Van Nuys Testbed Simulation Laura N. Lowes University of Washington

1
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 sou
rce PATH/units.tcl MODEL model type 2D or
3D set 2Dvs3DModel "2D" ELEMENTS Element
Types set ColumnElementType "fiber-hinge"
options "elastic", "elasticEffStiff","lumped-plas
ticity", "fiber-hinge", "fiber",
"displacement-based" set BeamElementType
"fiber-hinge" options "elastic",
"elasticEffStiff","lumped-plasticity",
"fiber-hinge", "fiber", "displacement-based" I
F 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 sou
rce PATH/units.tcl MODEL model type 2D or
3D set 2Dvs3DModel "2D" ELEMENTS Element
Types set ColumnElementType "fiber-hinge"
options "elastic", "elasticEffStiff","lumped-plas
ticity", "fiber-hinge", "fiber",
"displacement-based" set BeamElementType
"fiber-hinge" options "elastic",
"elasticEffStiff","lumped-plasticity",
"fiber-hinge", "fiber", "displacement-based" I
F 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
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The Objectives

• Develop a model of the Van Nuys building within
  OpenSees that can be used to
• Simulate building response under variable levels
  of earthquake loading results support loss
  estimation.
• Determine the impact of epistemic uncertainty on
  predicted response results support development
  of the PEER methodology.
• Support development of new element models within
  OpenSees.
• Predict the post-peak response of the Van Nuys
  building.

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Deliverables
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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)

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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

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What is the form of the model?

• VanNuys.tcl
• model BasicBuilder -ndm 3 -ndf 6
• source setAnalysisParameters.tcl - define
  parameters for this particular analysis
• source 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 nodes
• source defineElements.tcl - execute OpenSees
  command to generate required elements
• source defineBoundaryConditions.tcl - execute
  OpenSees command to establish required boundary
  conditions

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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 0.5in
• 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

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Basic Model Push-Over Analysis
Roof Displacement (in.)
Roof Displacement (in.)
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Basic Model Simulated Response NR vnuy
Ground Acceleration Northridge Eq. - Building
Instrumentation
Roof Acceleration (in./sec.)
Acceleration (in./sec.)
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Basic Model Simulated Response NR vnuy
Ground Acceleration Northridge Eq. - Building
Instrumentation
Roof Displacement (in.)
Displacement (in.)
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Basic Model Response to Dynamic Loading
Hazard Level 10 in 50 yr.
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Results Parameterized Model
FEMA 356 load distribution
Roof Displacement (in.)
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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

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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.)