코사인 유사도를 이용한 진동기반 구조건전성 모니터링 전략

Abstract

Offshore structures have high risks of damage because they are exposed to harsh environmental conditions such as a current, pressure, high tension and vortex in-duced vibration. Therefore, it is significant to retain their performance and to de-tect damage before the structure failure is occurred. For these reasons, an accurate health monitoring method for offshore structures should be developed to detect and localize potential damages. This paper presents an effective vibration-based structural health monitoring using a cosine similarity and sensor data. This vibra-tion-based strategy uses the rate of changes of natural frequencies before and af-ter occurrence of various damage scenarios including not only single but also multiple damages. The proposed method alerts occurrence of damage with nor-malized warning index which facilitates workers to manage risks of damage. By the method, moreover, the case most similar with the current status is directly fig-ured out without any additional analysis between monitoring and damage identifi-cation, which renders damage identification process simpler. Numerical examples are considered to verify the performance of the proposed method. As aresult, the damages in the structures are accurately detected.