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Flexural Vibration Characteristics of Prestressed Concrete Girders due to Changes in Prestress Forces

프리스트레스트 콘크리트 거더의 긴장력 변화에 따른 휨 진동 응답 특성

  • Received : 2009.02.04
  • Accepted : 2009.03.30
  • Published : 2009.07.30

Abstract

In this study, several flexural vibration characteristics of prestressed concrete girders due to changes in prestress forces are experimentally analyzed. In order to achieve the objective, the following approaches are implemented. First, several methods to extract vibration response features from output-only signal are selected. Next, a large-scaled prestressed concrete girder model is constructed to analyze relation between the prestress forces and the vibration features in the prestressed concrete girder. Then acceleration responses are measured from the girder for several prestress force scenarios. Finally, vibration characteristics of the prestressed concrete girder due to change in prestress force are experimentally analyzed. The values of features extracted by the selected methods are reduced due to prestress-loss. Especially, the value of features are linearly reduced in the early prestress-loss.

본 논문에서는 프리스트레스트 콘크리트 거더의 긴장력 변화에 따른 몇 가지 휨 진동 응답 특성을 실험적으로 분석하였다. 이를 위해, 먼저 구조물의 진동응답특성을 추출하기 위한 기법들을 선정하였다. 진동응답특성은 기존에 많이 이용되는 고유진동수도 포함하였다. 다음으로, 프리스트레스트 콘크리트 거더의 긴장력과 휨 진동 응답 사이의 관계를 살펴보기 위해 모형 프리스트레스트 콘크리트 거더를 제작하고, 긴장력 변화 시나리오에 따라 진동응답실험을 수행하였다. 마지막으로, 긴장력 변화 시나리오에 따라 취득된 동적응답신호를 이용하여 선정된 진동응답특성 분석기법을 적용하였으며, 긴장력과 휨 진동 응답특성 관계를 분석하였다. 선정된 기법들에 의한 진동응답특성은 전체적으로 긴장력 감소에 따라 감소하는 경향이 있으며, 긴장력 감소가 나타나는 초기에는 비교적 선형적으로 감소하였다.

Keywords

Acknowledgement

Supported by : 한국과학재단

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