거더 구조물의 진동-임피던스 기반 하이브리드 구조건전성 모니터링 및 온도영향 평가

Abstract

In this study, temperature-compensated hybrid structural health monitoring (SHM) scheme of girder's structures is proposed. In order to achieve the objective, the following approaches are implemented. Firstly, vibration- and impedance-based SHM methods are determined for hybrid SHM scheme. The structure and damage types are determined for application of the SHM methods. Prestressed concrete (PSC) girder and steel girder are selected as the target structures of girder's structures. The damage types of PSC girder are selected as stiffness-loss in girder and prestress-loss in tendon. Steel girder is selected damage in bolt connection. Also, the vibration-based SHM methods are performed for global damage alarming and damage estimation. The impedance-based SHM methods are performed for local damage alarming and damage classification. Secondly, the temperature compensation methods are presented to improve hybrid SHM scheme. The linear regression analysis and effective frequency shift (EFS) methods are selected as the temperature compensation. The temperature-compensated hybrid SHM scheme is accomplished after temperature effect estimation. Thirdly, the feasibility of the temperature-compensated vibration- and impedance-based SHM techniques are evaluated in lab-scaled PSC girder for which several damage scenarios are experimentally examined with acceleration and impedance response features. The stiffness loss and prestress loss of PSC girder are estimated with temperature-compensated vibration- and impedance-based SHM algorithm. The temperature-compensated vibration SHM algorithm are performed damage alarming and damage estimation for damage types of the target structures. The temperature-compensated impedance-based SHM algorithm are performed damage alarming and damage classification. Finally, the feasibility of the temperature-compensated hybrid SHM scheme of steel girder is evaluated for which several damage scenarios are experimentally examined with acceleration and impedance response features. The bolt connection damage as stiffness-loss of steel girder are estimated with temperature-compensated SHM algorithm. The selected temperature- compensated vibration SHM algorithm are performed damage alarming and damage estimation for stiffness-loss of steel girder. The selected temperature-compensated impedance-based SHM algorithm is performed damage alarming and classification.