應用子空間系統識別法於結構安全性評估

Seismic Safety Assessment of Structures using Recursive Subspace Identification

余以諾(I-No Yu)

指導教授 ： 羅俊雄

國立臺灣大學/工學院/土木工程學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201801382

摘要

本研究主要目的為，基於遞迴子空間識別法(Recursive Subspace Identification, RSI)與二階段結構損傷識別理論，提出一套自動化結構健康監測的方法，本方法可以分為四大部分，第一，利用頻率響應函數(Frequency Response Function, FRF)進行希爾伯特轉換(Hilbert Transform, HT)，透過其差異性來判斷系統是否進入到非線性行為。第二，若結構物進入到非線性行為，則開始進行損傷評估，利用自動化主波監測(Automatic Dominant-Wave Arrival Detection)來決定遞迴子空間識別法的起始資料點。第三，將遞迴子空間識別法所識別的模態參數(Modal Parameter)進行二階段結構損傷理論，計算結構物勁度折減。第四，評估結構損傷狀態，根據美國聯邦緊急事務管理署提出的規範Hazus-HM2.1，由層間變位判別損傷狀態，此階段目前應用於實驗結構物。在進行自動化分析時，遞迴子空間系統識別法在部分窗函數訊號不穩，導致識別結果的不連續性，會造成二階段結構損傷識別理論的分析困難。本文提出三個唯輸出(Output-Only)訊號分析方法，可以應用於重建模態參數的連續性。本研究透過提出的自動化結構健康監測方法，應用於實驗以及實際結構，成功的識別損傷位置與時間，並量化損傷狀態。

關鍵字

自動化結構健康監測 ； 遞迴子空間識別法 ； 線上系統識別 ； 結構損傷識別 ； 損傷指標

並列摘要

The purpose of this research is to proposed an automatic health monitoring method, based on Recursive Subspace Identification (RSI) method and two-stage damage detection algorithm. This method can be divided into three parts: First, use of the difference between frequency response function and Hilbert transform of frequency response function to determine if the structure become non-linear behavior or not. Second, if structures have become non-linear behavior, use the Automatic Dominant-Wave Arrival Detection to decide the starting data point of recursive subspace identification analysis. Third, Use the modal parameter identified by RSI method to conduct two-stage damage detection algorithm and calculate the stiffness reduction. Fourth, according the Hazus-MH2.1 published by Federal Emergency Management Agency, the damage-state of generic buildings were defined in the value of average inter-story drift ratio. While using the automatic structural health monitoring method, the unstable of RSI identified results will cause the difficulty of two-stage damage detection algorithm. This research proposed three output-only signal analysis methods to apply on the reconstruct the continuity of the identified results of RSI. The research applies automatic structural health monitoring method on both experimental structure and practical structure to successfully localize and quantify the damage, and the damage occurrence during the earthquake excitation.

並列關鍵字

Automatic structural health monitoring method ； Recursive Subspace Identification ； Online System Identification ； Structure damage detection ； Damage Index

參考文獻

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