本文藉由彈塑性大變形理論，分別針對具有碳纖維索及鋼索之斜張橋來建立靜態承載能力及靜態抗風能力之分析模式，以探討兩種索對中跨徑斜張橋靜態力學行為之影響。研究結果顯示，由於碳纖維索的勁度小於鋼纜索的勁度，因而中跨徑斜張橋改用碳纖維索後，主梁之彎矩及垂直變位、橋塔之彎矩及水平變位均有加大之現象；而纜索之拉力、主梁及橋塔之軸力則有減少之現象；此外斜張橋之靜態抗風能力將為之略減，但極限承載能力則為之大幅增加，故綜合而言，中跨徑斜張橋採用碳纖維索是一甚佳的選擇方案。 In this paper, the analytical models of middle-span cable-stayed bridges with carbon fiber composite cable and steel cable are established basing on the elastic-plastic large displacement theory. There are two models established in this paper, one is for analyzing the structural behaviors of the middle-span cable-stayed bridges under dead load and live load, the other is for those under wind load. In addition, the influence of cable to the structural behaviors of the middle-span cable-stayed bridges is examined as well.
The numerical results have shown that, the axial stiffness of carbon fiber composite cable is less than that of steel cable, due to the elastic modulus of carbon fiber composite cable less than that of steel cable. The results have also shown that after using carbon fiber composite cable, the moment and the vertical displacement of main girder, as well as the moment and the horrizontal displacement of tower have increased. However, the tensile force of cable and the axial force of main girder and tower have decreased. In addition, the static instability under wind load becomes significant while using carbon fiber composite cable, and the ultimate load-bearing capacity had increased. This research demonstrated that using carbon fiber composite cable instead of steel cable is an acceptable choice.
九十四年電子計算機於土木水利工程應用研討會論文集(I)=Proceedings of the conference on computer applications in civil & hydraulic engineering，頁126-131