GFRP管-钢管双壁约束混凝土组合柱轴压性能与承载力实用计算方法研究

通过4根实心和中空的GFRP管-钢管双壁约束混凝土组合短柱轴压试验,对比分析了该组合柱的工作机理、破坏模式、复合材料管的约束效应、核心混凝土本构关系及其影响因素。研究发现,在其他条件相同的情况下,内钢管空心的构件变形能力超过实心构件,极限承载力小于实心构件,GFRP管对混凝土的约束程度低于实心构件;GFRP管径厚比越小,其对混凝土的约束效应越好。GFRP管径厚比相同的情况下,实心构件混凝土峰值应力比空心构件大,而极限应变比空心构件小。通过试验分析了约束混凝土强度模型,并采用极限平衡法推导了可用于计算实心和空心双壁约束混凝土组合柱轴压承载力的计算公式,理论计算与试验结果吻合较好。

Experiment and capacity calculation theory research of hybrid GFRP-concrete-steel double skin tubular columns under axial compression

Through axial compression experiment of four solid and hollow hybrid GFRP-concrete-steel double skin tubular short columns,the working principle,failure mode,GFRP tube constraint effect and core concrete constitutive relation,as well as their influence factors under whole axial loading,were contrasted and analyzed.The results indicate that,if other conditions are same,deforming ability of hollow hybrid columns exceeds that of solid hybrid columns,while axial bearing capacity and GFRP constraining effect to concrete are lower than those of solid hybrid columns.Smaller the ratio of GFRP tube’s diameter and wall thickness owe,better the restraint effect of GFRP tube is.In the same condition of GFRP tube diameter and wall thickness ratio,the maximum concrete stress of solid columns is larger than that of hollow columns,while the maximum strain is smaller than that of hollow columns.Confined concrete strength was analyzed through tests,then the axial bearing capacity calculation formulas of solid and hollow hybrid columns were derived by ultimate equilibrium method.Experiment results confirmed the good agreement with the formula results.