預力混凝土構件大量用於現代化之先進式施工法，以提昇結構之淨跨距並承受高負載之反覆荷重；但常因超出設計荷重之活載重或地震力作用，致預力混凝土梁構件產生開裂破壞行為，並降低極限承載能力。故採用FRP 疊層材料（Fiber Reinforced Plastics）補強修復預力混凝土構件，實為現今較經濟且節省工時之主流；提具合理且信賴度高之數值分析模式，藉以準確預測補強後預力構件的極限強度及開裂相關趨勢，供工程實務界欲採用該工法進行補強時之參照。
本文使用有限元素ABAQUS 分析軟體，針對FRP 疊層材料補強預力混凝土T形梁提出非線性有限元素分析理論。分析之數值模型依構件結構尺寸分為長梁和短梁兩種，預力混凝土梁中初始預力施加方式分為低預力量、中預力量及高預力量三種情形，外力載重之施加為靜態單調持續加載方式，整體預力混凝土梁分析則採取靜力分析模式；另於FRP 補強型式上可分為梁底面補強及梁腹版兩側補強，並就FRP疊層材料補強之不同疊層數與黏貼纖維角度進行參數分析，藉此探究其補強後之預力混凝土梁之極限載重及開裂行為之變化趨勢。

Prestressed concrete structures are frequently used in modern advanced construction methods to increases the span of structures and enhance the bearing capacity under cycling loading. However, prestressed concrete members are usually damaged or cracked and reduce their ultimate loading capacity due to the live load exceeding the design load or the effect of the earthquake force. Therefore, the use of Fiber Reinforced Plastic (FRP) to enhance and repair prestressed concrete members is the mainstream construction method that is more economical and time-saving than traditional processes. Furthermore, employing the reasonable and reliable numerical analysis model in advance is required to precisely predict reinforced prestressed concrete members’ ultimate strength and tendency to crack, which can serve as reference for practitioners to reinforce their construction.
This paper presents a nonlinear model of prestressed concrete T-shaped beams strengthened by FRP with the Finite Element Analysis (FEA) software package, ABAQUS. The analyzed models are divided according to their size, into long beams and short beams. In addition, there are low, middle and high prestressed forces in regard to the exertion of the initial prestressed forces. As for the types of FRP reinforcement, there are reinforcements in the bottom face as well as the lateral face of the beams. The parameter analysis is carried out in layers and angles of the FRP reinforcements. Under the above conditions, this paper aims to explore the ultimate loading of prestressed concrete structures strengthened by FRP and the variations of beam cracks.

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