纤维增强复材-混凝土-钢管组合实心方形短柱轴压承载力分析

ANALYSIS OF AXIAL BEARING CAPACITY OF FRP-CONCRETE-STEEL COMPOSITE SOLID SQUARE COLUMN

以纤维增强复材(FRP)-混凝土-钢管组合实心方形短柱为研究对象,根据夹层混凝土受到约束作用的不同,将其划分为有效约束区和非有效约束区;同时考虑夹层混凝土受到的双重约束,将方形纤维增强复材布转化为圆形FRP布。基于统一强度理论,考虑中间主应力、材料拉压比以及倒角半径的影响,推导得到FRP-混凝土-钢管组合实心方形短柱的轴压承载力计算式。将理论计算结果与相关文献试验结果对比,吻合良好,证明了算式的正确性和合理性。对影响因素的分析表明:轴压承载力随中间主应力系数、侧压系数的增加而变大,随着倒角半径的增大先增大后减小,随着钢管径厚比的增大而减小。

Taking FRP-concrete-steel composite solid square stub column as object of study,the sandwich concrete was divided into effective constraint region and invalid constraint region according to the different constraint degree of sandwich concrete. Considering the double effect of restraint of core concrete,the square FRP pipe was equivalent to circular FRP pipe. Based on the unified strength theory,the influences of intermediate principal stress parameter,the tension and compression ratio of material,chamfering radius were considered,the calculation formula of axial bearing capacity of FRP-concrete-steel composite solid square stub column was deduced. Comparing the calculation results with relevant experiment results,the good comparison result can illustrate the correctness and rationality of the theoretical formula. Analytic results of various influential factors showed that axial bearing capacity of FRP-concretesteel composite solid square stub column increased with the increase of intermediate principal stress parameter and side pressure coefficient,and increased firstly and then declined with the increase of chamfering radius,while decreasing with increase of radius-thickness ratio.