하이브리드 구조건전성 모니터링에 의한 강판형 거더교의 손상검색에 관한 연구

Abstract

Major damage-types of steel plate girder bridges include flexural crack and support failure. Over the past two decades, many researchers have attempted to detect the damages in various-type bridges by using changes of vibration and impedance characteristics. However, the following problems still remain to be solved for successful damage detection in steel plate girder bridges: (1) the damage types of steel plate girder bridges cannot be easily recognized from he vibration-based techniques, (2) the impedance-based techniques should need too many sensors (i.e., PZT sensors) for damage detection in the entire structure. In order to overcome these problems, a hybrid health monitoring scheme that can alarm damage occurrence, classify damage-types, and identify damage locations and severities in steel plate girder bridges by using acceleration sensors and PZT sensors is proposed. In order to achieve the objective, the following approaches are implemented. Firstly, a hybrid damage monitoring scheme for steel plate girder bridges is newly designed. Secondly, damage monitoring techniques are selected for the hybrid damage monitoring. Thirdly, the numerical test is performed to select most suitable number of acceleration sensor for third step in hybrid monitoring scheme. Finally, the feasibility and practicality of the proposed damage monitoring scheme are evaluated from laboratory testes on model plate girder bridges for which acceleration responses were measured for several damage cases such as flexural crack and support damages.