摘   要：通过6个FRP-混凝土-钢管组合方柱的试验研究，考察在轴心受压情况下，组合柱内混凝土的受力性能。结果表明：组合柱在加载后期表现出了良好的延性，且由于内、外管的双层约束，组合柱中混凝土强度均得到了一定程度的提高。通过分析本文和国内外相关试验结果，提出了FRP-混凝土-钢管组合方柱中混凝土的峰值应力和峰值应变的计算公式，经验证计算值与试验值吻合较好。

Abstract: Through the experiment study of 6 FRP-concrete-steel tube composite square columns under axial concentric compression, the mechanical behavior of the concrete of composite columns is investigated. The results indicate that the composite columns show good ductility in the last stage of loading, and due to the double-skin confinement from the inner and outer tubes, the strength of concrete of composite columns is improved to some degree. Through analyzing the related experimental results from this paper as well as China and abroad, new formulas for the peak stress and peak strain of the concrete of FRP-concrete-steel tube composite square columns are put forward, and the calculated values agree well with the test ones.