鋼管混凝土結構承受地震力作用時，常因局部挫屈發生而減低構 件之承載力，因此如何避免局部挫屈為此類構件設計的重要考量。而 矩形鋼管混凝土柱的局部挫屈模式為兩相對鋼板發生向外之相對位 移，若能在局部挫屈區域進行有效控制，使鋼板上具有抑制向外的束 制力，以延緩局部挫屈的發生，並減緩構件強度衰減速率，將可有效 提昇構件效能。 本研究應用繫桿束制鋼板塑性鉸相對位移之發生，並以ABAQUS 有限元素分析軟體模擬加勁鋼管構件受力情形，作為規劃實驗繫桿配 置之參考。由方形鋼管混凝土柱同時承受固定軸力與反覆側向載重作 用下之強度、勁度、韌性與消能行為，探討此束制方式對局部挫屈與 構件破壞模式的影響。 研究結果顯示，繫桿加勁可提供鋼管有效束制力，延後初始挫屈 之發生，對構材極限強度與勁度衰減影響不大，但對後挫屈強度則有 明顯提升。繫桿加勁對韌性與能量消散方面亦皆有所助益，其中在高 軸力作用下，雙層加勁在寬厚比較小之構件，對韌性與消能能力提升 最佳，對寬厚比較大之構件，則以單層加勁提升效果較顯著。 Major concern in concrete-filled tube (CFT) design is to avoid premature local buckling so that member performance can be sustained. Post-buckling performance of CFT members under lateral load is governed by the deterioration rate of tube plates at plastic hinge region. Therefore, study of method to reduce plate deformation and to increase energy dissipation capacity during post-buckling stages is essential to the seismic performance of such design. This study is focused on the performance improvement of CFT members by applying pairs of tie rods to restrain relative plate deformations after members are locally buckled. Placements of tie rods were determined by the results from analytical simulations. Test results show that the tie rods effectively restrained the development of plate deformation and delayed the occurrence of local buckling. It is found from comparisons that member strength and stiffness were not influenced by the application of tie rods. It is also confirmed from test results that energy dissipation capacities of members with tie rods were significantly enhanced.
