The research objectives of this award are to 1) develop and calibrate new fiber optic sensors that are fireproof and sensitive to temperature and strain, 2) develop an integrated sensing system and a decision-making tool based on measured strains and temperatures, and 3) validate and demonstrate the developed system in a high-temperature environment for the assessment of the progressive collapse mechanism of steel structures. Building frame models, representing a reduced-scale substructure of the 3-story steel building frame used in SAC Steel Project after the 1994 Northridge earthquake, will be tested under gravity loads at elevated temperatures. To simulate various earthquake effects, the frames will be first subjected to different inelastic stresses with a lateral load. It will then be tested at elevated temperature. As the temperature increases, the steel column degrades (softens) and its ability to carry the dead weights decreases gradually. The progressive collapse of the frame will be monitored with fire-resistant sensors and predicted in real time using the finite element model updating technique.
This award results from a collaborative effort of faculty from electrical and civil engineering, thus providing an interdisciplinary training opportunity to participating students in structural health monitoring and condition assessment. If successful, the new sensor technology will enable researchers to measure data at fire-structure interfaces that are critical to fundamental understanding of the fire-induced structural degradation process in post-earthquake fire environments. The developed decision-making tool with FEM will allow a real-time monitoring and assessment of the structural condition of steel buildings in post-earthquake fire environments. Research findings will be integrated into the teaching of an undergraduate senior course that will attract students from a broad range of backgrounds including electrical, civil, and mechanical engineering. The enabling technology will be demonstrated to federal agencies such as FEMA for potential deployment in future disaster responses.
