本論文使用商業軟體ABAQUS執行有限元素法分析含HT690填充型混凝土箱型柱的軸向行為，並以實驗數據驗證分析模型之準確性，進而探討高性能鋼材(HT690)之局部挫屈發展情形及不同斷面形狀如方形及矩形混凝土圍束效應發展過程與機制。
研究結果顯示：（1）填充型箱型柱在發展出最大強度後，強度快速下降，此現象為內部混凝土碎裂後強度急遽下降導致，肢材寬厚比越大的試體，下降的幅度將越大。（2）當內部混凝土碎裂後，水平拱效應開始顯著，當柱板局部挫屈後，提供混凝土額外圍束作用，即垂直拱效應顯著，而當水平拱效應與垂直拱效應一起作用時，圍束作用顯著並使混凝土強度增加與回升，肢材寬厚比越大的試體，因局部挫屈變早而提早發展垂直拱效應（3）斷面長寬比越大的箱型柱，在拱效應的作用越不明顯，內部混凝土圍束行為越差，估計在弱軸承受彎矩時期撓曲延展性會更加顯著。

The main purposes of this research are to investigate the local buckling of CFBC with high Performance Steel (HT690) and the concrete confinement development process and mechanism of concrete-filled box columns with various cross-section aspect ratio. The axial behavior of the CFBC was simulated by using a commercial finite element program ABAQUS. The feasibility of the finite element models was verified by comparing the finite element analysis results to the experimental results. Based on FEM simulation results, the following conclusions can be drawn:
(1) The strength of CFBC specimens decrease rapidly after the first peak strength is reached. This phenomenon is mainly due to the strength drop of concrete when concrete crushed. The higher the b/t ratio of the column plate was, the faster the strength degradation resulted.
(2) Concrete confinement provided by horizontal arch action starts to become noticeable after concrete crushing. Vertical arch action, which provides additional concrete confinement, is developed after column wall buckling. Horizontal arch action combined with vertical arch action provides significant confinement to the concrete, and as a result, concrete started to gain its strength. A larger column plate b/t ratio resulted in an earlier development of vertical arch action.
(3) The larger the cross-section aspect ratio was, the less effective the horizontal and vertical arch actions were. It is predicted that this factor will reduce the flexural ductility of CFBC, especially when the column is subjected to weak axis moment.

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