CFRP-钢管RPC短柱轴压承载力分析

Analysis of Axial Compression Bearing Capacity of CFRP Confined RPC Filled Steel Tube Columns

基于统一强度理论,充分考虑中间主应力对碳纤维增强复合材料(CFRP)-钢管活性粉末混凝土(RPC)短柱的影响,考虑钢管与RPC处于三向应力状态,CFRP处于环向受拉应力状态,推导得出了CFRP-钢管RPC受压短柱的极限承载力公式.在此基础上进一步提出了考虑界面黏结影响和尺寸效应的CFRP-钢管RPC轴压短柱的承载力统一解.将理论计算结果与有关文献的试验数据进行对比,验证了理论计算公式的正确性.研究结果表明:考虑了界面黏结影响和尺寸效应的计算结果与试验结果吻合更好,且试件尺寸越大,尺寸效应越明显,计算结果越贴合试验结果,并进行了参数分析,同时得到中间主应力系数、钢管套箍指标和摩擦系数等对承载力的影响规律.

Based on the unified strength theory, the calculation formula of bearing capacity of CFRP confined RPC filled steel tube columns under the axial compression was deduced considering the intermediate principal stress and the assumptions that steel tube and RPC are both in a three-dimensional stress state and CFRP is in a uniaxial tensile stress state. Based on this, new ultimate bearing capacity formula was derived considering the bond strength and the size effect. Comparing the theoretical results with the experimental data, the model considering the interface bond and the size effect match better with the relevant experimental data. The good comparison agreement verifies the correctness of the theoretical formula. The larger the specimen size is, the more obvious the size effect is, and the better the calculation results match the test results. The effects of the intermediate principal stress, the confinement index and the friction coefficient on the bearing capacity were obtained through the parametric analyses.