World Forum on Smart Materials and Smart Structures Technology �Spencer et al. (eds) 2008 Taylor & Francis Group, London, ISBN 978-0-415-46845-9Structural health monitoring on damage evolution of 6 story reinforced building through shaking table testKoichi MoritaBuilding Research Institute, Tsukuba, JapanTaizo MatsumoriNational Research Institute for Earth Science and Disaster Prevention, Miki, Japan1INTRODUCTION4RESULTS OF IDENTIFICATIONIn this paper, damage estimation on damage evolution of 6 story reinforced building is shown through shaking table test. Using the system identification technique, natural frequency and damping ratio, story stiffness of damaging reinforced concrete construction test specimen are carried out, and the change of these characteristics in the damage evolution is examined. Correspondence between identification results and visual inspection & analysis is examined, and the method for estimating the damage state of the building will be proposed.2DESCRIPTION OF TEST FRAME AND EXPERIMENTSFrom the results of (a), natural frequency and story stiffness decreases and damping ratio increases as amplitude increases, and natural frequency and story stiffness tend to be smaller and damping ratio tends to be larger during principal motion. Tendency of identified story stiffness from (b) is consistent with visual inspection. Minimum identified stiffness from (a) agrees with the results from push over analysis. Identified stiffness from white noise shaking which is carried out just after earthquake shaking is three times larger than minimum identified stiffness from (a). By using the assumption of Takeda-model, maximum displacement estimation from white noise shaking data is tried. 5 CONCLUDING REMARKSThe test frame floor height is 1 m, total height is 6 m, floor plan is 6 m 4 m and there are three spans in excitation direction. Shaking table test is carried out at one direction large-scale earthquake simulator facility of the National Research Institute for Earth Science and Disaster Prevention. We carry out damage detection test by damaging the frame and we measure the evolution of damaging frame.Results obtained from this experiment can be summarized as follows. 1) Tendency of story stiffness before and after the seismic shaking agreed with tendency by the visual inspection just after the shaking. 2) Story stiffness after the seismic shaking is very different from story stiffness under seismic shaking. 3) Smallest story stiffness under seismic shaking agreed with the story stiffness from the static push-over analysis. Estimation of the maximum drift using the data of white noise shaking after earthquake shaking is examined. Estimation is difficult in this state, but it is shown to be possible by using storage of the static member test data.3DATA FOR IDENTIFICAIOTN AND IDENTIFICATION METHODTwo types of identification are tried. One is (a) identification using the data during damage evolution and the other is (b) identification using the data of before and after damage. In both cases, we use identification method by ARX (Auto Regressive eXogenous) model. The ARX model structure is the simple linear difference equation161
