Prestress-Loss Monitoring Technique for Prestressd Concrete Girders using Vibration-based System Identification

J. Ocean Eng. Technol. 2010;24(1):123-132.

Ho Duc-Duy,Hong Dong-Soo,Kim Jeong-Tae

Smart Structure Engineering Laboratory Ocean Engineering Pukyong National University,Smart Structure Engineering Laboratory Ocean Engineering Pukyong National University,Smart Structure Engineering Laboratory Ocean Engineering Pukyong National Unive

진동기반 구조식별을 통한 프리스트레스트 콘크리트 거더의 긴장력 손실 검색 기법

호득유이,홍동수,김정태

부경대학교 해양공학과 스마트구조공학연구실,부경대학교 해양공학과 스마트구조공학연구실,부경대학교 해양공학과 스마트구조공학연구실

Keywords: Prestressd concrete girder, Prestress force, Finite element model, Prestress loss prediction, Natural frequency, System identification

핵심용어: 프리스트레스트 콘크리트 거더, 긴장력, 유한요소모델, 긴장력손실 예측, 고유진동수, 구조식별

Abstract

This paper presents a prestress-loss monitoring technique for prestressed concrete (PSC) girder structures that uses a vibration-based system identification method. First, the theoretical backgrounds of the prestress-loss monitoring technique and the system identification technique are presented. Second, vibration tests are performed on a lab-scaled PSC girder for which the modal parameter was measured for several prestress-force cases. A numerical modal analysis is performed by using an initial finite element (FE) model from the geometric, material, and boundary conditions of the lab-scaled PSC girder. Third, a vibration-based system identification is performed to update the FE model by identifying structural parameters since the natural frequency of the FE model became identical to the experimental results. Finally, the feasibility of the prestress-loss monitoring technique is evaluated for the PSC girder model by using the experimentally measured natural frequency and numerically identified natural frequency for several prestress-force cases.