PushOver

5/18/2018 PushOver

1/30Push-over analysis for seismic performance evaluation of RC frame structures. Computer programsPush-over analysis for seismic performance evaluation of RC frame structures. Computer programs

22ooCiclo de Palestras em Engenharia Civil-2003Ciclo de Palestras em Engenharia Civil-2003

12 de Novembro de 200312 de Novembro de 2003

niversidade Nova de !isboa-Centro de "nvestiga#ao em $struturas e Constru#%o-N"Cniversidade Nova de !isboa-Centro de "nvestiga#ao em $struturas e Constru#%o-N"C

Push-over analysis for seismicPush-over analysis for seismic

performance evaluation of RC frameperformance evaluation of RC framestructures. Computer programsstructures. Computer programs

Dr. C. G. ChioreanDr. C. G. Chiorean

Technical University of Cluj-Napoca, RomaniaTechnical University of Cluj-Napoca, Romania

Bolseiro na UNL!CT, Lis"oa, #ortu$alBolseiro na UNL!CT, Lis"oa, #ortu$al

5/18/2018 PushOver


Part "".Part "".Computer programsComputer programs

N$&C'(N$&C'( Computer program for large deflection elasto-plasticComputer program for large deflection elasto-plastic

analysis of spatial frame structuresanalysis of spatial frame structures

')$P')$P Computer program for inelastic analysis of arbitraryComputer program for inelastic analysis of arbitrary

reinforced and composite concrete sectionsreinforced and composite concrete sections

OutlineOutline

Part ".Part ".Push-over analysis for seismic performancePush-over analysis for seismic performance

evaluation of spatial RC frame structuresevaluation of spatial RC frame structures

5/18/2018 PushOver


)tatic Nonlinear)tatic Nonlinearanalysis -analysis -Push-over 'nalysisPush-over 'nalysis*apro+imative solution,*apro+imative solution,

Seismic performanceSeismic performance InelasticInelastic TypesTypes

of analysisof analysis

Nonlinear dynamic analysis- time history *final solution,Nonlinear dynamic analysis- time history *final solution,

Vb

!

Push-over Curve

"oadvs #eflection! $

Vb

5/18/2018 PushOver


Nonlinear static procedure: constant gravitational loads and

monotonically increasing lateral loads Plastic mechanisms and P-effects: diplacement or arc length

control

Capacity curve: Control node displacement vs base shear force

Lateral load patterns: uniform, modal, SRSS, L! force

distribution

stimation of the target displacement: elastic or inelastic response

spectrum for e"uivalent S#$! system

Performance evaluation: global and local seismic demands %ith

capacities of performance level&

Key elements of the push-over analysisKey elements of the push-over analysis

5/18/2018 PushOver


Concentrated plasticity #istributed plasticity

#imensionless plastic hinge

'nteraction surface

Return mapping plasticity

algorithms Computationally efficient but limitedaccuracy

Plastic (ones

!orce-strain curves: "uasi plastic hingeapproach

Stress-strain curves: fiber element approach Plastic flo% rules

)igh accuracy but computational e*pensive

Plastic hingePlastic (ones

lastic lastic

Inelastic analysis modelsInelastic analysis models

5/18/2018 PushOver


IP4IP3

IP2

j=IP5

iPI1

L+,

L+,

x

z

y

ConcreteSteel

Z

Yx

vi, Tiy

wi, Tiz

zj,Mzj

xj,Mxj

uj, Njvj, Tjy

yi,Myi

xi,Mxi

ui, Ni

zi,Mzi

wj, Tjz

z

y

N

y

!le*ibility-based nonlinear beam column element

'terative method to compute inelastic response at cross-sectional level inelasatic

fle*ural and a*ial rigidity.

/radual yielding along the member length and %ithin the cross sections

#istributed loads

0niform or nonuniform tapered. members

1ariation of reinforcement bars along the member

$ne element+

member

3D RC Fier !eam Column "lement3D RC Fier !eam Column "lement

5/18/2018 PushOver


N2

.

y

x

,,

yx

yxuxyu

+=

+=++=

2rbitrary cross-sections under bia*ial bending moments and a*ial force

2rc length icremental iterative method %ith tangent stiffness strategy/reen3s theorem: domain integrals are evaluated in terms of boundary integrals

4-N-curves, N-4*-4y interaction diagrams and a*ial force ultimate curvature

Inelastic analysis of cross-sectionsInelastic analysis of cross-sections

5/18/2018 PushOver


Large deflection and large rotations

/eometrical local effects P-. including bo%ing effect, shear deformations

Concentrated and distributed plasticity fiber and 4-N-aproaches.

Consistency bet%een linear and nonlinear models one element+member.

Local geometrical and material imperfections

!le*ible semi-rigid. and finite 5oints

Complete non-linear behavior pre and post crtical response: snap-bac6

and snap-through.

#odel capailities#odel capailities

5/18/2018 PushOver

9/30

Push-over analysis for seismic performance evaluation of RC frame structures. Computer programsPush-over analysis for seismic performance evaluation of RC frame structures. Computer programs

lastic spectrum response: 7ype 8

/round 7ype: 2

Desi$n $roun% acceleration& #G'().*$

+ass() )/ toneslevel

Case study $Si% story RC frame uildin&'Case study $Si% story RC frame uildin&'

9 *9

; *

5/18/2018 PushOver

10/30


Pushover loads =mode 8 transv&>

ffective modal mass?9

ffective modal mass?A9@

Base shear forces:7ransversal mode 8.: !(? ;D 6N

Longitudinal mode 8.:!*? D 6N

78?8&

5/18/2018 PushOver

11/30


Plastic hinge analysis Plastic (one analysis

'nteraction surface e"uation: Stress-strain curves for concrete andsteel bars urocodes.

A /auss-Lobatto 'P+member

%nteraction !-&

-2000

0

2000

4000

6000

8000

10000

12000

0 200 400 600 800 1000 1200

Bendi ng moment (kNm)

-2000

0

2000

4000

6000

8000

10000

12000

0 .0 0 0. 01 0. 02 0. 03 0. 04 0 .0 5

ltimate curvature

'(ialforce)*!+

-1000.00

0.00

1000.00

2000.00

3000.00

4000.00

5000.00

0 .0 0 10 0.0 0 2 00 .0 0 3 00 .0 0 4 00 .0 0

Bending Moment (kNm)

ajor axis

bending

Minor axis

bending

0.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

0.00 0.05 0.10 0.15 0.20

Ultimate curvature

Major axis

bending

Minor axis

bending

:8

9&89&8

=

+

zp

z

py

y

M

M

M

M

D

;*

5/18/2018 PushOver

12/30


Plastic (one analysis Plastic hinge analysis

Pushover curves-"ongitudinal direction

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0.00 20.00 40.00 60.00 80.00 100.00 120.00#isplacement , )cm+

'pliedloadfactor

Plastic zone, Plim1.12

Plastic !inge, Plim1.11

(ushover analysis) *on&itudinal direction(ushover analysis) *on&itudinal direction

Plastic hinge: CP0 time: 8&< min

8 load cycles.

Plastic (one: CP0 time: D&; min

8

5/18/2018 PushOver

13/30


Plastic hinge analysisPlastic (one analysisPushover curves-ransversal direction

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0.00 20.00 40.00 60.00 80.00#isplacement )cm+

'plied

load

factor Plastic zone, Plim1.21

Plastic !inge, Plim1.11

(ushover analysis) Transversal direction(ushover analysis) Transversal direction

5/18/2018 PushOver

14/30


Bending moments !le*ural rigidities

(lastic +one analysis) *on&itudinal direction(lastic +one analysis) *on&itudinal direction

5/18/2018 PushOver

15/30


Bending moments !le*ural rigidities

(lastic +one analysis) Transversal direction(lastic +one analysis) Transversal direction

5/18/2018 PushOver

16/30


Pushover curves-ransversal direction

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0.00 20.00 40.00 60.00 80.00#isplacement )cm+

'pliedloa

dfactor Plastic zone "modal #attern$, #lim1.21

Plastic zone "%ni&orm acceleration$, #lim1.1'

#odal vs ,niform force distriution#odal vs ,niform force distriution

5/18/2018 PushOver

17/30


Pushover curves-"ongitudinal direction

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0.00 20.00 40.00 60.00 80.00 100.00 120.00#isplacement , )cm+

'pliedloa

dfactor

Plastic zone "modal #attern$, Plim1.12

Plastic zone "%ni&orm #attern$,Plim1.28

#odal vs ,niform force distriution#odal vs ,niform force distriution

5/18/2018 PushOver

18/30


"uivalent SDOF and tar&et displacement"uivalent SDOF and tar&et displacement

5/18/2018 PushOver

19/30


arget displacements )Plastic /one+-ransversal direction

(t).80 cm

(t15.)) cm

(t31.54 cm

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0.00 20.00 40.00 60.00 80.00

#isplacement . )cm+

'pliedlo

adfactor *om#%ted #%s!o+er c%r+e "#lastic zone$

dealized elaso-#er&ectl #lastic "*8$

Tar&et displacements) transversal directionTar&et displacements) transversal direction

5/18/2018 PushOver

20/30


arget displacem ents )plastic hinge+-ransversal direction

).45

14.'1

2'.83

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0.00 10.00 20.00 30.00 40.00 50.00 60.00#isplacement )cm+

'pliedlo

adfactor

*om#%ted #%s!o+er c%r+e "#lastic !inge$

dealized elasto-#er&ectl #lastic "*8$

P/0.15g

P/0.3g

P/0.6g

Tar&et displacements) transversal directionTar&et displacements) transversal direction

T t di l t l it di l di ti

5/18/2018 PushOver

21/30


arget displacements )plastic /one+-"ongitudinal direction

11.65 cm

23.3 cm

46.64 cm

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0.00 20.00 40.00 60.00 80.00 100.00 120.00#isplacement , )cm+

'pliedloadfactor

*om#%ted #%s!o+er c%r+e "#lastic zone$


P/0.15g

P/0.3g

P/0.6g

Tar&et displacements) lon&itudinal directionTar&et displacements) lon&itudinal direction

T t di l t l it di l di ti

5/18/2018 PushOver

22/30


arget displacements )plastic hinge+-"ongitudinal direction

11.2) cm

22.54 cm

45.08 cm

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0.00 20.00 40.00 60.00 80.00 100.00#isplacement , )cm+

'pliedloa

dfactor

*om#%ted #%s!o+er c%r+e "#lastic !inge$


P/0.15g

P/0.3g

P/0.6g

Tar&et displacementsTar&et displacements lon&itudinal directionlon&itudinal direction

5/18/2018 PushOver

23/30


*ocal seismic demands*ocal seismic demands

Curvatures along the member length

-0.0150

-0.0100

-0.0050

0.0000

0.0050

0.0100

0.0150

0.0200

0.00 1.00 2.00 3.00 4.00 5.00 6.00 ).00

Member lengt! "m$

*%r+at%res

P/0.15g

P/0.3g

P/0.6g

5/18/2018 PushOver

24/30


*ocal seismic demands*ocal seismic demands

Curvatures along the member length

-0.00)0

-0.0060

-0.0050

-0.0040

-0.0030

-0.0020

-0.0010

0.0000

0.0010

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50

Member lengt! "m$

*%r+at%res

P/0.15g

P/0.3g

P/0.6g

5/18/2018 PushOver

25/30


.loal seismic demands.loal seismic demandsP/2?&8

5/18/2018 PushOver

26/30


P/2?&;g P/2?&9gP/2?&8

5/18/2018 PushOver

27/30


P/2?&;g P/2?&9gP/2?&8

5/18/2018 PushOver

28/30


CollapseP/2?&8

5/18/2018 PushOver

29/30


P/2?&8

5/18/2018 PushOver

30/30

Push over analysis for seismic performance evaluation of RC frame structures Computer programsPush over analysis for seismic performance evaluation of RC frame structures Computer programs

2 computational efficient ;-# RC fiber beam-column element %as

developed and implemented in a nonlinear inelastic analysis computer

program Plastic hinge analysis: limited accuracy

2 pushover e*ample for spatial model %as presented in con5unction

%ith CD provisions

Pushover analysis: good estimates of global and local inelastic

deformations demands

Limitations: for structures that vibrate primarily in the fundamental

mode

$vercomes: adaptive force distribution and modal pushover analysis

procedures

Nonlinear dynamic analysis: final solution

Concludin& remar/sConcludin& remar/s

PushOver

Documents

Transcript of PushOver