DLV法在結構破壞偵測之應用

Abstract

本研究應用Bernal所提出之DLV損傷識別法，配合ARX系統識別方法，發展一套以結構地震反應量測訊號為依據之結構破壞偵測技術。DLV損傷識別法是以振動量測結果推估之系統柔度矩陣為基礎的結構破壞偵測技術，其概念乃在於識別出那些在特定荷載形式下，應力為零之破壞桿件。數值模擬分析結果顯示， 無論是二維或三維之剪力架構、桁架結構與抗彎構架等各種型式之結構，DLV損傷識別法均能適用。針對模擬分析結構設定之不同破壞位置、多重損害桿件及不同破壞程度，應用DLV損傷識別法皆可準確判別出來，尤其在結構構件僅輕微受損﹙2%﹚時都能有效偵測出破壞位置，顯示這個方法具有相當之敏感性及強韌性。試驗分析結果顯示，考慮之模態數愈多時，愈能充份反映結構行為，增加破壞偵測的準確性。計算柔度矩陣時所考慮之模態數必須大於或等於所破壞的桿件數量，方能確保可準確辨識出受損之桿件。本文經由完整之參數研究與試驗驗證，確認DLV損傷識別法應用於結構破壞偵測之可行性，以及使用上之可能限制。

The structural damage detection method integrating the DLV method proposed by Bernal and the ARX system identification model has been proposed in this study by using the accelerometer-recorded structural responses induced by earthquakes. The DVL damage detection method is performed based on the structure’s flexibility matrix that can be estimated through the vibration measurement data. The concept of the DLV method is to identify the damaged members with zero stress under some specific loading. The simulation results show that the DLV method is applicable to two or three dimensional shear-type frames, truss structures and moment-resisting frames. The damaged locations, multiple damaged members, and different damage level of damaged members assigned in the simulation model can be accurately identified by using the DLV method, even the member is slightly damaged (2%), indicating that DLV is a sensitive and robust method for structural damage detection. Moreover, the experimental results show that the more the number of the mode shape considered, the better the accuracy of the damage detection. Furthermore, to accurately identify the damaged members, the number of the mode shape considered to calculate the flexibility matrix must be greater than or equal to the number of the damaged member. In This study, the limitation and the feasibility of using DLV to identify the damaged members of the structure has been demonstrated and verified through parametric study and a series of shaking table tests.