Civil, Environmental and Architectural Engineering

NSF Grant to Boost Earthquake Engineering Research, continued

While model-based simulation has been used as a predominant tool in the design of mechanical systems and aerospace structures, its usage in the earthquake design of civil structures is still very limited. This is because buildings and bridges are expected to develop significant inelastic behavior in the event of a major earthquake. The inelastic behavior of structural components, connections, and materials is extremely complex, and most mathematical models are not able to capture all the essential details to assure a realistic assessment. The Fast Hybrid Test method combines model-based simulation and physical testing in an optimal manner so that parts of a structure can be modeled analytically, while other parts that are expected to experience significant damage are tested experimentally. The physical and analytical substructures are linked by a computer model that represents the entire structure.

The new equipment can be efficiently used to test shear walls, for example. Shear walls are often the main seismic load-resisting elements in a reinforced concrete building. The testing of an entire multi-story building is often unfeasible because of the costs and the lack of large-scale experimental facilities. With the Fast Hybrid Test System, we can test only the bottom story wall where most of the damage is expected to concentrate and model the rest of the building in a computer.

The equipment at the University of Colorado will be operational by September 2004. It will be linked to the research community via the Internet using Gigabit Ethernet connections to allow teleobservation and teleoperation by researchers at other locations. This will be a main feature of all NEES equipment sites. Furthermore, with the Internet connection, the Fast Hybrid Test method can be used to conduct linked tests at different geographic locations. This will revolutionize the way experimental research is conducted and open unlimited opportunities for national and international cooperation on structural testing.