Perf 2

•Dissipated energy comparison

Why????


Rotation Perf1 SL1 Ratio Perf/SL Perf2 SL2 Ratio Perf/SL Perf3 SL3 Ratio Perf/SL Perf4 SL4 Ratio Perf/SL

0.005 2.28 2.13 1.07 2.08 2.08 1.00 1.96 2.08 0.94 1.43 1.89 0.76

0.014 17.25 17.67 0.98 15.71 17.31 0.91 14.74 17.36 0.85 10.94 15.91 0.69

0.047 114.43 121.68 0.94 104.97 119.71 0.88 98.67 119.85 0.82 74.66 112.38 0.66

0.128 480.00 523.55 0.92 440.78 512.94 0.86 402.70 516.07 0.78 254.57 480.47 0.53

Total 878.82 1022.97 0.86 793.26 1006.47 0.79 677.97 1013.90 0.67 431.02 955.59 0.45



M. T. Nikoukalam

•DI comparison

Why???? So high in SLIT?????!!!!!!


Rotation Perf1 SL1 Ratio Perf/SL Perf2 SL2 Ratio Perf/SL Perf3 SL3 Ratio Perf/SL Perf4 SL4 Ratio Perf/SL

0.005 0.04 0.14 0.25 0.02 0.15 0.17 0.03 0.15 0.17 0.02 0.17 0.14

0.014 0.26 1.00 0.26 0.21 1.05 0.20 0.21 1.05 0.20 0.22 1.39 0.16

0.047 1.32 6.00 0.22 1.23 6.40 0.19 1.27 6.30 0.20 1.47 8.30 0.18

0.090 2.52 11.55 0.22 2.46 12.33 0.20 2.55 11.96 0.21 4.38 16.81 0.26

0.128 5.67 19.78 0.29 4.78 21.11 0.23 8.74 20.11 0.43 11.96 29.42 0.41

0

5

10

15

20

25

30

35

0 0.05 0.1 0.15 0.2

DI


Slit 2

Perf 2


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Summary• A new replaceable structural shear fuse is introduced and studied as an alternative to the traditional flexural fuse in moment resisting frames (MRFs)

• The new proposed shear fuse provides a high ductility capacity for MRFs, especially with low span-to-depth ratios.

• Comparing the results of RBS models revealed that frames with lower span-to-depth ratio have higher equivalent plastic strains (PEEQ) and shorter plastic hinges.

• Perforated and slit shear links are introduced as two alternative details for the shear link.

• Slit links showed higher over-strength, more energy dissipation, and higher damage index.

M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES

Thank You!

emi2015 presentation 02sina.sharif.edu/~dolatshahi/papers/conference/2015-emi-presentation-sl.pdfrbs...

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