A Study On Damage Indices of the MDOF Reinforced Concrete Structures

本文內容主要在探討歷年來眾多研究學者所定義的結構物在地震作用下之損傷指標，什麼是損傷指標呢?是指結構物在受到地震的作用下所產生出的一連串的反應參數，接著再由所建立出來的一套計算流程將損傷程度給予量化。因此我們就可以藉著損傷指標，初步去了解結構物的損傷程度，用來判斷結構物是否需要修補或拆除。 當結構物遭受到一個大的地震力的作用下，使結構物的自然頻率開始發生改變，而藉由頻率的改變來判斷結構物的損傷程度。在這裡使用最小平方法，用來當作結構系統識別的方法，來求得此結構系統的阻尼比和頻率，接著在用Newmark-β Method來驗證其準確性，而後再以最大軟化指標和勁度衰減指標來判斷其結構物的損傷程度。最後在以一個需要考慮材料參數以及由結構物之位移和反覆載重作用下之能量消散組合而成的指標，即Park and Ang 破壞指標來計算出其柱子的損傷程度。緊接著再將所使用到的三種指標，最大軟化指標、勁度衰減指標、Park and Ang 破壞指標作一個整理並且比較其優缺點。 最後，透過由國家地震中心所作之1/2.25縮尺之兩層兩跨鋼筋混凝土構架振動台試驗所取得的歷時反應以及構架的材料參數作為實例識別的量測值，進行實例的分析。而後經由識別出的結果以及各損傷指標所計算出來的結果作一個比較和結論。This paper mainly discussed over the years , many researchers in the definition of structure of the damage index under the earthquake , What is the damage index ? Means the structures in the role by the earthquake generated a series of reaction parameters , and followed by the calculation created out of a given process will quantify the degree of injury . Therefore , we can use damage index to understand the structure of the initial damage , and to determine the structure should be repaired or removed . When under the strong earthquake , structure began to change the natural frequency , and to judge the damage of structure by the frequency change . In the thesis , we use Least-square method as a method of structural system identification , to obtain the structure of the system damping ratio and frequency , then use the Newmark-β Method to verify the accuracy , and determine the damage of structure by Maximum softening and Damage Index of Stiffness . Finally , consider the material parameters and the displacement of the structures under cyclic loading and the energy dissipation of a combination of index . It is Park and Ang damage index to calculate the damage of column . Then use three indices mentioned above to make an order, and compare their advantages and disadvantages . Finally , we use the 1/2.25 scale of two –floor and two-span reinforced concrete structures of shaking table test by NCREE , to get the reaction and the structure of the material parameters as the examples to analyze . Then , through the results by system identification and damage indices to make a comparison and conclusion