Design and evaluation of passive and active structural health monitoring systems for bridges and buildings

摘要

Abstract: Structural health monitoring systems have been designed and evaluated in the laboratory for installation in several bridges and commercial buildings. The systems employ solid-state sensor elements which experience a strain-dependent phase transformation from a metastable, nonmagnetic, austenitic phase to the stable, ferromagnetic, martensitic phase. The irreversible phase transformation is useful for indicating the level of peak structural strain experienced in a particular monitored location. Some of the sensor material characteristics and details related to the phase transformation are discussed as applied to structural health monitoring. The design of representative systems for bridges and commercial buildings is included. Important system(s) features and design capabilities are discussed. Finally, the evaluation of passive and active systems in the laboratory is discussed. The results of experiments detailing the behavior of these systems under uniaxial tension and cyclic loading conditions are presented. !12