摘要: | 台灣地區存在許多使用老舊規範所設計之結構物,以及大量使用磚造或加強磚造結構,由於地震科學之不斷演進,使得這些老舊結構多不能滿足現階段耐震規範。由結構安全及耐久性的角度觀之,這些耐震能力不足之結構應予以進行適當之補強。含磚鋼筋混凝土結構在地震力作用之下為一複雜之非線性力學行為。在發展含磚鋼筋混凝土結構工法及規範的過程中,一般採用實驗及數值模擬二種方式進行之。本研究嘗試利用不連續變形分析法(DDA)和有限元素法(FEM)的結合,並加入鋼筋效應與水泥砂漿界面元素,來發展一個二維含磚鋼筋混凝土結構動態非線性行為的數值分析程序。 本研究中鋼筋行為是利用桁架元素模擬,並配合DDA塊體內的有限元節點配置來模擬鋼筋混凝土結構中鋼筋的效應。為模擬土木結構中磚牆的破裂現象,本研究亦嘗試建立磚塊間水泥砂漿介質破裂分析模型。其中磚塊嘗試用DDA塊體或DDA塊體再用有限元細分來模擬,而磚塊間的水泥砂漿則嘗使用界面元素來模擬,利用界面元素結點位移轉化為張力及剪力效應,同時亦希望能夠合理的找出水泥砂漿和介面元件所對應的關係,並加入水泥砂漿的破壞準則。開裂後塊體間之接觸互制行為,則使用DDA接觸判斷分析模式進行處理。 此一分析程序的功能與合理性,透過一系列數值算例並和實驗結果之比較進行驗證。 The behaviors of reinforced concrete structures containing brick wall under earthquake loading are quite complicated. It is very difficult to analyze the problem analytically. Experiment and numerical simulation are two possible solutions to extract reference information for the development of design code. However, the experimental approach requires much effort and expense to built very limited number of specimens to explore the behaviors of RC structures. The main advantage of using numerical simulation code to study the structural problem is that any detail response of the system can be detected easily from the calculated data. In this thesis, a computation code is developed based on the finite element method (FEM) and the discontinuous deformation analysis (DDA) theory. Each brick is modeled as a DDA block patched with finite element mesh. After cracking of mortar, the multi-body dynamics and contact analysis among bricks and RC frame are dealt by the DDA theory. Truss element is used to model the behavior of reinforcement inside the concrete and is tied up with the concrete at the node of concrete element. Both the nonlinear behaviors of the reinforcement and concrete material are considered into the analysis. To model the behavior of the mortar between bricks, a special interface element is developed. This element can provide suitable bond force between two blocks due to mortar. This interaction force can be reduced according to the interfacial friction and contact laws if interfacial cracking is identified. Besides, smear damage model of cracked concrete material is also acquired to adjust its coefficients of elasticity at Gaussian points according to the direction of crack surface. The accuracy and effectiveness of this simulation code were verified by some benchmark problems and experiment results of large-scale structural tests. |