P
E
E
R
Van Nuys Testbed Simulation
Laura N. Lowes - University of Washington
#setAnalysisParameters.tcl
#setAnalysisParameters.tcl
#-----------------------------------------------------------
#-----------------------------------------------------------
#PEER VanNuys Testbed Project
#PEER VanNuys Testbed Project
#-----------------------------------------------------------
#-----------------------------------------------------------
#script to define analysis parameters including element, section
andtomaterial
models parameters including element, section and material models
#script
define analysis
# ------------------------------------------------------------------------------------------------------------------------------------------begin
setAnalysisParameters
# ------------------------------------------------------------------------------------------------------------------------------------------begin
setAnalysisParameters
source $PATH/units.tcl
source $PATH/units.tcl
#MODEL
#MODEL
# model type 2D or 3D
# model type 2D or 3D
set 2Dvs3DModel "2D";
set 2Dvs3DModel "2D";
#ELEMENTS
#ELEMENTS
#Element Types
#Element Types
set ColumnElementType
"fiber-hinge";
# options: "elastic", "elasticEffStiff","lumped-plasticity", "fiber-hinge", "fiber", #"displacement-based"
set ColumnElementType
"fiber-hinge";
# options: "elastic", "elasticEffStiff","lumpedset BeamElementType
"fiber-hinge";
# options: "elastic", "elasticEffStiff","lumped-plasticity", "fiber-hinge", "fiber", #"displacement-based"
plasticity", "fiber-hinge", "fiber", #"displacement-based"
#IF elements are "displacement-based" - set number of elements to use along column / beam length
set BeamElementType
"fiber-hinge";
# options: "elastic", "elasticEffStiff","lumpedset NumColElements 1
plasticity", "fiber-hinge", "fiber", #"displacement-based"
set NumBeamElements 1
#IF elements are "displacement-based" - set number of elements to use along column / beam length
#IF elements are "fiber" or "displacement-based"- set Number
Integration Pointsto
setofNumColElements
1 use along length
set NumColIntPts 5
set NumBeamElements 1
set NumBeamIntPts 4
#IF elements are "fiber" or "displacement-based"- set Number of Integration Pointsto use along length
set ElementIter "yes"; #forces iteration within the element to set
satisfy
element equilibrium
NumColIntPts
5
set NumElementIter 20; #number of iterations within the element
set NumBeamIntPts 4
set tol 1e-12; #tolerance for element convergence
set ElementIter "yes"; #forces iteration within the element to satisfy element equilibrium
#IF "lumped-plasticity" or "fiber-hinge" - set stiffness factors for
beam section
set elastic
NumElementIter
20; between
#number hinges
of iterations within the element
#IF "elasticEffStiff" - set effective stiffness factors for beams,set
columns,
slab#tolerance for element convergence
tol 1e-12;
set BeamStiffnessReductionFactorFlex 0.5;
#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.
Deliverables
Original Schedule
(11702)
Deliverables
Revised Schedule (52102)
1/28/02
2D model – Gen. I
as needed by PEER researchers
5/31/02
2D model - Gen. II:
basic model &
parameterized model
5/31/02
2D model – Gen. III:
new request
includes shear-failure
springs, reduced lap-splice
capacity, multiple
representations of joint
deformation
6/15/02
new request
version control of
models (CVS)
8/1/02
10/1/02
3D model – Gen. IV:
8/1/02
9/1/02
Soil/foundation interaction
9/1/02

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, x = 3%
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
source setFrameGeometry.tcl
source setNodalMass.tcl
- define parameters for this particular analysis
- write data structure defining frame geometry
(story height, bay width, etc.)
- write data structure defining frame member geometry
(column/beam/slab prop.)
- write data structure defining material properties (each
column/beam/slab has concrete & steel material properties
- write data structure defining elements elastic section properties
(all elements have elastic properties - Torsional stiff.)
- nodal / distributed mass for dynamic analysis
source
source
source
source
source
-
source setFrameMemberSectionProperties.tcl
source setMaterialProperties.tcl
source setElasticElementProperties.tcl
defineStructuralMaterials.tcl
defineSections.tcl
defineNodes.tcl
defineElements.tcl
defineBoundaryConditions.tcl
source analyze.tcl
execute OpenSees
execute OpenSees
execute OpenSees
execute OpenSees
execute OpenSees
conditions
- run analysis
command
command
command
command
command
to
to
to
to
to
generate required materials
generate required sections
generate required nodes
generate required elements
establish required boundary
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 dimension
set MaxFiberDim
[expr 0.5*$in];
#MATERIALS
set 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, 8
set Columns
1;
#Output is disp., vel. & accel. at a single column
Basic Model: Push-Over Analysis
Base Shear (kips)
700
600
500
400
300
200
100
0
00
5
10
15
20
Roof Displacement (in.)
25 0
5
10
15
20
Roof Displacement (in.)
25
Basic Model – Simulated Response – NR vnuy
Ground Acceleration – Northridge Eq. - Building Instrumentation
0
5
10
tim e (seconds)
15
20
Basic Model – Simulated Response – NR vnuy
Ground Acceleration – Northridge Eq. - Building Instrumentation
0
5
10
tim e (seconds)
15
20
Basic Model – Response to Dynamic Loading
Deformation Distribution at Maximum Roof Displacement
8
7
Story
6
5
Hazard Level:
10% in 50 yr.
4
3
*
2
NR.cnpk
SF.vnuy
NR.vnuy
SF.466
1
0
5
10
15
Displacement (in.)
20
25
Results – Parameterized Model
1100
FEMA 356
load distribution
1000
Base Shear (kips)
900
700
800
600
500
400
300
nonlinearBeamColumn
200
100
0
0
5
10
15
20
Roof Displacement (in.)
25
30
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.)