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Project: Structural Seismic Process Simulation and Control under Multiple Ground Motions
PI: Prof. Hongnan Li
Dalian University of Technology, China
Co-PI : Prof. Satish Nagarajaiah
PI:Prof. Hong-
Nan LiDalian University of Technology,
China
Co-PI:Prof. Satish Nagarajaiah
Rice University, USA
1. Background: Disasters
A lot of high-rise and large-span structures have been built or are under construction in China in recent years.
National Stadium-- "Bird's Nest"
New CCTV Building National Swimming Center--"Water Cube"
National Grand Theater--"Eggshell"
Diwang Building
In Shenzhen
Jinmao Tower
In Shanghai
Oriental Peal TV Tower
Sutong Bridge in Jiangsu
Huanqiu Center
These modern structures are
flexible and will be subjected to
earthquakes, wind excitations
and other natural disasters.
Earthquake Flood
Mudslide
1. Background: Disasters
Typhoon
Wenchuan Great Earthquake (Ms 8.0)
Time : 14:28, May 12, 2008
Location : Wenchuan County, Sichuan
Province in China
Dead and Missing People: 87,000
1. Background: Disasters
Yushu Earthquake (Ms 7.1)
Time : 07:49, April 14, 2010
Location : Yushu County, Qinghai
Province in China
Dead People: 2698
1. Background: Disasters
1. Background: Disasters
Damage of a Transmission Tower Damage of BuildingsDamage of a Stadium
The typhoon is also a major disaster in China and a lot of structures are damaged due to typhoon every year.
Typhoon in 2006 Typhoon in 2007 Typhoon in 2008 Typhoon in 2009 Typhoon in 2010
1. Background: DECISEW Plan
National Natural Science Foundation of China (NSFC)
Damage Evolution of Civil Infrastructures under Strong Earthquake and Wind (DECISEW) Plan
The property and law of strong earthquake and strong typhoon
fields.
The process and mechanism of damage
evolution of major infrastructures.
Focus
Funding
1. Background: DECISEW Plan
International Collaborative Research Project
NSFC
PI of DECISEW Project with PI of NEES of NSF
DECISEW: Damage Evolution of Civil Infrastructure under Strong Earthquake and Wind (China)NEES: Network for Earthquake Engineering Simulation (USA)
The theoretical model of strong earthquake and strong typhoon fields
The damage evolution process and collapse mechanism of major civil structures
The integrated simulation system of damage evolution.
Objective
1. Background: DECISEW PlanProf. Hong-Nan Li, PI of DECISEW Project, “The seismic destroy mechanism and process simulation of structures with multi-dimensional nonlinearities” (90815026), 2009-2012.
Prof. Satish Nagarajaiah, PI of NEES Project, “NEESR-SG: Development of Next Generation Adaptive Seismic Protection Systems” (NSF-CMMI-0830391), 2008-2013.
International Collaborative Research Project (NSFC)
Structural Seismic Process Simulation and Control under Multiple Ground Motions
2013-2017
3 million RMB
2. Project Objective
Theoretical Analysis
Model Experiment
Numerical Simulation
Multi-Ground Motion
Concrete Materials
Concrete Members
Concrete Structures
Multi-dimensional Ground Motion Excitations
Mechanism of damage and collapse of structures
Practical Seismic Design Measures
Structural Damage Control Techniques
Nonlinear seismic response of spacial structures
Methods Subjects Objectives
3. Research PlanA: Multi-dimensional earthquake excitation modelB: Experiments and simulation of the damage process of concrete members
C: Collapse process simulation of concrete structures
D: Theory and methods for structural disaster damage process control
3. Research Plan A-1: Multi-dimensional earthquake
excitation model in time domain (body wave and surface wave)
A-2: Relevance of Multi-dimensional earthquake excitations
A-3: Stochastical model of multi-dimensional earthquake excitation
A-4: Experimental verification of torsional components of earthquakes
A: Multi-dimensional earthquake excitation modelB: Experiments and simulation of the damage process of concrete members
C: Collapse process simulation of concrete structures
D: Theory and methods for structural disaster damage process control
3. Research Plan
B-1: Multi-axial damage experiments of concrete members (beams, columns, walls and joints)
B-2: Damage principle and restoring force model of concrete members
B-3: Damage evolution Simulation of concrete members (FEM)
A: Multi-dimensional earthquake excitation modelB: Experiments and simulation of the damage process of concrete members
C: Collapse process simulation of concrete structures
D: Theory and methods for structural disaster damage process control
3. Research Plan
C-1: Shaking table test of concrete structures
C-2: Collapse analysis of concrete structures
C-3: Multi-scale analysis of concrete structures
C-4: Seismic Design Measures
A: Multi-dimensional earthquake excitation modelB: Experiments and simulation of the damage process of concrete members
C: Collapse process simulation of concrete structuresD: Theory and methods for structural disaster damage process control
3. Research Plan
D-1: Shape memory alloy (SMA) dampers
D-2: Semi-active piezoelectric friction damper
D-3: Optimization of dampers
D-4: Active and Semi-active Control theory
A: Multi-dimensional earthquake excitation modelB: Experiments and simulation of the damage process of concrete members
C: Collapse process simulation of concrete structures
D: Theories and methods for structural disaster damage process control
3. Research PlanContents 2013 2014 2015 2016 2017
A: Multi-dimensional earthquake excitation model
A-1
A-2
A-3
A-4
B: Experiments and simulation of the damage process of concrete members
B-1
B-2
B-3
C: Collapse process simulation of concrete structures
C-1
C-2
C-3
C-4
D: Theory and methods for structural disaster damage process control
D-1
D-2
D-3
D-4
3. Research PlanDalian University
of Technology (DUT), China
Rice University (RU), USA
Phone Email Video
conference
Except the communication by phone, email or video meeting, seminars will be held between DUT and RU in China or USA.
3. Research Plan
1. Last December, we had a seminar and discuss our collaboration plan and methodologies at DUT.
2. This August, we discussed the seismic protection research plan and exchange students and scholars in RU.
Seminar on August 5,13, RU
Seminar on Sept 12,12, DUT
Seminar on Sept 12,12, DUT
4. Research Advances
SH wave incidence
1. Mathematical model of torsional component of earthquakes
0 0sin sin1
2 2 2z
v vi v
x t
0 0sin sin
2y
w wi w
x t
1
yR R
i viaw w
v v t
1 1 1 1
2 2 2 2
zL R
v i viav v
x v v t
0 0sin sin
2y
w wi w
x t
P wave
incidence
SV wave incidence
Rayleigh wave incidence
Love wave incidence
Theoretical formulation of torsional motions
4. Research Advances1. Mathematical model of torsional
component of earthquakes
0 5 10 15 20 25
-0.006
-0.004
-0.002
0.000
0.002
0.004
0.006
rocking component
rock
ing
acce
lera
tion£
¨rad
/s2 )
time£¨Sec.£©
-0.004
-0.003
-0.002
-0.001
0.000
0.001
0.002
0.003
0.004
0 5 10 15 20 25
torsional component
time(Sec.)
tors
iona
l acc
eler
atio
n£¨R
ad/s
2 £©
0.00000
0.00001
0.00002
0.00003
0.00004
0.00005
0.00006
0.00007
0.00008
0 5 10 15 20 25
rocking component
frequency£¨Hz£©
rock
ing
acc
wle
ratio
n sp
ectr
um
0.000000
0.000005
0.000010
0.000015
0.000020
0.000025
0.000030
0.000035
0 5 10 15 20 25
torsional component
frequency£¨Hz£©
tors
iona
l acc
eler
atio
n sp
ectr
um
Rocking component
Time History
Torsional component
Power Spectrum
Time History Power Spectrum
Time history of torsional motions by the proposed theory
4. Research Advances1. Mathematical model of torsional
component of earthquakes
Underground explosion to get the torsional ground motion
4. Research Advances1. Mathematical model of torsional
component of earthquakes
Underground explosion to get the torsional ground motion
场地速度剖面
两点差分法 弹性理论法Experiment Theory
0
2
4
6
8
10
12
14
16
18
20
0 200 400 600 800(m/ s)波速
(m)
深度
SP
Wave Velocity (m/s)
Profile of wave velocity
Time history of torsional acceleration
4. Research Advances2. Mathematical model of torsional
component of earthquakes
Advanced triaxial testing machine
4. Research Advances2. Damage process of concrete members
Experimentally studied the influence of loading rate on the characteristics of columns (45 columns)
Considered parameters: Strength of concrete and steel bar, shear-span ratio, loading rate and loading mode.
4. Research Advances2. Damage process of concrete members: results
0
0. 5
1
1. 5
2
2. 5
3
3. 5
4
4. 5
5
0 5 10 15 20 25 30
周数
刚度
退化
系数
慢速加载快速加载
Cycles
Static load
Dynamic load
(2) Dynamic load can result in larger degradation of stiffness
(1) Dynamic load can increase the bearing capacity of concrete members
4. Research Advances2. Damage process of concrete membersThe crack numbers of dynamic loading are less than those of static loading when the specimens are damaged with seismic loading rates.
Static load Dynamic load
4. Research Advances
3. Robust Control of Civil Structures
Nominal System Uncertain System
Steel columns
Uncertainties
4. Research Advances
3. Robust Control of Civil Structures
Model analysis and updating to make sure the norm upper limit for the uncertainties
0 0.005 0.01 0.015 0.02 0.025 0.030
1
2
Drift (m)
Sto
ry
Peak Inter-story Drifts
Case1Case2Case3Case4Case5
0 0.002 0.004 0.006 0.008 0.010
1
2
Drift (m)
Sto
ry
RMS Inter-story Drifts
Case1Case2Case3Case4Case5
4. Research Advances
Case number Controller Structure
1 TMD Without uncertainties
2 H∞ controller Based on nominal system Without uncertainties
3 TMD With uncertainties
4 H∞ controller Based on nominal system With uncertainties
5 D-K controller Considering the uncertainties With uncertainties
0 2 4 6 8 10 12-0.01
-0.005
0
0.005
0.01
Time (s)
Dri
ft (
m)
Inter-story Drift Time History at Floor-2
Case 4Case 5
0 2 4 6 8 10 12-0.02
-0.01
0
0.01
0.02
Time (s)
Dri
ft (
m)
Inter-story Drift Time History at Floor-1
Case 4Case 5
4. Research Advances
3. Robust Control of Civil Structures