NetSLab Based Remote Hybrid Testing in AHierarchical Network Environment

Yu-rong Guo1, Yan Xiao2 and Qing Hu3

Fourth NEES Annual Meeting Washington DC June 21-23, 2006

1. Hunan University, China

2. University of Southern California

3. FutureNet Corporation, Monrovia, California

Outline

1. Intrduction2. NetSLab (Networked Structural La

boratories) development3. Application of NetSLab4. Concluding remarks

1. IntroductionCollaborative research/test

NEES (Network for Earthquake Engineering Simulation, USA)ISEE (Internet-based Simulation for Earthquake Engineering, Taiwan)E-Defence (Japan)KOCED (Korea Construction Engineering Development program, Korea)BLADE (Bristol Laboratory for Advanced Dynamic Engineering,UK) ELSA (The European Laboratory for Structural Assessment)

NetSLab (Networked Structural Laboratories)

Hunan University

Tsinghua University Harbin Institute of Technology

National Natural Science Foundation of China (NSFC)

Other institutes

Internet

Lab #1

Lab #2

Lab #3

NetSLabNetSLabCommunication platformApplication development

Hierarchical Network Environment

Internet

LAN

LANDirect point-to-point connection

Public IP

Public IP

CERNET(China Education and Research

Network)

National Network Center

Regional Network Centers

Provincial Network Centers

City Network Center

2. NetSLab (Networked Structural Laboratories ) Development

2.1 Basic Features of NetSLab

Client/Server conceptSocket based communication mechanismGeneralized data model

Testing results

Three types of participants

Communication protocols

Controller

Tester

Tester

TesterTester

Tester

Observer

ObserverObserver

Observer

Testing results

Observer

Three types of participants

Controller

Tester1 Tester2 Tester3

Controller

Tester1 Tester2 Tester3

Controller

Tester1 Tester2 Tester3

Centralized sequential communication protocol

Centralized parallel communication protocol

Distributed parallel communication protocol

Communication protocols

2.2 Implementation of NetSLab

Dynamic Unified Data Packet (DUDP)

<DUDP> <Communication> …(1)Control information </Communication> <CurTestResult> …(2)Testing data </CurTestResult></DUDP>

Generalized Data Communication Agency (GDCA)

Controller

Tester1

Tester2

GDCA

DUDP

DUDP

DUDP

GDCA

GDCA

GDCA interface: ActiveX control

GDCA: Design and maintenance

2.3 Across firewall/proxy communication

Simulation of global structure

Controller PC

Public IP

Internet

LAN

Firewall

Test of substructurePhysical Tester

LAN

Simulation of substructureVirtual Tester

Loading facilities

Private IP Private IP

Tester PC #1

Tester PC #2

Firewall

Port 80

Communication Server PC

Public IP

Internet

LAN

Firewall

Test of substructurePhysical Tester

LAN

Simulation of substructureVirtual Tester

Loading facilities

Private IP Private IP

Tester PC #1 Tester PC #2

Firewall

Port 80 Simulation of global structure

Controller PC

Private IP

LAN

3. Application of NetSLab for Remote hybrid Dynamic Testing

3.1 Testing program development

Main interface of testing program

3.2 Actual testing using NetSLab

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0. 8

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1. 2

0 100 200 300 400 500

Test step

Time

(s)

3.3 Communication efficiency

T – Average time spent on Internet communication for a round trip data transfer between two computers

T =0.025~0.03s within University of Southern California(USC)

T = 0.3s between the Hunan University (HNU) and USC

T =0.55~0.6s between HNU and Los Angeles using dialup connection

4. Concluding Remarks

A network communication platform (NetSLab) was developed for remote hybrid dynamic testing of structures, which provides relatively easier and friendlier interface for application development and across multi-level proxy and firewall communication capability.

The adequacy and efficiency of the NetSLab platform was validated by several remote virtual and actual tests at and between two universities in the US and China.

Acknowledgments

The authors would like to express their appreciations to the support of the National Natural Science Foundation of China (NSFC) under the National Key Project (Grant No. 50338020); FutureNet Technologies Corporation, Monrovia, California, USA and its China subsidiary division provided supports under an agreement for joint development, academic promotion and applications.

Hunan University

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1. 2

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Test step

Time

(s)

USC/USC/HNUHNU

00. 20. 40. 60. 8

11. 2

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Test step

Time

(s)

0. 1

0. 12

0. 14

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0. 18

0. 2

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Test step

Time

(s)

USC/Waterloo,Canada T=0.11sUSC/Waterloo,Canada T=0.11s

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0. 8

1

1. 2

0 100 200 300 400 500

Test step

Time

(s)

0. 2

0. 22

0. 24

0. 26

0. 28

0. 3

0 100 200 300 400 500

Test step

Time

(s)

USC/Shuzhou,China T=0.23sUSC/Shuzhou,China T=0.23s