ISEE: Internet-based Simulation for Earthquake Engineering

Part (I): The Database Approach

Yuan-Sen YANG, Shiang-Jung WANG,

Kung-Juin WANG, Keh-Chyuan TSAI and Shang-Hsien HSIEH

Joint NCREE/JRC Workshop Int’l Collaboration on Earthquake Disaster mitigation Research, Nov. 17-18, 2003

Related Research Work• Japan-Korea research

– Networked real experiment in Japan (1998)– Networked simulated test in Korea (2000)– Networked simulated test between Japan and Korea

(2001)– ED-net in E-Defense (Japan) (to be completed by 2005)

• NEES project in US– 15 experiment sites with high performance Internet– To integrate experimentation, computation, theory,

databases, and model-based simulation– To be completed by Sep., 2004.

Laboratories in Taiwan• Present:

– Earthquake engineering laboratories distribute in Taiwan

– Laboratories have

diverse characteristics

• Future challenge:– Collaborative

experiments

– Resource sharing

NCREE

NTU NTUST

NCU

NCHU

NCKU

NKFUST

NCTU

NCNU

ISEE Today• Database Approach

– Communicating by SQL commands

FCM #1 FCM #2

ServerCGM

Camera Camera

PNSEcommandsresponses

Video server Video server Web server Database

Experimental data

Viewer #1 Viewer #2

FCM #1 FCM #2

ServerCGM

Camera Camera

PNSEcommandsresponses

Video server Video server Web server Database

Experimental data

Viewer #1 Viewer #2

FCM #1 FCM #2

ServerCGM

Camera Camera

PNSEcommandsresponses

Video server Video server Web server Database

Experimental data

Viewer #1 Viewer #2

FCM #1 FCM #2

ServerCGM

Camera Camera

PNSEcommandsresponses

Video server Video server Web server Database

Experimental data

Viewer #1 Viewer #2

• Application Protocol Approach– Communicating by

TCP/IP commands

Overview of Database Approach

Data Center

• Data Center– A Database server

• Microsoft SQL Server

– A WWW interface

• Microsoft IIS

– A C++ class to communicate with Data Center

• For the Facility Controllers and Analysis Engine to access data in the Data Center through Internet.

• Tested on MS Visual C++ 6.0

Analysis Engine• Analysis Engine

– OpenSees

• a finite element program developed by PEER, USA (http://opensees.berkeley.edu/ )

– A user-defined element type

• With user-defined initial stiffness, damping, and mass matrices of the specimen.

• Communicates the experiment-analysis interaction data between OpenSees and Data Center

Facility Controllers

• Facility Controller– A C++ program accessing the

Data Center and controlling the facilities

• Developed Facility Controllers– NCREE actuator controller

• MTS Flex Test IIm controller

– NTU actuator controller• MTS 407 controller

• Other Facility Controllers– Different controllers in different l

aboratoriesNCREE actuator controller

Three-Layer Concept

• Three-layer concept

WWWBrowser

UserLayer

MiddleLayer

DataLayer

WWWServer

Database

AnalysisEngine

FacilityController

Access Interface

Network Fault Tolerance

Facility Controller

Analysis Engine

Workstation

Data Center

Experiment time

Restart output file

Network message passing File I/O

Network disconnection!

Step1 ... Step(i-1) Step i

Facility Controller

Analysis Engine

Workstation

Data Center

Experiment time

Restart output file

Network message passing File I/O

Step1 ... Step(i-1) Step i

Previousrestart file

A BRB Frame Test (1/2)• A steel Buckling-Restrained-Brace frame (BRB)

BRB frame at NCREE

Data Viewers

Data Center

BRB Frame Facility Controller

Analysis Engine

Numerical model

Network configuration of BRB test

A BRB Frame Test (2/2)

• A substructure pseudo-dynamic test– Data Center: NCREE– Facility Controller: NCREE– Analysis Engine: Stanford Univ.

– # of time steps: 2000 (10 sec.)– Total experiment time: 46 min 4

sec. (1.4 sec per time step) • Nearly 70% for network and

database • Nearly 30% for facility

controlling

Elapsed Time (each step) (sec.)

0.0

2.0

4.0

6.0

8.0

Time Step

Elapsed Time (each step) (sec.)

0.0

2.0

4.0

6.0

8.0

Time Step

DSCFT Experiment (1/2)

NTU Lab. NCREE Lab.

Analysis EngineData Center

Concrete infilled

Double tubeBi-axial controlled

DSCFT column

Analysis model of a 4-pier bridge

C1 C2 C3 C4

B1 B2 B3

6m2m 2m

2.37m2.

37m

Real DSCFT specimenNumerical simulated component

NTU Lab. NCREE Lab.

Analysis EngineData Center

DSCFT Experiment (2/2)

At NCREE Lab. At NTU Lab.

RCS Frame Experiment

• The RCS experiment– A single-site experiment

– Data sharing via WWW

• Real-time data plot

• Real-time video

Network configuration of RCS test

Real-time video image

Real-time data plot

(Available at http://RCS.ncree.gov.tw)

ISEE: Future• Basic components

Analysis

ISEE: Future

Security

Database

Video stream

Visualization

Message board/Messenger

File transferring

(Compound images)

ISEE: Future

• ISEE Grid NCREE

NTU NTUST

NCU

NCHU

NCKU

NKFUST

NCTU

NCNU

Analysis

International EE Network• International Collaborations

Conclusions

• ISEE: A prototype of an Internet-based environment is developed for collaborative networked pseudo-dynamic tests.

• Reasonable elapsed time of networked pseudo-dynamic tests among laboratories at different locations.

• Several tests present the feasibility of transnational collaborative experiments.

• Future ISEE needs more efforts and cooperation.