Structural health monitoring of wooden structures by using subspace system identification based on shaking table tests

To evaluate the earthquake resistance of wooden structures, a structural health monitoring method based on subspace system identification was applied to acceleration data obtained from full-scaled shaking table tests of wooden post and beam structures made with plywood and brace. The ordinary Multi-variable Output-Error State sPace (MOESP) was used to evaluate the temporal variation of the natural frequency of the structure. As a result, the identified equivalent story stiffness was higher than the secant stiffness evaluated by the hysteresis loop of the specimen. This suggests that the subspace method might underestimate the structural damage.