PPEEEERR

Van Nuys Testbed Simulation Laura N. Lowes - University of Washington

#setAnalysisParameters.tcl

#-----------------------------------------------------------

#PEER VanNuys Testbed Project

#-----------------------------------------------------------

#script to define analysis parameters including element, section and material models

# ------------------------------------------------------------------------------------------------------------------------------------------begin setAnalysisParameters

source $PATH/units.tcl

#MODEL

# model type 2D or 3D

set 2Dvs3DModel "2D";

#ELEMENTS

#Element Types

set ColumnElementType "fiber-hinge"; # options: "elastic", "elasticEffStiff","lumped-plasticity", "fiber-hinge", "fiber", #"displacement-based"

set BeamElementType "fiber-hinge"; # options: "elastic", "elasticEffStiff","lumped-plasticity", "fiber-hinge", "fiber", #"displacement-based"

#IF elements are "displacement-based" - set number of elements to use along column / beam length

set NumColElements 1

set NumBeamElements 1

#IF elements are "fiber" or "displacement-based"- set Number of Integration Pointsto use along length

set NumColIntPts 5

set NumBeamIntPts 4

set ElementIter "yes"; #forces iteration within the element to satisfy element equilibrium

set NumElementIter 20; #number of iterations within the element

set tol 1e-12; #tolerance for element convergence

#IF "lumped-plasticity" or "fiber-hinge" - set stiffness factors for elastic beam section between hinges

#IF "elasticEffStiff" - set effective stiffness factors for beams, columns, slab

set BeamStiffnessReductionFactorFlex 0.5;

#setAnalysisParameters.tcl

#-----------------------------------------------------------

#PEER VanNuys Testbed Project

#-----------------------------------------------------------

#script to define analysis parameters including element, section and material models

# ------------------------------------------------------------------------------------------------------------------------------------------begin setAnalysisParameters

source $PATH/units.tcl

#MODEL

# model type 2D or 3D

set 2Dvs3DModel "2D";

#ELEMENTS

#Element Types

set ColumnElementType "fiber-hinge"; # options: "elastic", "elasticEffStiff","lumped-plasticity", "fiber-hinge", "fiber", #"displacement-based"

set BeamElementType "fiber-hinge"; # options: "elastic", "elasticEffStiff","lumped-plasticity", "fiber-hinge", "fiber", #"displacement-based"

#IF elements are "displacement-based" - set number of elements to use along column / beam length

set NumColElements 1

set NumBeamElements 1

#IF elements are "fiber" or "displacement-based"- set Number of Integration Pointsto use along length

set NumColIntPts 5

set NumBeamIntPts 4

set ElementIter "yes"; #forces iteration within the element to satisfy element equilibrium

set NumElementIter 20; #number of iterations within the element

set tol 1e-12; #tolerance for element convergence

#IF "lumped-plasticity" or "fiber-hinge" - set stiffness factors for elastic beam section between hinges

#IF "elasticEffStiff" - set effective stiffness factors for beams, columns, slab

set BeamStiffnessReductionFactorFlex 0.5;

The Objectives

Develop a model of the Van Nuys building within OpenSees that can be used to

1. Simulate building response under variable levels of earthquake loading – results support loss estimation.

2. Determine the impact of epistemic uncertainty on predicted response – results support development of the PEER methodology.

3. Support development of new element models within OpenSees.

4. Predict the post-peak response of the Van Nuys building.

DeliverablesOriginal Schedule

(11702)Deliverables

Revised Schedule (52102)

1/28/02 2D model – Gen. Ias needed by PEER

researchers

5/31/022D model - Gen. II:

basic model & parameterized model

5/31/02

new request

2D model – Gen. III:includes shear-failure springs, reduced lap-

splice capacity, multiple

representations of joint deformation

6/15/02

new requestversion control of

models (CVS)8/1/02

10/1/02 3D model – Gen. IV: 8/1/02

9/1/02Soil/foundation

interaction9/1/02

Gen. II Model

• Basic model:– Comparable to SAP model developed by Degenkolb– 2D model: one exterior & one interior frame (3D with slaving) – Modeling assumptions:

• BeamWithHinges element model, rigid joints, • Concrete & steel material response per FEMA 356• Effective stiffnesses used to generate an initial period of 0.89 sec• No gravity load representation (waiting on new element that

includes distributed loading)• No representation of shear failure for columns• Inadequate representation of splice failure for columns - reduced

strength not ductility capacity)

Gen. II & III Models

• Parameterized model:– For use is assessing the impact of epistemic uncertainty

– 2D model: one exterior & one interior frame

– Modeling parameters:• Element type: BeamWithHinges / NonlinearBeamcolumn /

EffectiveStiffness / DisplacementBased

• Column failure mechanisms: Splice failure / shear failure

• BC Joints: Rigid / center-line dimensions / strength & stiffness degrading

• Material models: Variable material models / variable material data (stiffness & strain capacity)

• Level of discretization: Displacement-based elements / sections

• Effective stiffness values: BeamWithHinges / EffectiveStiffness model

• Damping

What is the form of the model?

VanNuys.tcl

model BasicBuilder -ndm 3 -ndf 6

source setAnalysisParameters.tcl - define parameters for this particular analysissource setFrameGeometry.tcl - write data structure defining frame geometry

(story height, bay width, etc.)source setFrameMemberSectionProperties.tcl - write data structure defining frame member geometry

(column/beam/slab prop.) source setMaterialProperties.tcl - write data structure defining material properties (each

column/beam/slab has concrete & steel material properties

source setElasticElementProperties.tcl - write data structure defining elements elastic section properties (all elements have elastic properties - Torsional stiff.)

source setNodalMass.tcl - nodal / distributed mass for dynamic analysis

source defineStructuralMaterials.tcl - execute OpenSees command to generate required materials

source defineSections.tcl - execute OpenSees command to generate required sections

source defineNodes.tcl - execute OpenSees command to generate required nodessource defineElements.tcl - execute OpenSees command to generate required

elementssource defineBoundaryConditions.tcl - execute OpenSees command to establish required

boundary conditions

source analyze.tcl - run analysis

setAnalysisParameters.tcl

setAnalysisParameters.tcl#MODEL#Model Type – options: “2D”, “3D”set 2Dvs3DModel "2D";#ELEMENTS#Element Types - options: "elastic", "elasticEffStiff", "lumped-plasticity", "fiber-hinge", "fiber", “disp”set ColumnElementType "fiber-hinge";set BeamElementType "fiber-hinge"; #SECTIONS#IF fiber section - Define maximum fiber dimensionset MaxFiberDim [expr 0.5*$in];#MATERIALSset ConcreteMaterialType "Concrete01"; # options: “Concrete01",“Concrete02", …set SteelMaterialType "Steel02"; # options: “Steel01”, “Steel02” #ANALYSIS#set AnalysisType - options: "Gravity", "Eigen", "Dynamic", "Pushover"set AnalysisType "Pushover“;#OUTPUT #options Columns 1, 4, 8set Columns 1; #Output is disp., vel. & accel. at a single column

Basic Model: Push-Over Analysis

Roof Displacement (in.) Roof Displacement (in.)

0

700

0 5 10 15 20 25 0 5 10 15 20 25

500

400

300

200

100

600

0

Bas

e S

hear

(ki

ps)

Basic Model – Simulated Response – NR vnuy

Ground Acceleration – Northridge Eq. - Building Instrumentation

Acc

eler

atio

n (

in./s

ec.)

Roof Acceleration (in./sec.)

Basic Model – Simulated Response – NR vnuy

Ground Acceleration – Northridge Eq. - Building Instrumentation

Dis

pla

cem

ent

(in

. )

Roof Displacement (in.)

Basic Model – Response to Dynamic Loading

NR.cnpk

SF.vnuy

NR.vnuy

SF.466

*

Deformation Distribution at Maximum Roof Displacement

8

7

6

5

4

3

2

Sto

ry

10 5 10 15 20 25

Displacement (in.)

Hazard Level:10% in 50 yr.

Results – Parameterized Model

700

500

400

300

200

100

600

0

800

900

1000

1100

0 5 10 15 20 25 30

Bas

e S

hear

(ki

ps)

nonlinearBeamColumn

FEMA 356 load distribution

Roof Displacement (in.)

Distribution & Documentation

• Web-based distribution • Accessible from UW website:

– Data from numerical simulation: Gen II – basic model

– Documentation of modeling decisions

– Tcl script defining Van Nuys building

• To be developed - version control for models

Current Tasks

• Issue of model period– predicted period ~0.9 seconds, observed is 1.5

sec.– May need to run model through San Fernando

record to pre-damage the building

• Gravity loading – this determines point of yielding

• Shear / splice failure• Distrubiton of results (story drift & acc.)