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Yeong-Jong MoonYeong-Jong Moon
Dept. of Civil and Environmental Engineering
KAIST, Korea
The 17th Engineering Mechanics Conference of ASCEUniversity of Delaware, Newark, DEJune 13 - 16, 2004
Application of Some MR Damper-based Control Systems for Seismic Protection of
Benchmark Base Isolated Building
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 22
Contents
Introduction
Benchmark Base Isolated Building
MR Damper-based Control System
Control Algorithms
Numerical Simulation Results
Conclusions
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 33
Introduction
Base isolation systems, such as elastomeric, friction, and lead-rubber bearing systems, have been accepted as an effective means for seismic protection of building structures.
Base isolation systems can reduce inter-story drifts and floor accelerations, whereas base displacements in those systems may be increased. expensive loss of space for seismic gap
Hybrid-type base isolation systems employing additional active control devices have been studied to limit base drift.
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 44
Because of its adaptability and reliability, an MR damper- based hybrid-type base isolation system could solve the large base drift problem of the passive-type base isolation system.
To systematically compare the effectiveness of control systems for base isolated buildings, the benchmark study developed by Narasimhan et al. (2003) based on input from the ASCE structural control committee.
In the benchmark problem, three different kinds of base isolation systems, such as linear elastomeric with low damping, frictional systems, and bilinear or nonlinear elastomeric systems, are considered.
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 55
To verify the effectiveness of the MR damper-based control systems considering some control algorithms, such as modified clipped-optimal control, maximum energy dissipation, and the modulated homogeneous friction algorithms, for seismic protection of base isolation system.
Objective of This Study
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 66
Benchmark Structure
an eight-story base isolated steel-braced framed building
width: 82.4m and 54.3m
similar to existing buildings in LA, California
Benchmark Base Isolated Building
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 77
Base Isolation Systems Considered
Linear elastomeric isolation system: 92 low damping elastomeric bearings
Nonlinear isolation system:
61 friction pendulum bearings and 31 linear elastomeric bearings
Supplemental active or semiactive control devices:
16 active or semiactive control devices at the isolation level
(8 in X- and 8 in Y-direction)
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 88
Control Diagram for MR Damper-based System
MR Damper-based Control System
Controller(Control Algorithm)
gx
bb xx ,
v
MR Damper
MRf
my
eyBase Isolated
Building Structure
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 99
Original Clipped-Optimal Control Algorithm
Control Algorithms
OptimalControl(LQG)
gx
bb xx ,
v
MR Damper
MRf
my
eyBase Isolated
Building Structure
MRMRc fffHVv max
Clipped Algorithm(0 or Vmax)
cf
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 1010
Modified Clipped-Optimal Control Algorithms
OptimalControl(LQG)
gx
bb xx ,
v
MR Damper
MRf
my
eyBase Isolated
Building Structure
Clipped Algorithm
(Vc)
cf
MRMRcc fffHVv
max
maxmaxmax
,0
,)(
fffor
ffforffVV
c
ccc
Modified version proposed by Yoshida and Dyke (2004)
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 1111
OptimalControl(LQG)
gx
bb xx ,
v
MR Damper
MRf
my
eyBase Isolated
Building Structure
Clipped Algorithm
(Vc)
cf
MRMRcc fffHVv
Another modified version proposed in this study
MRc
MRcMRcc ffforV
fffforffVV
max
maxmax ,)(
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 1212
Maximum Energy Dissipation Algorithm
This algorithm considers a Lyapunov function that represents the relative energy in the structure (Jansen and Dyke, 2000). gx
bb xx ,
v
MR Damper
MRf
my
eyBase Isolated
Building Structure
Clipped Algorithm(0 or Vmax)
MRb fxHVv max
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 1313
Modulated Homogeneous Friction Algorithm
This algorithm originally developed for use with variable friction devices was modified for MR dampers (Jansen and Dyke, 2000). gx
bb xx ,
v
MR Damper
MRf
my
eyBase Isolated
Building Structure
Clipped Algorithm(0 or Vmax)
MRn ffHVv max)( stgf nn
, in which , the most recent local extrema in the deformation of the MR damper )( st }0)(:0{min xtxs
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 1414
Numerical Simulation Results
Control Algorithms Considered - Original modified clipped-optimal for linear system (OCO) - Skyhook control for nonlinear system (SHC)
- Modified clipped-optimal by Yoshida and Dyke (MCO-1) - Modified clipped-optimal proposed herein (MCO-2) - Maximum energy dissipation (MED) - Modulated homogeneous friction (MHF)
Base Isolation Systems Considered - Linear elastomeric isolation system - Nonlinear friction isolation system
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 1515
Evaluation Criteria (Narasimhan et al., 2003)
- J1: normalized peak base shear
- J2: normalized peak structure shear
- J3: normalized peak base displ. or isolator deformation
- J4: normalized peak inter-story drift
- J5: normalized peak absolute floor acceleration
- J6: normalized peak force generated by all control devices
- J7: normalized RMS base displacement
- J8: normalized RMS absolute floor acceleration
- J9: normalized total energy absorbed by all control devices
* In this study, the results of each algorithm are normalized by those of OCO in linear case and SHC in nonlinear case.
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 1616
Earthquakes Used (Narasimhan et al., 2003)
Both the fault-normal (FN) and the fault-parallel (FP) components of
- Newhall record in Northridge earthquake
- Sylmar record in Northridge earthquake
- El Centro record in Imperial Valley earthquake
- Rinaldi record in Northridge earthquake
- Kobe record in Hogoken Nanbu earthquake
- Jiji068 record in Jiji earthquake
- Erzinkan record in Erzinkan earthquake
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 1717
Linear Elastomeric Isolation System
Earthquakes J1 J2 J3 J4 J5 J6 J7 J8 J9
NewhallFP:X FN:Y 1.06 0.97 1.27 1.09 0.97 0.95 1.62 0.76 0.67
FP:Y FN:X 1.00 0.98 1.26 1.08 0.72 0.91 1.90 0.72 0.67
SlymarFP:X FN:Y 0.99 1.07 1.09 1.11 1.08 1.40 1.19 0.88 0.84
FP:Y FN:X 1.46 1.15 1.05 1.14 2.40 2.33 1.15 0.85 0.89
El CentroFP:X FN:Y 0.89 1.05 2.30 1.04 0.37 0.29 3.25 0.52 0.63
FP:Y FN:X 0.89 1.09 2.40 1.21 0.41 0.26 3.42 0.58 0.61
RinaldiFP:X FN:Y 0.91 1.03 1.21 1.03 0.81 0.97 1.32 0.87 0.76
FP:Y FN:X 0.85 1.01 0.98 1.05 0.75 0.97 1.22 0.68 0.77
KobeFP:X FN:Y 0.91 0.93 1.35 1.11 0.88 1.11 2.19 0.81 0.70
FP:Y FN:X 0.99 1.06 1.38 1.28 0.79 1.21 2.42 0.89 0.63
JijiFP:X FN:Y 1.18 1.06 1.04 1.10 1.81 2.44 1.22 0.99 0.86
FP:Y FN:X 1.30 1.02 1.04 1.04 2.33 3.62 1.31 1.06 0.88
ErzinkanFP:X FN:Y 0.99 0.95 1.17 0.90 0.97 1.01 1.28 0.85 0.76
FP:Y FN:X 0.91 0.84 1.16 0.96 1.00 1.31 1.26 0.71 0.79
Control performance of MCO-1 normalized by OCO
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 1818
Discussion
- All the peak floor accelerations (J5) are reduced up to 63% except of the Sylmar and Jiji cases while maintaining the similar level of the peak inter-story drifts (J4) (a 28% increase ~ a 10% decrease).
- All the peak isolator deformations (J3) in MCO-1 are larger than those in OCO (a 4%~140% increase) except of the Rinaldi case (a 2% decrease).
- In the El Centro case, MCO-1 significantly reduces the peak floor acceleration (J5), whereas is drastically increases the peak isolator deformation (J3) .
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 1919
Control performance of MCO-2 normalized by OCOEarthquakes J1 J2 J3 J4 J5 J6 J7 J8 J9
NewhallFP:X FN:Y 1.01 0.95 1.03 1.00 1.02 0.98 1.09 0.86 0.94
FP:Y FN:X 0.90 0.88 1.04 1.09 0.73 0.97 1.32 0.91 0.94
SlymarFP:X FN:Y 1.01 1.02 1.05 1.07 0.96 1.00 1.02 0.98 0.98
FP:Y FN:X 0.92 0.92 1.10 1.00 0.92 0.94 1.12 0.80 0.98
El CentroFP:X FN:Y 1.17 1.19 1.34 1.15 0.97 0.86 1.48 0.78 0.90
FP:Y FN:X 1.22 1.24 1.96 1.47 1.18 0.83 1.72 0.91 0.93
RinaldiFP:X FN:Y 1.05 1.01 1.03 0.95 1.07 0.97 1.03 0.97 0.97
FP:Y FN:X 0.97 1.01 0.91 0.97 1.01 0.97 0.84 0.68 0.97
KobeFP:X FN:Y 1.00 1.02 1.00 1.08 0.98 1.01 1.26 0.94 0.95
FP:Y FN:X 1.15 1.15 1.04 1.31 0.95 1.05 1.64 1.08 0.90
JijiFP:X FN:Y 0.99 1.00 0.99 0.99 0.97 1.01 1.01 0.97 0.98
FP:Y FN:X 0.90 0.91 0.99 0.92 0.86 0.99 1.05 0.82 0.95
ErzinkanFP:X FN:Y 0.98 0.95 0.99 0.91 0.98 1.01 1.01 0.97 0.98
FP:Y FN:X 0.90 0.83 1.08 0.95 0.89 0.96 0.92 0.76 0.98
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 2020
Discussion
- The overall performance of MCO-2 is similar to that of MCO-1.
- All the peak floor accelerations (J5) are reduced up to 27% except of the El Centro and Rinaldi cases.
- Increases in J5 of MCO-2 are not large compare with those of MCO-1 (e.g., an 18% increase under El Centro in MCO-2; a 140% increase under Sylmar in MCO-1).
- It is verified that MCO-2 could be the more reliable control algorithm under various ground motions.
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 2121
Earthquakes J1 J2 J3 J4 J5 J6 J7 J8 J9
NewhallFP:X FN:Y 0.91 0.93 1.25 0.97 0.73 0.95 1.44 0.82 0.80
FP:Y FN:X 0.93 0.84 1.18 0.93 0.89 0.97 1.68 0.92 0.81
SlymarFP:X FN:Y 0.97 1.04 1.15 0.97 0.82 0.93 1.33 0.93 0.80
FP:Y FN:X 0.88 0.89 0.95 0.98 0.89 0.98 1.04 0.76 0.86
El CentroFP:X FN:Y 1.01 1.04 1.36 1.00 0.89 0.95 1.72 0.83 0.86
FP:Y FN:X 0.87 1.10 1.96 1.22 1.10 1.15 2.39 0.98 0.85
RinaldiFP:X FN:Y 0.92 1.04 1.05 1.04 0.82 0.93 1.32 0.97 0.82
FP:Y FN:X 0.81 0.97 1.03 1.03 0.73 0.97 1.03 0.68 0.79
KobeFP:X FN:Y 0.77 0.89 1.05 0.98 0.78 1.28 1.24 0.93 0.91
FP:Y FN:X 0.93 0.98 1.04 1.14 0.70 1.27 2.01 1.17 0.86
JijiFP:X FN:Y 1.06 1.12 1.20 1.11 0.90 0.75 1.28 1.02 0.76
FP:Y FN:X 0.98 1.01 1.16 1.03 0.99 0.95 1.29 0.85 0.77
ErzinkanFP:X FN:Y 0.91 0.95 1.04 0.88 0.78 0.97 1.30 0.93 0.76
FP:Y FN:X 0.89 0.81 1.13 0.90 0.98 0.92 1.02 0.68 0.84
Control performance of MHF normalized by OCO
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 2222
Discussion
- The control performance of MHF is quite good.
- All the peak floor accelerations (J5) are reduced by 30% ~1% except of the El Centro case (a 10% increase).
- All the peak inter-story drifts (J4) are within the reasonable ranges (a 12% decrease ~ a 22% increase).
- MHF could be considered as one of the promising control algorithms for base isolated buildings employing MR dampers in the linear elastomeric case.
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 2323
Earthquakes J1 J2 J3 J4 J5 J6 J7 J8 J9
NewhallFP:X FN:Y 1.16 1.11 1.19 1.00 1.12 0.72 1.17 0.88 0.77
FP:Y FN:X 1.05 1.19 1.15 1.20 0.99 0.83 1.04 0.98 0.84
SlymarFP:X FN:Y 1.18 1.23 1.19 1.06 0.85 0.68 1.26 0.88 0.74
FP:Y FN:X 1.16 1.20 1.20 1.36 0.91 0.77 1.37 0.95 0.73
El CentroFP:X FN:Y 0.97 0.84 1.24 0.89 0.90 0.85 1.15 0.84 0.70
FP:Y FN:X 0.85 0.93 0.97 1.01 0.97 0.98 0.98 0.85 0.70
RinaldiFP:X FN:Y 1.12 1.04 1.07 0.92 0.71 0.76 1.14 0.85 0.75
FP:Y FN:X 1.10 1.08 1.07 0.87 0.82 0.66 1.15 0.84 0.75
KobeFP:X FN:Y 1.12 0.90 1.39 0.96 0.91 0.69 1.17 0.85 0.56
FP:Y FN:X 1.11 0.96 1.42 1.04 0.91 0.68 1.16 0.87 0.58
JijiFP:X FN:Y 1.16 1.14 1.27 1.03 0.86 0.86 1.14 0.98 0.88
FP:Y FN:X 1.14 1.10 1.25 1.06 1.06 0.87 1.09 1.02 0.88
ErzinkanFP:X FN:Y 1.06 1.06 1.26 0.96 0.88 0.88 1.38 0.88 0.66
FP:Y FN:X 1.06 1.18 1.29 1.03 0.90 0.79 1.45 0.95 0.71
Nonlinear Friction Isolation System
Control performance of MHF normalized by SHC
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 2424
Discussion
- The control performance of MHF is quite good in the nonlinear friction case as well.
- All the peak floor accelerations (J5) are reduced by 29% ~1% except of the Newhall and Jiji cases (12% and 6% increases, respectively).
- All the peak inter-story drifts (J4) are within the reasonable ranges (a 13% decrease ~ a 36% increase).
- MHF could be considered as an appropriate control algorithm for base isolated buildings employing MR dampers in the nonlinear friction case.
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 2525
Conclusions
Some control algorithms, such as MCOs, MED, and MHF, are considered to verify the effectiveness of MR damper-based control systems for seismic protection of a base isolated building.
Most of the control algorithms considered could be beneficial in reducing seismic responses of a benchmark base isolated building.
The modulated homogeneous friction algorithm could be considered as one promising candidate for the nonlinear as well as the linear benchmark base isolated systems.
Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea 2626
Thank you for your attention!