| Internet technology enables earthquake engineering researchers to carry out networked collaborative testing by linking remote structural laboratories and realizing data transmission and remote control. Through Internet, several laboratories can be integrated into one powerful networked testing system to complete some large-scale structural testing with complexity models or the testing of actual structures. This enhances testing capability and makes it possible to share resources. Several attempts have been made to carry out collaborative testing of large-scale structural models with remotely distributed laboratories.Based on the exsiting testing equipments and calculation resource in laboratory, the remote collaborative testing system is set up in this paper. The first international collaborative pseudo-dynamic testing in civil engineering is carried out in mainland China. Several pseudo-dynamic testing methods and technologies are also studied during the process. The main research contents are described as following:1. Through comparing with NEES (Network for Earthquake Engineering Simulation) in America and ISEE in Taiwan, the main components of remote collaborative testing system are investigated, including the network protocol, the testing equipment and control system and the calculation analysis system, and the integrating method and technology of these components. Based on these studies, the setup method of remote testing system in this paper is investigated. Several virtual testing and public testing on Internet with remote distributed sites are carried out under different network environment using NetSLab (Networked Structural Laboratories) network protocol developed by a research group lead by the Hunan University. The results show that NetSLab network protocol can communicate smoothly on Internet, achieves its function, and provides the supporting of network technology.2. Aming at MTS system widely used in civil engineering testing, the testing equipment and control system of remote collaborative testing system is investigated. Based on the serial software of MTS 793 and the hardware resource of FlexTest GT control system, two kind of pseudo-dynamic testing method and technology are investigated. The pseudo-dynamic testing system based on calculation command control is set up. The pseudo-dynamic testing about steel member is carried out to validate the feasibility of the testing system. The results show that the testing system can achieve real-time testing, and provide a good research platform of seismic testing for those structural members related with velocity.In order to set up the pseudo-dynamic testing system suitable for any control system of testing equipment, the external command control metod is put forward. The pseudo-dynamic testing system is set up by hybrid program control with Visual C++ and MATLAB. The pseudo-dynamic testing of three DOF and substructural pseudo-dynamic testing of six DOF about a full-scale masonry structure are carried out. The results show that the hardware connection of external command control only has relation with the input and output channels of control system of testing equipment, and the program control is also unrelated with control software. Compared with other pseudo-dynamic testing methods such as calculation command control, its application is independent with any control system and has universal property. The testing system combines the powerful function of Visual C++ with flexible calculation program of MATLAB. The control program developed by Visual C++ can enable several actuators to load effectively and accurately but not couple with each other at one time. MATLAB program enables the calculation program to be compiled and extanded easily.These two methods both present an idea of structural seismic hybrid testing integrating numerical simulation and physical testing.3. In order to integrate the network protocol, testing equipment and control system and calculation analysis system into the whole body, and set up the remote collaborative testing system, the method of hardware connection and software program is used to integrate the components of testing system together by applying the external command control and program control method with ActiveX technology, and combining the application program interface of NetSLab network protocol. The actual tester program suitable for any control system of testing equipment is compiled. The stable and accurate control method for fast load is also investigated.Using the testing system, the collaborative pseudo-dynamic testing on LAN (Local Area Network) is carried out about a cantilever steel beam. In order to carry out fast testing, a kind of numerical integration method suitable for real-time or fast pseudo-dynamic testing, momentum equation is investigated. The explicit displacement expression is obtained by solving implicit equation with explicitγ-function. A kind of external displacement control method based on hardware control is used put forward. The results show that the testing system can achieve the requirements of the integration and collaborative control of every component, and can be extanded across the Internet as a fundamental platform. The availability of the integration method is also proved. The testing process shows that although the external displacement control method has some risk and higher hardware requirements for testing control system, the proporiate control parameter can be found out to ensure the fast response of the actuator. It provides a good control method for fast pseudo-dynamic testing research.4. The reinforced concrete bridge short column model of remote collaborative testing is designed and manufactured. The quasi-static testing is carried out about the column model with no restraint and strong restrained by three layers of CFRP (Carbon Fiber Reinforced Plastic). Using the integrated testing system, the pseudo-dynamic testing is carried out about a column model restrained by CFRP at the stage of elastic behavior, plastic partial damage and post partial damage through assuming the column model fixed at both sides as a single DOF system. The results show that the assumption of column model is reasonable; it has stable 2nd order degradation stiffness at the range of some displacement, and the stiffness falls to be 1/3 of the initial value, which has consistence with the results from quasi-static testing. This work further proves the design of model, and provides the restoring force model. The remote collaborative testing system is also validated.5. The first Internet-based collaborative pseudo-dynamic testing in mainland China is carried out by the collaboration of Hunan University (HNU) as leader, Harbin Institute of Technology (HIT) and Tsinghua University in mainland China, and the University of Southern California in America. Several key technologies are investigated including testing model, testing equipment and control system, the integration of the networked testing system and the process of collaborative testing. The Russion River Bridge at Southern California in America is used as the prototype. Every pier of the bridge is divided as a substructure. Different testing equipments are used to simulate the different boundary conditions at HNU and HIT laboratories, respectively. Two approaches are used to achieve the communication between the network protocol and the testing equipment at HNU and HIT laboratories. The substructural numerical simulation is carried out at other laboratories. The whole testing is orginazated and coordinated by the controller at HNU. The results show that the networked collaborative testing system with powerful capability provides a testing platform with good coordination for complex models or actual structures, and achieves remote sharing of testing equipments.
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