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Development of a Nonlinear SI Scheme using Measured Acceleration Increment

측정 가속도 증분을 사용한 비선형 SI 기법의 개발

  • 신수봉 (인하대학교 토목공학과) ;
  • 오성호 ((주)대본엔지니어링 구조팀) ;
  • 최광규 (동아대학교 토목공학과)
  • Published : 2004.12.01

Abstract

A nonlinear time-domain system identification algorithm using measured acceleration data is developed for structural damage assessment. To take account of nonlinear behavior of structural systems, an output error between measured and computed acceleration increments has been defined and a constrained nonlinear optimization problem is solved for optimal structural parameters. The algorithm estimates time-varying properties of stiffness and damping parameters. Nonlinear response of restoring force of a structural system is recovered by using the estimated time-varying structural properties and computed displacement by Newmark-$\beta$ method. In the recovery, no pre-defined model for inelastic behavior has been assumed. In developing the algorithm, noise and incomplete measurement in space and state have been considered. To examine the developed algorithm, numerical simulation and laboratory experimental studies on a three-story shear building have been carried out.

구조물의 손상 진단을 위해 측정 가속도 데이터를 사용한 비선형 시간영역 SI 알고리듬을 개발하였다. 구조물의 비선형 거동을 고려하기 위하여 측정 가속도 증분과 해석에 의한 가속도 증분의 차이로 출력오차를 정의하고, 구속 비선형 최적화 문제를 풀어 최적 구조변수를 구하였다. 개발된 알고리듬은 시간에 따라 변하는 강성도와 감쇠 변수를 추정하도록 하였다. 구조물의 비선형 거동에 의한 복원력은 추정된 시간에 따라 변하는 구조변수와 Newmark-$\beta$법으로 계산한 변위를 사용하여 복원하였으며, 복원 과정에서 비탄성 거동에 대한 어떤 모델도 사전에 설정하지 않았다. 개발한 알고리듬에서는 측정오차와 공간 및 상태에 대한 불완전 측정의 경우를 고려하였다. 개발한 알고리듬을 검증하기 위하여 3층 전단건물에 대한 수치 모의시험과 실내 모형실험을 통한 연구를 수행하였다.

Keywords

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