Report - PEER - University of California, Berkeley

:::::2004) can be formulated using system transition matrices derived from exactsolutions. Such solutions are exact for elastic structures and present minimal errorsfor inelastic structures (Chu et al., 2002). Most recently analytical techniques basedon Hamiltonian-Lagrangian formulations (Sivaselvan and Reinhorn, 2004) provedthat inelastic problems with severe degradation, sudden breaks and repetitive impacts,as well as progressively collapsing structural assemblies can be solved with stablesolutions using energy minimization techniques. These techniques and othersdeveloped in recent years still need experimental verification and identification ofunknown phenomena neglected in modeling.3. SUBSTRUCTURE TESTING OF LARGE SPECIMENSSeveral experimental procedures are used to simulate and test the behavior ofstructural systems and components under earthquake loads. These include (1) Quasistatictesting (2) Shake-table testing (3) Effective force testing (4) Pseudo-dynamictesting and (5) Real Time Dynamic Hybrid testing (this paper). The Real-TimeDynamic Hybrid simulation, a form of substructure testing technique, allows onlyparts of the structure for which the analytical understanding is incomplete to be testedexperimentally.m 5x 5am 4x 4am 3x 3aFiF im 2x 2a(a)m 1x 1a(b)F 2F 1(c)Figure 2. Modern methods for “dynamic” testing (a) effective force (b) pseudodynamic(c) real-time dynamic.But in contrast to other existing testing methods, the last testing method allowssubstructures to be tested in the context of structural assemblies under dynamicconditions so that they can be subject to realistic load histories. The real-time testingallows the rate-dependent effects to be captured accurately. Moreover when the realtime evaluation of the structure is combined with real time identification of propertiesthe resulting computational system becomes a reliable tool for analytical studies.The substructure testing was developed in the ’80s and formulated by numerousresearchers (Nakashima 1985, Mahin et al. 1985, Shing et al., 1985). As a traditionalform of substructure testing technique, the pseudo dynamic test is an experimentaltechnique for simulating the earthquake response of structures and structuralcomponents in the time domain. The test was developed in the early 1970s, having a261