Report - PEER - University of California, Berkeley

history of nearly thirty years. In this test, the structural system is represented as adiscrete spring-mass system, and its dynamic response to earthquakes is solvednumerically using direct integration. Unlike conventional direct integrationalgorithms, in the pseudo dynamic test the restoring forces of the system are notmodeled but are directly measured from a test conducted in parallel.Because of various advantages of this test over the shaking table test, which isknown to be the most direct method to simulate the earthquake responses ofstructures, the test has been introduced in many research institutions throughout theworld. As an extension of this testing technique, the pseudo dynamic test with a realtimecontrol was developed in the 1990s. A few of the notable developments arepresented in Nakashima et al. (2003).Real-time dynamic hybrid testing, the main subject of this paper, extends theabove testing techniques by allowing for testing substructures under realistic dynamicloads and for representing rate-dependent and distributed inertia effects accurately.While the fast pseudo-dynamic (mentioned above) and the real-time dynamic hybridtesting use substructures for physical testing and online computations to simulate theglobal system in real-time, the latter technique includes the inertia effects are part ofthe physical system testing.The newly developed George E Brown Network for Earthquake EngineeringSimulation, developed experimental and computational infrastructure forimplementation of Pseudo-Dynamic Testing (University of Illinois, LehighUniversity), Fast Pseudo-Dynamic Testing (University of Colorado, University ofCalifornia at Berkeley, Univeristy at Buffalo) and the most advanced Real-TimeDynamic Hybrid Testing (University at Buffalo). Description of those installationscan be found at http://www.nees.org/.4. FORMULATION OF NEW HYBRID TESTING TECHNIQUEOptionalOptionalComputational SubstructurePhysicalSubstructurComputational SubstructurePhysicalSubstructurShake TableStructuralActuatorMTS ActuatorController (STS)MTS Hydraulic PowerController (HPC)SCRAMNET INetwork SimulatorCompensation Controller Real-time SimulatorxPC TargetGeneral PurposeData AcquisitionSystemData AcquisitionGround/Shake TableSCRAMNET IIMTS Shake TableController (469D)Hybrid TestingCONTROL OFLOADING SYSTEMHYBRID CONTROLLERUB-NEES NODEFigure 3. Schematic of real-time dynamic hybrid test system.Real-time Dynamic Hybrid Testing (RTDHT) shown in Figure 2(c) is a novelstructural testing method involving the combined use of shake tables, actuators, andcomputational engines for the seismic simulation of structures.262