1. NEESR-SG: Controlled Rocking of Steel-Framed Buildings with Replaceable Energy Dissipating Fuses
Greg Deierlein, Paul Cordova, Eric Borchers, Xiang Ma, Alex Pena, Sarah
Billington, & Helmut Krawinkler, Stanford University
Jerome Hajjar, Kerry Hall, Matt Eatherton, University of Illinois
Mitsumasa Midorikawa, Hokkaido University
David Mar, Tipping & Mar Associates and Greg Luth, GPLA

2. Shortcomings of Current Approaches
Throw-away technology:
Structure and Architecture absorbs energy through damage
Large Inter-story Drifts:
Result in architectural & structural damage
High Accelerations:
Result in content damage
& loss of function
Deformed Section – Eccentric Braced Frame

3. New System
Shear Fuse
Post-tensioning
Develop a new structural building system that employs self-centering rocking action and replaceable* fuses to provide safe and cost effective earthquake resistance.
*Key Concept – design for repair

4. Design Concept & Applications
Enhanced alternative to conventional
steel-braced frame
RC wall systems
2. Retrofit of existing steel or RC frame buildings
3. Extensions to other building and structural systems

5. Rocking Design Parameters
Design Variables
PT: Post-tensioning force
Vp: Fuse shear strength
Dimensions A & B Vp
Column Base Reactions
R1 = PT - Vp
R2 = PT + Vp Vp
Overturning moment (& base shear)
Mot = PT·(A) + Vp·(A+B)
Limiting Values
To ensure self-centering:
PT > Vp·(1+B/A)
To ensure dual rocking:
PT > Vp PT
Now I know you’ve been just itching for some equations, so it’s time to do little bit of math, but nothing too complicated. [click through equations and talk about them…] PT R1 R2 A B

6. Pretension/Brace System Fuse System
Base Shear
Drift
a,f b c d e g
PT Strength
Frame Stiffness
Fuse System
Base Shear
Drift a b c d e f g
Fuse Strength
Eff. Fuse
Stiffness b c
Origin-a – frame strain + small distortions in fuse
a – frame lift off, elongation of PT
b – fuse yield (+)
c – load reversal
d – zero force in fuse
e – fuse yield (-)
f – frame contact
f-g – frame relaxation
g – strain energy left in frame and fuse, small residual displacement
Base Shear
2x Fuse
Strength d a PT
Strength e f
PT – Fuse Strength g
Drift
Combined System

7. OpenSees Simulation Model

8. Cyclic Response DESIGN with R = 8.0 A B Global Behavior
4% shear strain cap A B
PD Fuse Behavior
DESIGN with R = 8.0
Vd = 0.125W
PT = 1055kN, Vp,fuse = 1687kN
br = 1.0
Pinching
50% residual

9. Maximum Interstory Drift vs. Sa(T1)
2.7%
2/50 Level
Inelastic Time History Analyses:
20 EQ record pairs, scaled to increasing intensities
Primary EDP: interstory drift
structural limit states
- column lift-off (rocking)
fuse yielding/damage
PT yielding
1.6%
10/50 Level
PT Yielding
Unscaled records
The yellow squares represent the median, 16th and 84th percentile response.

10. Research Scope System Design Development Subassembly Frame/Fuse Tests
- parametric design studies
- shear panel fuse design and testing
- building simulation studies
Subassembly Frame/Fuse Tests
- quasi-static cyclic loading
- PT rocking frame details & response
- panel/frame interaction
- model calibration
Shake Table System Tests
- proof-of-concept
- validation of simulation models
Stanford
NEES - Illinois
E-Defense

11. Shear Fuse Testing - Stanford
Attributes of Fuse
high initial stiffness
large strain capacity
energy dissipation
Candidate Fuse Designs
ductile fiber cementitious composites
steel panels with slits
low-yield steel
mixed sandwich panels
damping devices
Panel Size: 400 x 900 mm

12. Trial Steel Fuse Configurations
thickness t h a L b B
Rectangular Link Panel
Butterfly Panel
KEY PARAMETERS:
Slit configuration
b/t and L/t ratios
Butterfly – b/a ratio
Out of plane bracing

13. Trial Fuse Designs: Rectangular Slits
#4 R56-10BR
#3 R56-10
#4 R56-10BR

15. Subassembly Frame Tests (NEES-Illinois)
Test Configuration
1/3 scale planar rocking frame with realistic details
quasi-static
System Response
structural details & PT
various fuse types
indeterminate shear-fuse/frame interaction
Simulation model validation
NEES - Illinois

16. NEES-Illinois Subassembly Tests (1/2 scale)
Front View
Side View

17. Controlled Rocking System
Replaceable energy dissipating fuses
Post-tensioning strands
Stiff braced frame (elastic)
Pivoting collector beam connection
Rocking base trough

18. ROCKING FRAME DETAILS
Rocking Base Detail

19. SPECIMEN DETAILING – PT Top Anchor

20. Shake Table Validation Test (E-Defense)
Large (2/3 scale) frame assembly
Validation of dynamic response and simulation
Proof-of-Concept
construction details
re-centering behavior
fuse replacement
Collaboration & Payload Projects

21. E-Defense “Testbed” Structure
2.7m
Section – Testbed & Frame
Plan View (Shake Table)

22. Rocking Braced Frame w/Post Tensioning
Orinda City Offices
Architect: Siegel and Strain Architects

23. Rack Storage Structure w/ protective rocking
次にトラス柱構造の地震応答解析について報告します。
解析の対象とするトラス柱構造を示します。用途はラック倉庫，高さ49.7m，
1次固有周期は2.73です。入力地震はHachinohe EW 50kineです。
ダンパー継ぎ手は静的解析をもとに中小地震に対し
ダンパー継ぎ手のフランジが塑性化しないような位置へ配置しました。
Rocking Joint
Height: 50 m
Prof. Akira Wada - Japan

25. Innovation and Design Research
Thematic Concept
Life Cycle Design for Earthquake Effects
damage control & design for repair
Engineering Design Features
controlled rocking & self-centering
energy dissipating replaceable fuses
Performance-Based Engineering Framework
quantification of decision variables (losses, downtime)
integration of hazard, response, damage, loss
Development & Validation
testing and analysis