外贴CFRP布加固不锈钢和普通钢方管短柱轴压性能研究

通过对环向外贴碳纤维布（CFRP）加固不锈钢和普通钢方管短柱的轴压试验和数值模拟研究基轴压性能。结果表明，不锈钢和普通钢方管未加固短柱和加固试件的轴压破坏模式均为对称局部屈曲；CFRP布加固试件的轴压承载力与未加固试件相比均有明显提升，对于相同宽厚比的试件，4层环向加固的效果优于2层环向加固的；随着截面宽厚比的增加，试件的承载力提高百分比随之增加。同时，采用精细化有限元分析模型研究了不同宽厚比试件环向外贴CFRP布加固后的承载力；最后，基于受压薄壁截面的有效截面概念，提出了环向CFRP约束方管有效截面的假设，推导了环向CFRP布加固不锈钢和普通钢方管短柱轴压承载力的计算方法，并与本文试验结果、文献数据和有限元拓展参数模拟结果对比,验证了所提计算方法的有效性和适用性。

Axial capacity of stainless steel and conventional carbon steel square short columns retrofitted with CFRP sheets

The performance and bearing capacity of short columns of stainless steel and conventional carbon steel square tube strengthened by transverse carbon fiber reinforced polymer (CFRP) were studied through axial compression test and numerical simulation. The results show that the failure modes of control specimens and reinforced specimens of stainless steel and conventional carbon steel square tube short columns under axial compression are symmetrical local buckling. The ultimate bearing capacity of CFRP reinforced specimens is significantly improved compared with the control specimens. For specimens with the same width-thickness ratio, the reinforcement effect of four layers is better than that of two layers. With the increase of width-thickness ratio, the percentage of bearing capacity of members increases accordingly. At the same time, the bearing capacity of specimens with different width-thickness ratios strengthened by CFRP was studied by refined finite element simulation. Finally, based on the concept of effective section of compressed thin-walled section and the assumption of transverse CFRP only confining the effective section of square tube, the calculation method of ultimate bearing capacity of stainless steel and conventional carbon steel square short columns strengthened with CFRP sheets was deduced and compared with the experimental results, literature data and finite element simulation results to verify the validity and applicability.