Measurement of relative story displacements by noncontact-type sensors on forced vibration test of an actual building

This study presents the practical assessment of a relative story displacement sensing system verified through the forced vibration test on an actual three-story building. In the sensing system, we apply two noncontact-type sensors utilizing position sensitive detectors (PSDs) and phototransistor arrays (PTrs). They are installed between each adjacent pair of floors, and they can directly measure the relative story displacements. The basic features and their applicability are discussed by analyzing the measurement records from sensors. The results show the effectiveness of the sensing system under realistic conditions, and clarify the issues to be improved in its applications to the structural health monitoring system.