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Pivoting Fuse System

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					NEESR Controlled Rocking of
   Steel Braced Frames
     Summary Presentation
         April 2006
Pivoting Fuse Braced Frames
                                            D                   Force




                                        H


                    “Structural Fuse”




                                                A   B    A
All the inelasticity and damage is concentrated in structural fuse and
     braced frame remains elastic (i.e. no yielding or buckling).
    Pivoting Fuse Braced Frames
                        2A D    •   Behavior similar to EBF
                     g            systems
                        B H
      D                              – Yields at low drifts (≈0.25%)
                                     – High shear strain demands in
                                       fuse (≈8%)
                                     – Strength, stiffness, & ductility
                                       based on fuse behavior
                                •   Localized damage & easily
H                                   replaceable components
                                •   Capacity designed brace frame
                                    (EBF design approach)
                                •   Potential Problems
                                     – Residual drifts, no restoring
                                       force
                                     – Shear strain capacity of fuse
          A    B    A
Ex: IDR = 1%, A/B = 4, g = 8%
                             Pivoting Fuse Braced Frames
                                   Yielding of Fuse
                  2500
                                                          PT = 2000kN
                                                                                      D                          3F
                              Story
                             Story 23
                  2000

                                                                                                                2F
Base Shear (kN)




                  1500

                                                                                  H
                  1000                                                                                          F
                                                   Elastic Unloading

                   500
                                                         3-story Frame
                                                 3 mm. thick steel plate
                     0
                         0    0.005     0.01   0.015   0.02   0.025        0.03
                                               RDR
                                                                                          A   B     A
                     Residual or permanent
                         displacement

                                                       Residual displacements after an EQ will ultimately be a problem.
                 Pivoting Fuse System
                   with Backup MRF
                                             • Elastic restoring force
                                                          – Reduce damage in
Figure 1a
                                                            fuse
                                                          – Reduce residual
                                                            deformations
                     deck/slab
                                             • Provides redundancy
                                 Figure 1a

              Framing Plan
                                                                          Both
                                             Base Shear                   Pivoting Fuse


                                                                          MRF
            Framing Elevation



Moment Resisting Frames                                         Drift
“Rocking” Braced Frames
        Force            Force




        Dead + Live load                No energy
        provides resistance             dissipation



                                           Displacement
                                      No Permanent
                                      Displacement

        Lifts off of ground



                 We would like to control rocking and
                 also provide some dissipation energy
           Controlled Rocking Brace Frames
                                                           Yielding of
                                                           Structural Fuse
                       Structural Fuse


                                         Post-tensioning
                                         (PT) Tendons




                                     PT Cables & Braces
                                       remain elastic




Steel Braced
Frame




                                                    Could potentially
               A   B     A                          employ additional
                                                    fuse at base of column
      Controlled Rocking Brace Frames
      A D
 g    
      B H
                                • Self-centering system

                                • Localized damage, easily
                                  replaceable fuses

                                • Global strength a function of PT
                                  force plus fuse strength

                                • Ductility based on fuse
                                   – Half the shear strain demand as
                                     compared to pivoting fuse system

                                • PT remains elastic
                                   – For buildings < 6 stories, PT must
                                     be looped under building
  A       B      A
Ex: IDR = 1%, A/B = 4, g = 4%
            Controlled Rocking Brace Frames




                                         Overturning Moment
                                                                                   Fuse Resistance
                                                                                   Vp(A+B)
                      Vp



                                                                        PT Resistance
                                                                        2PT(A)

                                                                                                  Drift


                                      Resisting Overturning Moment
                                           (2PT)*A + Vp*(A+B)

                                                              Self Centering Criterion   (Elastic-PP Fuse)
PT           PT       PT       PT                                2PT(A) > Vp(A+B)

                                                              Dual Frame Rocking
                                                                                         avoids
        A         B        A                                       PT > Vp/2
     Vp = Total fuse shear strength
                       Parallel System
                                 Uplift + Fuse
                                                                    Idealized elastic-perfectly




                         Force
                                                                    plastic (EPP) fuse


                                            Fuse Strength     Effective Fuse
                                                              Stiffness, Keff,Fuse

                                                            Drift




  Fuse System Only

                                                                       Uplift elongates PT &
                        Force




                                                                        increases PT Force
                                                                      DPT = EAPT*Duplift/LPT


                                                            PT Strength

                                 Frame Stiffness, kframe

PT/Brace System Only                                        Drift
                   Pretension/Brace System                                                                Fuse System




                                                                         Base Shear
                                         d    c                                                       b                           c
Base Shear

                                 e
             a,f   b
                                                                                                            Fuse Strength      Eff. Fuse
                                                                                                                               Stiffness
                           PT Strength                                                        a                        d
              g
                                                                                                                              Drift

               Frame Stiffness
                                                                            g                 f                  e

                                             Drift



                                                                                                  b                           c




                                                            Base Shear
Origin-a – frame strain + small
distortions in fuse
a – frame lift off, elongation of PT                                                                      2x Fuse
                                                                                                          Strength     d
b – fuse yield (+)                                                                        a
c – load reversal
d – zero force in fuse                                  PT
e – fuse yield (-)                                   Strength                                                    e
f – frame contact                                                                     f
f-g – frame relaxation
                                                                                                  PT – Fuse Strength
g – strain energy left in frame and fuse,                                             g
small residual displacement                                                                                                 Drift
                                                                                          Combined System
     Sizing the Post-Tensioning Tendons

                                              For building shorter than 6 stories, the PT
                                              cables have to be looped under the building
                                  H
                                              to have enough strain capacity to
                                              accommodate uplift.




           A
Two design criteria for the PT tendons:
•   Required PT Force (from desired PT:Fuse ratio):
                        PT
           Area PT              ;  allow  0.4GUTS  0.4(1860 MPa )  744 MPa
                        allow
(2) PT Stress at maximum toe uplift:                                                        Design
                                                                                            Variable
                              Duplift E                                 Duplift
           max   allow                ;  max  0.85GUTS; (e.g.)               2.5%
                                 LPT                                      A
   Post-tensioning Stress-Strain Behavior

                                  eGUTS = 4%
               2000
                                                                              GUTS=1860MPa
               1800

               1600                                                     0.85GUTS=1581MPa
Stress (MPa)




               1400
                                                                                                  Minimum uplift
                                  7-Wire Strand                                                   strain capacity
               1200
                                                                                                    prior to yield
               1000

                800                                                      0.4GUTS=744MPa
                600

                400                                                                                Post-tension
                                                                                                  up to 0.4GUTS
                                              Deformed Reinforcing Bar
                200

                  0
                      0   1   2   3   4   5   6   7   8   9   10   11    12   13   14   15   16

                                                  Strain %
Structural Fuse Options
                                 HPFRCC Panels
 • High Performance Fiber
   Reinf. Concrete (ECC)
       – Distributed cracking
       – Good energy dissipation
       – No transverse reinforcement


                                                                                 Applied Load (kN)

                                                             Actuator                     60
                     HPFRCC
                      mix 1
                                                                        HPFRCC
                                                                         Panel            40
                              Reinforced   HPFRCC
                               concrete     mix 2
                                                                                          20


                                                                                            0
                                                    -2.50%              -1.50%     -0.50%         0.50%         1.50%         2.50%
                                                                                                                            Drift (%)
            Plain                                                                               -20
          concrete
                                                                                                          HPFRCC-1
                                                                                                -40       HPFRCC-2
                                                                                                          Reinf. Concrete

                                                                                                -60
Kesner et al. 2005
                     HPFRCC Panels


 Height-width: 2-1




Kesner et al. 2005
                     HPFRCC Panels


                                            Panel at
                                            0.5% drift
 Height-width: 2-1




                                     Ultimate failure:
                                     splitting at
                                     connection.




Kesner et al. 2005
                 HPFRCC Panels
                     Butterfly Panels

                     Height to width ratio of
                     links close to 1 – likely
                     a combination of shear
                     and flexure behavior.

                     Could adjust A/B ratio
                     to enforce more flexural
                     yielding.




                     Slit Tapered Panels

                     Height to width ratio of
                     links approximately 2-1.

                     Region detailed to carry
                     shear after flexural
                     hinging
                                                 A   B   A
Offset helps distribute stresses near
connection, hopefully postponing splitting.
               HPFRCC Coupling Beams




                                          1.5% Drift




                                          3.0% Drift



                                  Localization
Canbolat et al. 2005              occurred at 4% drift
               HPFRCC Coupling Beams




Hyun-Do et al. 2005
               HPFRCC Coupling Beams




Hyun-Do et al. 2005
             HPFRCC Coupling Beams
                            Split Panel


                                  Headed Reinforcement?



                              Hopefully avoid/postpone
                              splitting at connection.


Region of inelastic deformation



                            Full Panel

                            Reinforcement pattern?




                                                          A   B   A
        Steel Shear Wall with Slits




- Can adjust strength and stiffness
with different slit configurations

- Among the largest ductilities of all
possible fuses

- Previous tests applicable to our
scale
                                         Hitaka 2003
             Steel Shear Wall with Slits
Panel Dimensions:
800x800x4.5mm




             Post-peak strength deterioration begins at 5% drift and is a result
             of transverse displacements in the links.
                                                                                   Hitaka 2003
Steel Shear Wall with Slits




   Bolted connection to
         steel columns


                          A   B   A
       Reduced Web Section Beams




                          Web buckling occurs at 1-
                          1.25% drift resulting in 30%
                          drop in strength.

                          Beyond the point of
                          buckling, lateral resistance
                          remains stable out to 6%
                          drift.

                          After 6% drift, web posts
                          begin to fracture. At larger
                          drifts the flanges go into
                          tension.
Aschheim 2002
       Reduced Web Section Beams




Aschheim 2002
Reduced Web Section Beams
     Welded to steel plate




   Bolted to steel column




                             A   B   A
                    Steel Shear Panel

• Stiffened: postpones buckling
• Unstiffened: allows buckling
• May provide too much strength
  for lower rise buildings




                                        Driver et. al 1997
                  Composite Panel
• Steel + HPFRCC materials
• Prevents buckling
• Added strength from HRFRCC
  panel at larger drifts
• May be too strong for lower
  rise buildings




                                    Zhao & Astaneh-Asl 2004
                    Low Yield Steel Panels

  • Less controlled by buckling
  • Higher toughness/ductility
  • Large strain hardening
       – is this good or bad?




Nakashima 1995
      Delayed Yielding of Panels up Height




                                                  Taper wall or      Increase link height
                                                Taper within Panel

                                                   Dp = f (L3)           Dp = f (1/h)


                                                      Base
                                                      Shear
Tapered Wall/Braced Frame or Tapered Panel
- Delays yielding up the height of structure                            More gradual yielding
- May limit damage to lower panels in smaller EQ
- Global response is more gradually nonlinear
                                                                                  Drift
Additional Issues for Taller Frames


                  Demand in fuse
                  increases up height   Tapered fuse?




                  • Demand in fuse a function of
                    rocking + frame flexibility

                  • Braced frame is much more
                    flexible in taller buildings

                  • Impact of higher modes on
                    rocking?

                  • Is post tensioning necessary
                    with increased gravity loads?
 General Building Integration Issues


                                      Slab on Steel Deck




                                      Slab on Steel Deck




                                                                                  Curtain Wall
Considerations:
• Does slab connect to spandrel beam (composite action) or is it isolated from slab?
• If isolated from slab, then how are the loads transferred into the frame?
• If connected to slab, how can we accommodate expected deformation and damage in the
slab when rocking/uplift occurs?
• How are the curtain walls anchored or isolated?
   Possible HPFRCC Application in Slab?


                                 Slab on Steel Deck


If the slab is connected
  to the rocking frame
                                                      HPFRCC
                                 Slab on Steel Deck
                                                      slab infill


                                                              Curtain Wall




    Slab Deformation


              Regular Concrete                               Maximizes energy
                                        HPFRCC
                                                             dissipation of slab
OpenSees Modeling

Static and Cyclic Analyses
                      OpenSees Model
Nonlinear Truss
  Members


                          Elastic Truss
                            Members




                          EPP Post-
                          Tensioning
                           Tendons




                           Uplift
                           Spring




          A       B   A                   A   B   A
                                                         Static Pushover Response
                  4000                                                                                             160
                                   PT = 1500kN                                                                                    PT = 1500kN
                  3500                                                                                             140
                                                                        Yielding of PT
                                                                                                                   120
                  3000

                                                     Computed Base Shear                                           100
                                                                                                                                Maximum PT Uplift
                  2500
Base Shear (kN)




                                                     2525kN




                                                                                                     Uplift (mm)
                               Story 3
                                                                                                                    80
                  2000        Story 2
                                                                                                                    60
                                                                                                                                                                           Yielding of PT
                  1500
                                                                                                                    40

                  1000
                                                                                                                    20

                   500                                                      3-story Frame                                     Story 3
                                                                                                                     0       Story 2
                                                                    3 mm. thick steel plate
                      0                                                                                            -20
                          0     0.005    0.01    0.015   0.02   0.025     0.03    0.035       0.04                       0     0.005    0.01    0.015     0.02     0.025     0.03   0.035   0.04
                                                         RDR                                                                                            Roof Drift

 3F


              2F
                                                                • Computed Overturning Moment: 2PT + Vp,fuse(A+B)
                                                                • Elastic perfectly plastic fuse
                  F                                             • PT looped under building: PT length = 2*(Building Height)
                     Individual System Behavior
                  3500
                                      PT = 1500kN
                                                     PT/Brace & Fuse           PT MAX

                  3000                                                          Yielding of PT



                  2500
                                                                           PT/Brace Only
Base Shear (kN)




                             Uplift                                        No Fuse
                  2000


                  1500                              Brace/Fuse Only
                                 Uplift             No PT
                                                                                  EPP Fuse
                                                                                   3-story Frame
                  1000                                                             Hardening = 0
                                                                       PostCap Softening = -0.02
                                                                                Strength Det. = 0
                   500                  Degrading Fuse                    Unloading Stiff Det. = 0
                                                                        Accelerated Stiff. Det. = 0
                                                                       PostCap Strength Det. = 0
                     0
                         0   0.005         0.01     0.015   0.02      0.025      0.03     0.035       0.04
                                                            RDR
                  4000                                                                                           4000

                             (2PT*A) / (Vp (A+B)) = 1.2
                             Hardening = 0.1
                             PostCap Softening = -0.02
                                                                                                                             Hardening = /
                                                                                                                            (2PT*A) 0.1(Vp-0.02
                                                                                                                             PostCap Softening =
                                                                                                                                                 (A+B)) = 1.4
                  3000                                                                                           3000
                             Strength Det. = 0                                                                              Strength Det. = 0
                             Unloading Stiff Det. = 0                                                                       Unloading Stiff Det. = 0
                  2000       Accelerated Stiff. Det. = 0                                                         2000       Accelerated Stiff. Det. = 0
                             PostCap Strength Det. = 0                                                                      PostCap Strength Det. = 0

                  1000                                                                                           1000
Base Shear (kN)




                                                                                               Base Shear (kN)
                      0                                                                                              0


                  -1000                                                                                          -1000


                  -2000                                                                                          -2000


                  -3000                                                                                          -3000
                                                                        3-story Frame                                                                                  3-story Frame
                  -4000                                                                                          -4000
                     -0.06        -0.04        -0.02        0    0.02      0.04         0.06                        -0.06        -0.04        -0.02        0    0.02      0.04         0.06
                                                           RDR                                                                                            RDR
                  5000                                                                                           6000

                  4000       (2PT*A) / (Vp (A+B)) = 2.0
                             Hardening = 0.1
                             PostCap Softening = -0.02
                                                                                                                            (2PT*A) / (Vp (A+B)) = 3.0
                                                                                                                            Hardening = 0.1
                                                                                                                            PostCap Softening = -0.02
                             Strength Det. = 0                                                                   4000       Strength Det. = 0
                  3000       Unloading Stiff Det. = 0                                                                       Unloading Stiff Det. = 0
                             Accelerated Stiff. Det. = 0                                                                    Accelerated Stiff. Det. = 0
                  2000       PostCap Strength Det. = 0                                                                      PostCap Strength Det. = 0
                                                                                                                 2000
Base Shear (kN)




                  1000                                                                         Base Shear (kN)

                      0                                                                                              0

                  -1000
                                                                                                                 -2000
                  -2000

                  -3000
                                                                                                                 -4000
                  -4000
                                                                        3-story Frame                                                                                  3-story Frame
                  -5000                                                                                          -6000
                     -0.06        -0.04        -0.02        0    0.02      0.04         0.06                        -0.06        -0.04        -0.02        0    0.02      0.04         0.06
                                                           RDR                                                                                            RDR
                          Bilinear vs. Pinching Fuse
                  6000                                                                                               600



                  4000                                                                                               400



                  2000                                                                                               200
Base Shear (kN)




                                                                                                  Axial Force (kN)
                      0                                                                                                 0



                  -2000                                                                                              -200



                  -4000                                                                                              -400
                                                                         3-story Frame
                                                                 3 mm. thick steel plate
                  -6000                                                                                              -600
                     -0.06        -0.04        -0.02        0    0.02       0.04           0.06                        -0.05   -0.04   -0.03   -0.02   -0.01      0    0.01   0.02   0.03   0.04
                                                           RDR                                                                                           Link Strain

                  6000                                                                                               600
                             Hardening = 0
                             PostCap Softening = -0.02
                  4000       Strength Det. = 0                                                                       400
                             Unloading Stiff Det. = 0
                             Accelerated Stiff. Det. = 0
                             PostCap Strength Det. = 0
                  2000                                                                                               200
Base Shear (kN)




                                                                                                  Axial Force (kN)




                      0                                                                                                 0



                  -2000                                                                                              -200



                  -4000                                                                                              -400
                                                                         3-story Frame
                                                                 3 mm. thick steel plate
                  -6000                                                                                              -600
                     -0.06        -0.04        -0.02        0    0.02       0.04           0.06                        -0.05   -0.04   -0.03   -0.02   -0.01      0    0.01   0.02   0.03   0.04
                                                           RDR                                                                                           Link Strain
                                                     Differences in Restoring Force…
                                         5000                                                                                                      600
                                                    Hardening = 0
                                         4000       PostCap Softening = -0.02
                                                    Strength Det. = 0                                                                              400
                                                    Unloading Stiff Det. = 0
                                         3000
                                                                                               2*Fuse
Bilinear Fuse



                                                    Accelerated Stiff. Det. = 0
                                                    PostCap Strength Det. = 0
                                         2000                                                                                                      200




                                                                                                                         Shear (kN)
                                                                                                                                                                                                 2*Fuse
                Base Shear (kN)




                                                                                                                         Axial Force (kN)
                                         1000
                                                                                                                                                      0
                                             0

                                         -1000                                                                                                     -200

                                         -2000
                                                                                                                                                   -400
                                         -3000                                                  3-story Frame
                                                                                        3 mm. thick steel plate
                                         -4000                                                                                                     -600
                                            -0.06        -0.04        -0.02        0    0.02        0.04          0.06                               -0.02   -0.015   -0.01   -0.005         0    0.005    0.01    0.015
                                                                                  RDR                                                                                             Link Strain
                                                                                                                                                                                   Strain
                                          4000                                                                                                     600
                                                    Hardening = 0
                                          3000      PostCap Softening = -0.02
                                                    Strength Det. = 0
                                                                                               <2*Fuse
Pinching Fuse




                                                                                                                                                   400
                                                    Unloading Stiff Det. = 0
                                          2000      Accelerated Stiff. Det. = 0
                                                    PostCap Strength Det. = 0

                                                                                                                                 Shear (kN)
                                                                                                                                                   200
                                          1000                                                                                                                                                   <2*Fuse
                       Base Shear (kN)




                                                                                                                                Axial Force (kN)


                                              0                                                                                                       0


                                         -1000
                                                                                                                                                   -200

                                         -2000

                                                                                                                                                   -400
                                         -3000                                                  3-story Frame
                                                                                        3 mm. thick steel plate
                                         -4000                                                                                                     -600
                                            -0.06         -0.04       -0.02        0    0.02       0.04           0.06                               -0.02   -0.015   -0.01   -0.005         0   0.005    0.01    0.015
                                                                                  RDR                                                                                             Link Strain
                                                                                                                                                                                   Strain
                                 Bilinear vs. Pinching Fuse
                  3000                                                                               2500
                                                                                                                Hardening = 0
                                                                                                     2000       PostCap Softening = -0.02
                  2000                                                                                          Strength Det. = 0
                                                                                                     1500       Unloading Stiff Det. = 0
                                                                                                                Accelerated Stiff. Det. = 0
                                                                                                     1000       PostCap Strength Det. = 0
                  1000
Base Shear (kN)




                                                                                   Base Shear (kN)
                                                                                                      500

                      0                                                                                  0
                                                           Not                                        -500                                          Restoring
                  -1000                                    Restoring                                 -1000

                                                                                                     -1500
                  -2000
                                                                                                     -2000
                                                            3-story Frame                                                                                  3-story Frame
                  -3000                                                                              -2500
                     -0.06    -0.04   -0.02    0    0.02       0.04         0.06                        -0.06        -0.04        -0.02        0    0.02      0.04         0.06
                                              RDR                                                                                             RDR



                                                    PT Strength = Fuse Strength
                                                       (2PT*A) / (Vp,fuse (A+B)) = 1.0
                          The hysteretic behavior of the fuse can impact the way we design the PT to fuse
                          strength ratio. A fuse with pinched behavior requires less restoring force to return
                          back to zero displacement, therefore this allows us to provide a stronger fuse than
                          if elastic perfectly plastic behavior is assumed.
                                                   Yielding of PT Tendons
                      workingStress = 0.4GUTS
                      max = 0.8GUTS
                      Lpt = 2*(Building Height) = 24000mm
                      Uplift Capacity = ecapacity*Lpt = 4%*Lpt = 960mm
                                                                                                                                              Uplift = 130mm
                  2500
                                                                            PT = max                        140                              RDR = 3.5%
                             Hardening = 0
                  2000       PostCap Softening = -0.02                                                       120
                             Strength Det. = 0
                                                                                                                   
                  1500       Unloading Stiff Det. = 0                                                                  max
                             Accelerated Stiff. Det. = 0                                                     100
                  1000       PostCap Strength Det. = 0
Base Shear (kN)




                   500                                                                                        80


                      0                                                                        Uplift (mm)    60

                   -500
                                                                                                              40
                  -1000
                                                                                                              20
                  -1500

                  -2000                                                                                        0
                                                                        3-story Frame
                  -2500                                                                                      -20
                     -0.06        -0.04        -0.02        0    0.02      0.04         0.06                       0         0.005   0.01   0.015     0.02     0.025   0.03   0.035   0.04
                                                           RDR                                                                                      Roof Drift
                                                Yielding the PT Tendons
                                                        further...
                  2500                                                                                       250
                                                                                                                                       Uplift = 200mm
                             Hardening = 0
                  2000       PostCap Softening = -0.02
                             Strength Det. = 0
                                                                                                                                       RDR = 5.5%
                  1500       Unloading Stiff Det. = 0                                                        200
                             Accelerated Stiff. Det. = 0
                  1000       PostCap Strength Det. = 0
Base Shear (kN)




                   500                                                                                       150




                                                                                               Uplift (mm)
                      0
                                                                                                                   
                                                                                                                       max
                   -500                                                                                      100

                  -1000

                  -1500                                                                                       50

                  -2000
                                                                        3-story Frame
                  -2500                                                                                        0
                     -0.06        -0.04        -0.02        0    0.02      0.04         0.06                       0         0.01   0.02     0.03       0.04   0.05   0.06
                                                           RDR                                                                             Roof Drift


                     By the time the PT cable reaches strains greater than 4%, the frame would have
                     experienced very large drifts (RDR = 24%). PT tendons continue to provide restoring
                     force until the effective working stress has dropped below the strength of the fuse.

                     Recall that this only impacts shorter buildings. In taller frames, PT yielding would
                     likely not occur.
                  2500                                                                                                                250
                             Hardening = 0
                  2000       PostCap Softening = -0.02                                                                                                           PT reaches 0.85GUTS
                             Strength Det. = 0
                  1500       Unloading Stiff Det. = 0                                                                                 200
                             Accelerated Stiff. Det. = 0
                  1000       PostCap Strength Det. = 0
Base Shear (kN)




                   500                                                                                                                150




                                                                                                                        Uplift (mm)
                      0                                                                                                                     
                                                                                                                                                max

                   -500                                                                                                               100

                  -1000

                  -1500                                                                                                                50

                  -2000
                                                                          3-story Frame
                  -2500                                                                                                                 0
                     -0.06        -0.04        -0.02        0      0.02      0.04                               0.06                        0             0.01       0.02       0.03       0.04   0.05   0.06
                                                           RDR                                                                                                                Roof Drift

                                                                                                      1.6
                                                                 0.85GUTS
                                                                                                      1.4


                                                                                                      1.2
                                                                                PT Stress (kN/mm 2)




                                                                                                       1


                                                                                                      0.8


                                                                                                      0.6
                                                                 0.3GUTS
                                                                                                      0.4                                                                   Yielding of PT Cables leads to
                                                                                                                                                                            reduction of working stress
                                                                                                      0.2


                          PT Yielding                                                                  0
                                                                                                            0          0.005                          0.01         0.015        0.02
                                                                                                                                                         PT Strain
        SDOF                         vs.       MDOF Study
•   Will help determine behavior           •   Will help determine behavior
    impact of:                                 impact of:
     – Ratio of PT-Fuse strength                – Higher mode influence on rocking
     – Ratio of frame to fuse stiffness              • Help define practical height limit
     – Increase in PT force due to              – Frame flexibility and coupling
       elongation of cables                          • Benefit of tapered fuse
•   Accurate up to 3-4 stories                  – More realistic fuse modeling (e.g.
                                                  Ibarra hysteretic model)
•   Output:
                                                – A/B ratio (fuse demand)
      Dmax, amax
                                           •   Up to 10 stories (higher?)
                                           •   Output:
                                                 Dmax, amax
                                                 Toe uplift, demand in fuse
                                                 Forces in frame
                                                 Yielding of PT cables?
SDOF Time History Study

     Farrow & Kurama’s
    Matlab SDOF Program
               Post-tension/Brace System
                                                                              Fuse System




                                                          Force
                                                                          b                       c
Force

        a,f     b               e   d     c
                                                                                Fuse Strength     Eff. Fuse
              Hardening of PT                                                                     Stiffness
                                                                      a                   d
         g
                                        PT Strength                                              Drift

          Frame Stiffness
                                                             g        f             e
                                        Drift



SDOF Study
                                                                          Combined System
                                                                          b                       c
•



                                                         Force
        Using highlighted parameters
•       Matlab program developed by
        Farrow & Kurama
                                                                      a                   d
                                                                                                  2x Fuse
          – Engineering Structures, 26,
                                                                                                  Strength
            2004, pp1713-1733
                                                     PT
Definitions                                       Strength
                                                                  f                 e
    br = (Fuse Strength)/(PT-Brace Strength)
    bs = (Fuse Stiffness)/(PT-Brace Stiffness)                                    PT – Fuse Strength
                                                                  g
                                                                                                Drift
                      Prototype Building
                        3-Story SAC Building

                                   3@4m
6 bays @ 9m




                            3@4m



                               Seismic Mass:
                                        Roof      = 1034.7 kN-s2/m
                                        Floor     = 955.6 kN-s2/m
                               Loading:
                                        Floor DL (weight)               = 4.6kN/m2
                                        Floor DL (mass)                 = 4.1kN/m2
                                        Roof DL (not incl. penthouse)   = 4.0kN/m2
              4 bays @ 9m               Penthouse DL                    = 5.6kN/m2
                                        Reduced LL                      = 1.0kN/m2
                                        Exterior Wall                   = 1.2kN/m2
    • Purpose:
                             SDOF Study
         Determine the effects of the fuse strength and stiffness
         parameters (βr and βs) on overall system response

    • Parameters Tested:
       – βr = Fuse Strength / Frame uplift strength
       – βs = Fuse Stiffness / Initial frame stiffness
    • Model Basis:
        Incorporates a bilinear elastic model of the frame & PT system
        with an elastic perfectly plastic fuse
                                 Force
Force




                                                             Force
                             +                           =
           Displacement                  Displacement                 Displacement

        Frame & PT system                    Fuse                  Combined system
          Bilinear elastic               Elastoplastic           Flag-shaped response
               SDOF Study
• Building Physical Attributes
  – Period, T = 0.66 s
  – Total Stiffness (frame & fuse), kMDOF = 87.5 kN/mm
     • Adjusted kSDOF = 133.9 kN/mm
  – Post-uplift PT stiffness k.puMDOF = 2.36 kN/mm
     • Adjusted k.puSDOF = 3.61 kN/mm
  – Mass, m = 1.473 kN*s^2/mm.
  – Weight, W = 14367 kN
  – Yield Strength of fuse + PT system,
       fy = 1793 kN = 0.125*W
    MDOF to SDOF Conversion
                   0.478             
                                       kN  s 
                                               2
                   
                M       0.478                 
                                       mm 
                   
                               0.5175
                                      
                                                 
H
                Ti  0.66 , 0.27 , 0.17 sec




                   0.125W




    A   B   A
                                              Roof Disp.

    H
MDOF to SDOF Conversion
                                                   SDOF

                                       0.125W
                    MSDOF = SMMDOF
                                                               MDOF


2/3H

                                                            Top Disp.
                kSDOF = 1.5kMDOF
                                     - Keep the same mass and yield force
                                     as MDOF

                                     - Adjust the stiffness by 1.5 – assuming
   Equivalent SDOF
                                     center of mass is at 2/3H
                                         - SDOF displacements must be multiplied
                                         by 1.5 to return back to MDOF space
       TSDOF = T1,MDOF
                 SDOF Study
• Variable Parameters Tested
  – Spectral Acceleration Levels:
     Sa = 0.625g, 0.125g, 0.25g, 0.5g, 1.0g, 1.5g
                Elastic range         Inelastic range
  – βr = 1.25, 1.0, 0.5 (fuse strength/frame uplift strength)
  – βs = 1.0, 0.5, 0.33 (fuse stiffness/frame stiffness)


  – Sample hysteretic response for each system is shown
    on next slide
                              SDOF Study
                            Effects of changing βr
                             with constant βs = 1




  βr > 1: Theoretically         βr = 1: Maximizes energy   βr < 1: Provides factor of
Results in large residual          dissipation with low     safety against residual
  displacements (time             residual displacement    displacement at the cost
history response shows                                       of energy dissipation
   no residual disp.)
                           SDOF Study
                       Effects of changing βs
                        with constant βr = 1




As fuse stiffness decreases compared to the frame stiffness, the energy dissipation
                   decreases, assuming constant initial stiffness

However, a change in fuse stiffness is likely to result in a change in total stiffness,
                              change in period, etc.
  Equivalent MDOF Displacement
Elastic Perfectly Plastic vs. Bilinear Elastic/Elastic Perfectly Plastic
                   1.6

                   1.4                                                                             EPP

                   1.2                                                                             Br=1.25 Bs=1


                    1
                             Sa = 1g                                                               Br=1.25 Bs=0.5
    Sa Level (g)




                                                                                                   Br=1.25 Bs=0.5

                   0.8                                                                             Br=1.0 Bs=1
                                                                                                   Br=1 Bs=0.5
                   0.6
                                                                                                   Br=1 Bs=0.33
                   0.4                                                                             Br=0.5 Bs=1.0
                                                                                                   Br=0.5 Bs=0.5
                   0.2
                                                                                                   Br=0.5 Bs=0.33
                    0
                         0         0.5          1        1.5          2       2.5       3
                                                     Roof Drift (%)
                                                        At Design Sa Level (1.0g)
                                         BE/EPP System Median Displacements: 1.3-1.6% roof drift
                                             EPP System Median Displacement: 1.8% roof drift

•No major difference in BE/EPP peak displacement can be obtained by tuning βr, βs
•BE/EPP systems perform poorer than EPP system at lower Sa Levels, but better at higher Sa Levels
                                       SDOF Acceleration
                                        EPP System vs. BE/EPP System
               1.6
                                                                                              EPP
               1.4
                                                                                              Br=1.25 Bs=1
               1.2
                                                                                              Br=1.25 Bs=0.5
Sa Level (g)




                1                                                                             Br=1.25 Bs=0.5
               0.8                                                                            Br=1.0 Bs=1
                                                                                              Br=1 Bs=0.5
               0.6
                                                                                              Br=1 Bs=0.33
               0.4                                                                            Br=0.5 Bs=1.0
               0.2                                                                            Br=0.5 Bs=0.5
                                                                                              Br=0.5 Bs=0.33
                0
                     0           0.1         0.2           0.3         0.4          0.5
                                            Acceleration (g)

                                                     At Design Sa Level (1.0g)
                                            BE/EPP System Accelerations: 0.22-0.26g
                                                   EPP System Acceleration: 0.33g

                     •No major difference in BE/EPP peak displacement can be obtained by tuning βr, βs
                     •BE/EPP systems generally performs better than EPP system
Equivalent MDOF Residual Displacement
              1.6


              1.4


              1.2


               1                                             b r = 1.25, b s = 1
                                                             b r = 1.25, b s = 0.5
     Sa (g)




              0.8                                            b r = 1.25, b s = 0.33
                                                             b r = 1, b s = 1
              0.6
                                                             b r = 1, b s = 0.5
                                                             b r = 1, b s = 0.33
              0.4
                                                             b r = 0.5, b s = 1

              0.2                                            b r = 0.5, b s = 0.5
                                                             b r = 0.5, b s = 0.33
               0
                    0   0.005         0.01         0.015         0.02                0.025
                          Equivalent MDOF Residual Displacement (%)



   All BE/EPP systems display virtually no residual displacement
    SDOF
Elastic Perfectly
Plastic System




              At Design Sa Level (1.0g)
  Median Displacement: 1.5% roof drift
  Median Acceleration: 0.3 g
  Median Residual Displacement: 1% roof drift
        SDOF
Bilinear Elastic System




                  At Design Sa Level (1.0g)
      Median Displacement: 2% roof drift
      Median Acceleration: 0.35 g
      Median Residual Displacement: 0.005% roof drift
                 SDOF Conclusions
•   Within a reasonable range, fuse strength and stiffness βr and βs are not
    critical to the overall structure response

•   Residual drift of all systems studied is essentially zero

•   Flag-shaped response provides slightly better drift and acceleration
    performance compared to the elastoplastic model at 1.0g design-level
    ground acceleration

•   Varying the parameters βr and βs allows customization of the shape of the
    hysteretic response

•   Realistic frame model
    underwent approximately
    1.5% drift at 1.0g design-
                                    Force




                                                                Force
    level ground motion


                                            Displacement                Displacement
      OpenSees
MDOF Time History Study I
Elastic Perfectly Plastic (EPP) Fuse, non-degrading
                   No PT Yielding




                                                  MDOF-I, EPP
                            Cyclic Response
                                                             4000
                                                                        Hardening = 0
                                                             3000       PostCap Softening = -0.02
                                                                        Strength Det. = 0
                                                                        Unloading Stiff Det. = 0
                                                             2000       Accelerated Stiff. Det. = 0
                                                                        PostCap Strength Det. = 0

                                                             1000




                                         Base Shear (kN)
                                                                 0


                                                             -1000


                                                             -2000


                                                             -3000
                                                                                                                              Behavior
                                                                                                                       Global 3-story Frame
                                                             -4000
                                                                -0.06        -0.04           -0.02         0            0.02          0.04     0.06
                                                                                                          RDR

                                                              500

                                                              400

                                                              300


        A       B     A                                       200
                                          Axial Force (kN)




                                                              100

                                                                0
This model is intended to validate the
                                                             -100
response of the SDOF model.
                                                             -200

                                                             -300
V = 0.125W
                                                             -400                                             Bilinear Fuse Behavior
PT = 1055kN, Vp,fuse = 1687kN
br = 1.0
                                                             -500
                                                               -0.04     -0.03       -0.02     -0.01        0        0.01      0.02     0.03   0.04
                                                                                                       Link Strain

                                                                                                                                        MDOF-I, EPP
                         Ground Motion Database
                         80 Records, Non-near field events

         1.5
                                                           7
                             Response Spectrums
                                                       6.8


                                                       6.6
          1
                                                       6.4
Sa (g)




                                                      Mw
                                                       6.2


         0.5                                               6


                                                       5.8


                                                       5.6                          Magnitude versus Distance
          0                                                10   15   20   25   30    35    40   45   50   55   60   65
               0   0.5         1        1.5       2
                                                                                      R (km)
                           Period (s)
   Maximum Interstory Drift vs. Sa(T1)
                                         2.2%
                        1.6
                                                                                     2/50 Level
                        1.4


                        1.2
                                  1.4%

                         1                                                           10/50 Level
          Sa(T 1) (g)




                        0.8
                                                                       Chose records with scale
                        0.6                                         factors less than or equal to 4.0


                        0.4              Unscaled records

                                                                    Median MDOF response matches
                        0.2
                                                                    median SDOF response

                         0
                              0     0.02         0.04        0.06    0.08          0.1
                                                   Maximum IDR


The yellow squares represent the median, 16th and 84th percentile response.
                                                                                             MDOF-I, EPP
MDOF Time History Study II

     Pinching, Degrading (PD) Fuse
        PT Yielding at 2.5% uplift




                                     MDOF-II, PD
                          Cyclic Response                                                                                        PT Yielding
                                                           2500
                                                                       Hardening = 0
                                                           2000        PostCap Softening = -0.02
                                                                       Strength Det. = 0
                                                           1500        Unloading Stiff Det. = 0
                                                                       Accelerated Stiff. Det. = 0
                                                           1000        PostCap Strength Det. = 0




                                         Base Shear (kN)
                                                             500

                                                                  0

                                                            -500

                                                           -1000

                                                           -1500

                                                           -2000                                                          Behavior
                                                                                                                   Global3-story Frame
                                                           -2500
                                                              -0.06         -0.04        -0.02          0          0.02       0.04       0.06
                                                                                                       RDR

                                                           500                                                            4% shear strain cap
                                                           400
                                                                      PD Fuse Behavior
                                                           300


        A      B      A                                    200
                                        Axial Force (kN)




                                                           100


This model is intended to represent a                         0


more realistic MDOF response with a                        -100

                                                           -200
degrading fuse and PT yielding.                                                                                       Pinching
                                                           -300

                                                           -400
V = 0.125W                                                   50% residual
                                                           -500
PT = 1055kN, Vp,fuse = 1687kN                                -0.08       -0.06      -0.04        -0.02
                                                                                                    Link Strain
                                                                                                               0      0.02      0.04     0.06


br = 1.0
                                                                                                                                     MDOF-II, PD
         Maximum Interstory Drift vs. Sa(T1)
                                     2.7%
                        1.6
                                                                                               2/50 Level
                        1.4
                                                          10/50 & 2/50 Medians increased
                        1.2                                by 14 and 23% from EPP Fuse
                                  1.6%

                         1                                                                     10/50 Level
          Sa(T 1) (g)




                        0.8
                                            PT Yielding                          Chose records with scale
                        0.6                                                   factors less than or equal to 4.0


                        0.4              Unscaled records

                        0.2


                         0
                              0   0.02     0.04    0.06    0.08    0.1      0.12    0.14    0.16
                                                       Maximum IDR


The yellow squares represent the median, 16th and 84th percentile response.
                                                                                                        MDOF-II, PD
Now let’s focus on one EQ…
              1.6


              1.4


              1.2


               1
Sa(T 1) (g)




              0.8


              0.6
                                      Examine response for one EQ
                                      at each hazard level.
              0.4
                                      (EQ is NR94hol)
              0.2


               0
                    0   0.02   0.04   0.06    0.08    0.1   0.12   0.14   0.16
                                          Maximum IDR


                                                                                 MDOF-II, PD
                                                          NR94HOL, Unscaled
    Interstory Drift Ratio
                                                              Time History Response
                                 0.01

                                            0

                             -0.01
                                                 0        5    10   15        20         25   30   35           40
                                                                           Time (s)
Base Shear (kN)




                             5000
                                                                                                        V
                                                                                                            design
                                            0

                             -5000
                                                 0        5    10   15        20         25   30   35           40
                                                                           Time (s)
                                                     -3
                                                 x 10
                                            5                            Negligible Uplift
                             Uplift Drift




                                            0

                                            -5
                                                 0        5    10   15        20         25   30   35           40
                                                                           Time (s)
                                                                                                                     MDOF-II, PD
                                                     NR94HOL, Unscaled
                                                Acceleration Response per Floor
                                       1
Horizontal Acc. (%g)




                                   0.5

                                       0

                             -0.5
                                                                                      Horizontal Acc.
                                       -1
                                            0    5     10   15      20      25   30          35          40
                                                                 Time (s)

                                       2
                  Vertical Acc. (%g)




                                       1

                                       0

                                       -1

                                       -2                                             Vertical Acc.
                                       -3
                                            0    5     10   15      20      25   30          35          40
                                                                 Time (s)
                                                                                                        MDOF-II, PD
                                         NR94HOL, Sa(T1) = 1.0g
    Interstory Drift Ratio
                              0.05
                                              Time History Response
                                 0

                             -0.05
                                     0    5    10   15      20      25   30   35           40
                                                         Time (s)
Base Shear (kN)




                             5000
                                                                                   V
                                                                                       design

                                 0

                             -5000
                                     0    5    10   15      20      25   30   35           40
                                                         Time (s)
                              0.02
    Uplift Drift




                                 0

                             -0.02
                                     0    5    10   15      20      25   30   35           40
                                                         Time (s)
                                                                                                MDOF-II, PD
                                                NR94HOL, Sa(T1) = 1.0g
                                                Acceleration Response per Floor
                                       1
Horizontal Acc. (%g)




                                   0.5

                                       0

                             -0.5
                                                                                    Horizontal Acc.
                                       -1
                                            0    5   10   15      20      25   30         35           40
                                                               Time (s)

                                       4
                  Vertical Acc. (%g)




                                       2

                                       0

                                       -2
                                                                                    Vertical Acc.
                                       -4
                                            0    5   10   15      20      25   30         35           40
                                                               Time (s)
                                                                                                      MDOF-II, PD
                                         NR94HOL, Sa(T1) = 1.5g
    Interstory Drift Ratio
                              0.05
                                               Time History Response
                                 0

                             -0.05
                                     0     5     10   15      20      25   30   35           40
                                                           Time (s)
Base Shear (kN)




                             5000
                                                                                     V
                                                                                         design

                                 0

                             -5000
                                     0     5     10   15      20      25   30   35           40
                                                           Time (s)
                              0.05
    Uplift Drift




                                 0

                             -0.05
                                     0     5     10   15      20      25   30   35           40
                                                           Time (s)
                                                                                                  MDOF-II, PD
  Zooming in on response between 8-15 seconds…
    Interstory Drift Ratio
                              0.05

                                 0

                             -0.05
                                     8   9   10   11         12   13   14   15
                                                    Time (s)
Base Shear (kN)




                             5000

                                 0

                             -5000
                                     8   9   10   11         12   13   14   15
                                                    Time (s)
                              0.05
    Uplift Drift




                                 0

                             -0.05
                                     8   9   10   11         12   13   14   15
                                                    Time (s)
                                                                                 MDOF-II, PD
                                NR94HOL, Sa(T1) = 1.5g
                                Acceleration Response per Floor
                       2
Horizontal Acc. (%g)




                       1

                       0

                       -1
                                                                    Horizontal Acc.
                       -2
                            0    5   10   15      20      25   30         35           40
                                               Time (s)

                       5
Vertical Acc. (%g)




                       0


                                                                    Vertical Acc.
                       -5
                            0    5   10   15      20      25   30         35           40
                                               Time (s)
                                                                                      MDOF-II, PD
               Uplift related to vertical accelerations…8-15 sec…

                              0.05                                                          Lift off                     Touch down
Uplift Drift




                                                            0

               -0.05
                                                                 8             9          10           11         12          13      14    15
                                                                                                         Time (s)
               Vert. Roof Acc. (%g) Horiz. Roof Acc. (%g)




                                                            2

                                                            0

                                                            -2
                                                                 8             9          10             11         12        13      14    15
                                                                                                           Time (s)
                                                                     Initiates vertical acceleration spike
                                                            5

                                                            0

                                                            -5
                                                                 8             9          10           11         12          13      14    15
                                                                                                         Time (s)
                                                                                                                                           MDOF-II, PD
                        Maximum Accelerations versus Sa(T1)

              1.6                                                                        1.6


              1.4                                                                        1.4


              1.2                                                                        1.2


               1                                                                          1
Sa(T 1) (g)




                                                                           Sa(T 1) (g)
              0.8                                                                        0.8


              0.6                                                                        0.6


              0.4                                                                        0.4


              0.2                                                                        0.2


               0                                                                          0
                    0    0.5         1             1.5           2   2.5                       0   1   2       3          4          5       6     7
                               Maximum Horizontal Acceleration                                          Maximum Vertical Acceleration

                                           %g                                                                       %g



                                                                                                                                         MDOF-II, PD
                            Panel Design
                           Vp,fuse = 1687 kN

                                                     ECC Panel
                                                     f’c = 57 MPa
                                                     Shear strength = 0.8√f’c**
                                                     Thickness = 150mm
                                                     Required height = 1862mm

                                                     Steel wall with Slits
                                                     Fy = 345 MPa
                                                     2-rows of 50mm deep links
                                                     Thickness = 15mm
                                                     Required height = 1323mm
       A      B      A
                                      B=1000mm
PT = 1055kN, Vp,fuse = 1687kN
br = 1.0

                                          **taken from Gustavo Parra-Montesinos’ coupling beam tests
                            Panel Design
                           Vp,fuse = 1687 kN
                                                      Reduced Web Beams
                                                      f’c = 345 MPa
                                                      Assuming pure shear of web links**
                                                      No. Beams = 12


                                                           diameter = 200mm




                                                                                      537mm



                                                             100mm
       A      B      A
                                                           W530x101 (W21x68)

PT = 1055kN, Vp,fuse = 1687kN
br = 1.0
                                ** This assumption is conservative (80% of measured), since at
                                larger deformations the a diagonal truss forms within the web posts.
                            Panel Design
                           Vp,fuse = 1687 kN
                                                  ECC Panel
                                                  f’c = 52 MPa
                                                  Thickness = 150mm
                                                  1 layer of wire mesh rein.
                                                  2 #3 perimeter bars
                                                  Wire diameter = 5.7mm
                                                  No. Beams = 23
                                                                  V=75kN




                                       d1=350mm                            d1

       A      B      A

PT = 1055kN, Vp,fuse = 1687kN
br = 1.0                                             Length =700mm
                                                                               Tapered HPFRCC Beams
                                                                                            OpenSees Fiber Elements
                                                                                                              (no shear deformations)
                                                                                                   V                                                                                                                                          V


                                      d1=350mm                                                               d1=150mm                                                          d1=350mm                                                              d1=200mm




                                                                  Length =700mm                                                                                                                             Length =700mm

                         100                                                                                                                                  100
Applied Shear (kN)




                                                                                                                                     Applied Shear (kN)
                                 80                                                                                                                                   80

                                 60                                                                                                                                   60

                                 40                                                                        d1 = 350mm                                                 40
                                                                                                           d2 = 150mm
                                 20                                                                    Length = 700mm                                                 20
                                                                                                   Discrete Beams = 10
                                      0                                                                                                                                    0
                                          0       0.002   0.004       0.006    0.008 0.01        0.012       0.014   0.016   0.018                                             0       0.002   0.004       0.006    0.008 0.01        0.012       0.014   0.016   0.018
                                                                                   Drift                                                                                                                                Drift
                                              4                                                                                                                                    4
                                          x 10                                                                                                                                 x 10
                                      8                                                                                                                                    8
                                                                                                                                                          Moment (kN-mm)
                     Moment (kN-mm)




                                      6                                                                                                                                    6

                                      4                                                                                                                                    4


                                      2                                                                                                                                    2


                                      0                                                                                                                                    0
                                          0           1           2             3           4            5           6          7                                              0           1           2             3           4            5           6          7
                                                                              Curvature (1/mm)                                -5                                                                                   Curvature (1/mm)                           x 10
                                                                                                                                                                                                                                                                   -5
                                                                                                                         x 10
Stanford Panel Testing
    Configuration
1.22 m   1.22 m   1.22 m
                                      Blume Center
                                    Lab Configuration

                                    •   Columns:
                                         – Section: probably
                           1.22 m          WF24x12 from ASD,
                                           5th ed. (AISC historical
                                           section database)
                                         – Four 24” (610 mm)
                                           deep columns spaced
                           1.22 m          48” (1220 mm) on
                                           center on two sides of
                                           strong floor
                                         – Height: 7’ (2.13 m)
                           1.22 m   •   Floor Beams:
                                         – Section: unknown
                                         – 10.5” (267 mm) flange
                                           width
                                    •   Bolt Holes:
                                         – 7/8” (22mm) Bolt
                                           Holes
                                         – Square pattern of 4
                                           bolts spaced 5” (127
                                           mm) on center


     Plan View
     Blume Center Lab Configuration




                                                     7ft
                                                  (2.13 m)




     Column Elevations                Column A-4 Elevation
(bolt hole locations approximate)   (current test configuration)
         Proposed Test Configuration
                           -- Plan View--



           Slotted Holes              Actuator

                               Load



 Floor                Specimen:                  Columns
Beams                 1m x 0.5m
              Proposed Test Configuration
                      -- Elevation View--




   Specimen bolted
    between plates
     welded to Tee           End plate for
       sections              actuator load


Floor level
              Proposed Test Configuration
                      -- Section View--


  End plate for
 actuator loads
                                           Tee section bolted
                                          to floor beams with
This Tee section                            welded plates to
  is allowed to        Specimen             attach specimen
   slide using
slotted bolt holes
Horizontal Panel Configuration
• Advantages:
  – No column overloads
  – Possible compatibility with Professor
    Billington’s masonry research project
  – Simpler & safer setup

• Disadvantage:
  – Difficult to inspect underside of panel
    during test
                Test Specimens
• ECC Volume Constraints
   – 75L mixer available
   – Specimens must be cast in single pour
       • 1m x 0.5m x 0.127m(5in.) = 64L


• Number of Specimens
   – Number of panel types = 3?
     (“butterfly” ECC, rectangular ECC, steel panel w/ slits)
   – Number of specimens per panel type = ?




Butterfly ECC          Rectangular ECC           Steel w/ Slits

				
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