本研究採用非線性纖維元素法(Nonlinear fiber element method)建立考慮局部挫屈與二次彎矩效應之鋼管混凝土柱(Concrete-filled steel tube, CFT)的P-M互制曲線。多組方形CFT柱之最大軸壓強度與軸壓-單軸彎矩強度試驗數據用來驗證，纖維元素法分析結果的合理性。結果發現纖維元素法在分析CFT柱所計算的最大軸壓強度與彎矩強度，和試驗結果差異約略在合理範圍以內。另外，本研究亦藉由方形與矩形CFT柱軸壓-彎矩互制曲線進行參數研究，探討鋼管寬厚比、混凝土強度、鋼材降伏強度、偏心角、有效長度、初始幾何缺陷和偏心距等參數，對CFT柱軸壓-彎矩強度互制曲線的影響。;This study presents nonlinear fiber element method determine the axial load-biaxial bending moment interaction curves of concrete filled steel tubular beam-columns (CFT) with local buckling and second-order effect. Many experimental ultimate loads and axial load-uniaxial bending moment stengths of square CFST slender beam-columns tested by independent researchers are used to verify the rationality of the fiber element method analysis. The predicted results of fiber element analysis method show good agreement with the uniaxial bending and ultimate load tests. In the study, an extensive parametric study was performed to investigate the influences of width-to-thickness ratio, concrete compressive strengths, steel yield strengths, load angle, columns slenderness, initial geometric imperfect, loading eccentricity on the axial load-biaxial bending moment interaction curve of concrete-filled steel tubular beam-column.
