Project: Structural Seismic Process Simulation and Control under Multiple Ground Motions PI: Prof. Hongnan Li Dalian University of Technology, China Co-PI

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

Outline

3. Project Contents

2. Project Objective

4. Research Advances

1. Background

Outline

3. Research Plan



1. Background

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


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


Yushu Earthquake (Ms 7.1)

Time ： 07:49, April 14, 2010

Location ： Yushu County, Qinghai

Province in China

Dead People: 2698



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



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

Outline


3. Research Plan


1. Background


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

Outline

3. Research Plan



1. Background

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



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)




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


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



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-1

C-2

C-3

C-4


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

Outline


3. Research Plan


1. Background


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



Underground explosion to get the torsional ground motion



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



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


3. Robust Control of Civil Structures

Nominal System Uncertain System

Steel columns

Uncertainties



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


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



Thanks for your attention!Thanks for your attention!

August 8, 2013August 8, 2013

Documents

Project: Structural Seismic Process Simulation and Control under Multiple Ground Motions PI: Prof. Hongnan Li Dalian University of Technology, China Co-PI