CFRP约束钢管高强混凝土轴压短柱承载力的极限分析

Limit Analysis of Bearing Capacity of CFRP Confined High Strength Concrete Filled Steel Tube Stub Columns Under Axial Compression

为研究碳纤维增强树脂复合材料(carbon fiber reinforced polymer,CFRP)约束钢管高强混凝土短柱在轴心受压作用下的极限承载力,对CFRP约束钢管高强混凝土轴压短柱破坏过程工作机制进行探讨,分析CFRP约束钢管高强混凝土与CFRP约束钢管混凝土构件的主要区别与联系,为CFRP约束钢管高强混凝土短柱承载力的极限分析奠定基础。基于极限平衡法,对高强混凝土、钢管和CFRP进行应力分析,推导得到CFRP约束钢管高强混凝土短柱的理论计算公式,将理论计算结果与试验实测值相比较,验证理论公式的正确性。最后将理论计算结果随CFRP层数和钢管壁厚的变化规律进行分析,研究表明:与CFRP约束钢管混凝土相比,CFRP约束钢管高强混凝土中CFRP约束效果较差,而对于CFRP约束钢管高强混凝土轴压短柱承载力的提高,厚壁钢管有较大优势。

To study the ultimate bearing capacity of carbon fiber reinforced polymer(CFRP) confined high-strength concrete filled steel tube stub columns under axial compression,the failure process and working mechanism of CFRP confined high-strength concrete filled steel tube(CFRP confined steel tube-HSC) stub columns under axial compression was discussed. The main differences and relationship between CFRP confined steel tube-HSC and CFRP confined concrete filled steel tube(CFRP confined steel tube-C) stub columns members were analyzed, which laid the foundation for the ultimate analysis of the bearing capacity of CFRP confined steel tube-HSC stub columns. Based on the limit equilibrium method, the stress analyses of HSC, steel tube and CFRP were carried out. The theoretical calculation formula of CFRP confined steel tube-HSC stub column was derived. The theoretical formula was verified by comparing the calculated results with the measured ones. Finally, the variations of the theoretical calculation results with the number of CFRP layers and the thickness of steel tube wall were analyzed. The results showed that compared with CFRP confined steel tube-C, CFRP confined steel tube-HSC had a poor constraint effect. For the bearing capacity improvement of CFRP confined steel tube-HSC stub column, the thick wall steel tube had a great advantage.