Nonlinear Modeling With OpenSees

 Nonlinear Modeling with OpenSees

 Nonlinear Modeling with OpenSees

SE220 Fall 2015

SE220 Fall 2015

Instructor: Professor il!erto Mos"ueda

Instructor: Professor il!erto Mos"ueda

#utorial !$ %lire&a Sare!anha

#utorial !$ %lire&a Sare!anha

'( San )iego

'( San )iego

Material used for this presentation are mostly from OpenSees

Material used for this presentation are mostly from OpenSees

website/command manuals and SE201B Lecture Notes by rof! "onte!

OpenSees

OpenSees

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OpenSees is a software fra*ewor+ for !uilding finite ele*ent applications in

OpenSees is a software fra*ewor+ for !uilding finite ele*ent applications in

structural and geotechnical s$ste*s,

structural and geotechnical s$ste*s,

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•

#hese applications run on !oth se"uential- parallel- and distri!uted co*puter

#hese applications run on !oth se"uential- parallel- and distri!uted co*puter

s$ste*s,

s$ste*s,

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•

%

% fra*ewor+ IS a set of

fra*ewor+ IS a set of cooperating software co*ponents for !uilding

cooperating software co*ponents for !uilding

applications in a specific do*ain,

applications in a specific do*ain,

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#he OpenSees fra*ewor+ is written pri*aril$ in the o!.ect oriented language

#he OpenSees fra*ewor+ is written pri*aril$ in the o!.ect oriented language

(// though other languages na*el$ ( and

(// though other languages na*el$ ( and Fortran are also used,

Fortran are also used,

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Eisting Softwares short co*es:

Eisting Softwares short co*es:

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 E*!edding of co*putational procedures in codes *a+es it difficult to eperi*ent

 E*!edding of co*putational procedures in codes *a+es it difficult to eperi*ent

3integration sche*es- algorith*s- sol4ers and ta+e ad4antage of co*puting

3integration sche*es- algorith*s- sol4ers and ta+e ad4antage of co*puting

technolog$ 3Parallel 6 rid (o*puting

technolog$ 3Parallel 6 rid (o*puting

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7(losed8source9wasis the nor*- whereas other fields ha4e adopted 7open8

7(losed8source9wasis the nor*- whereas other fields ha4e adopted 7open8

source9software for co**unitiesof users, (losed source is an i*pedi*ent to new

source9software for co**unitiesof users, (losed source is an i*pedi*ent to new

research, No sharing of code- !uilding upon others ideas,

)ownload and Install OpenSees 6 #cl

)ownload and Install OpenSees 6 #cl

http:opensees,!er+ele$,edu

http:opensees,!er+ele$,edu

%fter downloading the #cl#+ eecuta!le $ou will need to run it to install t %fter downloading the #cl#+ eecuta!le $ou will need to run it to install t hehe );;<s on $our co*puter, %

);;<s on $our co*puter, %s can !e seen s can !e seen in the downloading section of in the downloading section of thethe etting Started Manual

etting Started Manual $ou will !e as+ed were to install the $ou will !e as+ed were to install the files, (urrentl$files, (urrentl$ the default is (:=tcl, It is essential that $ou change this to

the default is (:=tcl, It is essential that $ou change this to"C:\Program"C:\Program Files\Tcl"

Files\Tcl" during the course of the installat during the course of the installat ion, If when $ou start OpenSees-ion, If when $ou start OpenSees-$ou see an error *essage to the effect- >(annot find tcl?5,dll>-

$ou see an error *essage to the effect- >(annot find tcl?5,dll>- $ou ha4e$ou ha4e s+ipped this step and *ust reinstall tcl,

s+ipped this step and *ust reinstall tcl, Note that $ou wil pro!a!l$ ha4e toNote that $ou wil pro!a!l$ ha4e to uninstall the 4ersion $ou .ust installed first,

OpenSees Interpreters

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#he OpenSees interpreters are tcl interpreters which

ha4e !een etended to include co**ands for finite

ele*ent anal$sis:

1, Modeling @create nodes- ele*ents- loads and constraints

2, %nal$sis @specif$ the anal$sis procedure,

A, Output specification @specif$ what it is $ou want to

*onitor during the anal$sis,

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Being interpreters- this *eans that the files $ou create

and su!*it to the OpenSees interpreters are not input

files, Cou are creating and su!*itting PDOD%MS,

Materials

%nal$sis

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(onstraint co**and

#he (onstraint andler o!.ect deter*ines how the constraint e"uations are enforced in the anal$sis,

(onstraint e"uations enforce a specified 4alue for a )OF- or a relationship !etween )OFs,

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 Nu*!erer co**and

#he )OFNu*!erer o!.ect deter*ines the *apping !etween e"uation nu*!ers and degrees8of8

freedo* 88 how degrees8of8freedo* are nu*!ered,

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S$ste* co**and

#his co**and is used to construct the ;inearSOE

and ;inearSol4er o!.ects to store and sol4e the s$ste*

 of e"uations in the anal$sis

%nal$sis

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#est co**and

(ertain Solution %lgorith* o!.ects re"uire a (on4ergence #est o!.ect to

deter*ine if con4ergence has !een achie4ed at the end of an iteration step

%nal$sis

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%lgorith* co**and

#his co**and is used to construct a Solution %lgorith* o!.ect- which

deter*ines the se"uence of steps ta+en to sol4e the non8linear e"uation

%nal$sis

%nal$sis

%nal$sis

Etras

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'sing OpenSees in Batch Mode

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(alling OpenSees fro* a *atla! script

L in4o+e Matla!

OpenSees opsScript,tcl

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Parallel processing using OpenSeesSp

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Sensiti4it$- Delia!ilit$ and Opti*i&ation %nal$sis

http:opensees,!er+ele$,eduwi+iinde,phpSensiti4it$%nal$sis

http:opensees,!er+ele$,eduOpenSeeswor+shopsOpenSees)a$s2011B5MS,pdf 

http: .aguar,ucsd,eduOpenSees,ht*l

OpenSees Desource

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Message Board

http:opensees,!er+ele$,educo**unit$inde,php

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etting Started Manual

http:opensees,!er+ele$,eduwi+iinde,phpettingStarted

(o**and Manual

http:opensees,!er+ele$,eduwi+iinde,php(o**andManual

'ser Ea*ples

http:opensees,!er+ele$,eduwi+iinde,phpEa*ples

OpenSees or+shops)a$s

http:opensees,!er+ele$,eduwi+iinde,phpOpenSees)a$s2011

(onclusion

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OpenSees is a powerful tool for perfor*ing FE anal$sis

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It NEE)S contri!utions fro* others to grow

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OpenSees ;IJE %NC si*ulation tool re"uires the user to

understand the theor$ and li*itations

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OpenSees 3if features are full$ utili&ed will allow $ou to

generate *odels faster and *ore accuratel$ than $ou could

with a 'I and will allow $ou to o!tain infor*ation on the

'ncertaint$ using parallel co*puting resources that is the

do*inant co*puter architecture a4aila!le toda$,

 Notes

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OpenSees is pri*aril$ a research tool at this ti*e- !ut fairl$

sta!le and is used in professional practice

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%s with an$ nonlinear anal$sis- it re"uires careful

consideration of *odel and interpretation of results

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It is under continual de4elop*ent !$ students- facult$ and

other researchers

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'ser interface de4elop*ent lags !ehind co*putational

technolog$

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It is not !ullet8proof 

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 %n in4est*ent of ti*e and learning is re"uired

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#he OpenSees

open-source community

 re"uires contri!utions

%s+ these "uestion fro* $ourself !efore *odeling

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)ata: eo*etr$ and *aterial properties

e,g,- set span 100 node 1 span 0

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hat +ind of Material Model are $ou going to use

G

e,g,- elastic- Steel01- (oncrete01- 

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hat +ind of ele*ents are $ou going to useG

e,g,- truss- &ero;ength- dispBea*(olu*n- forceBea*(olu*n -

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hat t$pe of constraintsG

e,g,- fi- e"ual)OF- 

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hat +ind of loads or ecitationG

e,g,- pattern

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hat +ind of anal$sis are $ou going to perfor*G

e,g,- anal$sis Static

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hat +ind of response do $ou want to *onitorrecordG

Building Model 8 eo*etr$

Building Model

1

2

&

'

1(

1)

(

node $nodeTag (ndm $coords)

node $nodeTag $xcor $ycor 

Building Model 8 (onstraints

S (single point constraint)

 (multiple points constraint)

" #inge connection (beteen truss elements and gravity column nodes)

Building Model 8 Materials

Building Model 8 sections

Building Model 8 sections

" section properties (%&S' manual)

" section properties (%&S' manual)

  

Building Model 8 #ransfor*ation

Building Model 8 #ransfor*ation

" eometric *onlinearity

Building Model 8 Ele*ents

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 !ea*ithinges ele*ent o!.ect is !ased on the non8iterati4e 3or iterati4e flei!ilit$ for*ulation- and

considers plasticit$ to !e concentrated o4er specified hinge lengths at the ele*ent ends,

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 Note- the !ea*ithinges ele*ent locali&e plastic hinging at the ele*ent ends onl$,

#his t$pe of ele*ent di4ides the ele*ent in three parts:

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two hinges at the

ends-•

and a linear8elastic region in the *iddle,

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#he hinges are defined !$ assigning to each a pre4iousl$8defined section, #he length of the each hinge

Building Model @ Bea*ithinges Ele*ent

&ntegration points

#he !ea*ithinges ele*ent used here has four elastic sections and two fi!er

section at the end, #herefore for output in specif$ing secNu*:

secNu*K1: hinge at node i

secNu*K: hinge at node .

Decorders

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 Nodes:

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Ele*ents:

'se: 'se eit to finish and

wipe !efore running the

net one,

Pusho4er %nal$sis

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Pattern

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)isplace*ent (ontrolIntergrator 

;oad (ontrolIntergrator 

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%dapti4e Pusho4erG