Laboratory experiment of the structural sensing method using the accurate artificial vibrator

摘要

This paper presents a structural sensing method using the accurate artificial vibrator and shows the results of vibration experiments in laboratory scale. The accurate artificial vibrator generates harmonic forces by rotating an eccentric mass. Since the rotation is accurately controlled by means of a phase control type servomotor, the vibrator generates accurate harmonic forces periodically. The phase information obtained from the servomotor let us calculate the force function precisely. Applying Auto-Regressive exogenous (ARX) model to the time series of force function and measured displacement responses yields the Green function of a target structure. In this research, we investigated the performance of prototype system and developed the Green function estimation method. We also conducted laboratory scale vibration tests in which the prototype system was applied to a two-meter simple beam. The estimated Green function was simulated by the analysis of Finite Element Method (FEM) and its structural model was successfully determined.