Vibration-Based Damage Monitoring in Model Plate-Girder Bridges under Uncertain Temperature Conditions

J. Ocean Eng. Technol. 2008;22(1):75-82.

Park Jae-Hyung,Hong Dong-Soo,Cho Hyun-Man,Kim Jeong-Tae

Department of Ocean Engineering Pukyong National University,Department of Ocean Engineering Pukyong National University,Department of Ocean Engineering Pukyong National University,Department of Ocean Engineering Pukyong National University

불확실한 온도 조건하의 모형 강 판형교의 진동기반 손상 모니터링

박재형,홍동수,조현만,김정태

부경대학교 해양공학과,부경대학교 해양공학과,부경대학교 해양공학과,부경대학교 해양공학과

Keywords: Plate-girder bridges, Temperature effect, Vibration-based, Natural frequency, Damage monitoring

핵심용어: 판형교, 온도영향, 진동기반, 고유진동수, 손상모니터링

Abstract

A vibration-based damage-monitoring scheme is proposed that would generate an alarm showing the occurrence and location of damage under temperature-induced uncertainty conditions. Experiments on a model plate-girder bridge are described, for which a set of modal parameters was measured under uncertain temperature conditions. A damage-alarming model is formulated to statistically identify the occurrence of damage by recognizing the patterns of damage-driven changes in the natural frequencies of the test structure and by distinguishing temperature-induced off-limits. A damage index method based on the concept of modal strain energy is implemented in the test structure to predict the location of damage. In order to adjust for the temperature-induced changes in the natural frequencies that are used for damage detection, a set of empirical frequency correction formulas is analyzed from the relationship between the temperature and frequency ratio.