方GFRP-橡胶混凝土-钢双管组合长柱轴压性能研究

Study on Axial Compressive Performance of GFRP-Rubber Concrete-Steel Double-Skin Tubular Long Columns

为研究GFRP-橡胶混凝土-钢双管组合柱(GFRP-rubber concrete-steel double-skin tubular columns,RCDSTCs)的轴压性能,对7个长柱试件进行了轴压试验。观察RC-DSTCs在轴压状态下的破坏模式,基于荷载-位移曲线、荷载-应变曲线和环向-轴向应变曲线分析了长细比、空心率对RC-DSTCs轴压性能的影响,提出了RC-DSTCs的轴压理论承载力计算式。结果表明:随着长细比的提高,RC-DSTCs的轴压破坏模式由材料破坏向弯曲失稳破坏转化,但所有RC-DSTCs的钢管均达到了屈服应变0.2%;同时,随着长细比的提高,RC-DSTCs的峰值荷载、GFRP管约束作用及延性显著降低;而随着空心率从0.3增加至0.4,RC-DSTCs的延性有明显提高;RC-DSTCs的轴压承载力计算结果与试验结果比较吻合,可为后续工程应用提供参考。

To investigate the axial compressive performance of GFRP-rubber concrete-steel double-skin tubular columns(RCDSTCs),axial compressive tests were conducted on 7 long column specimens.The failure modes of RC-DSTCs under axial compression were observed.The effect of slenderness ratio and void area ratio on axial compressive performance of RC-DSTCs were analyzed by load-displacement curve,load-strain curve and hoop-axial strain curve.Moreover,a theoretical axial compressive capacity calculation formula for RC-DSTCs was proposed.Results indicate that with an increase in slenderness ratio,the axial compressive failure modes of RC-DSTCs transition from material failure to flexural instability failure.But the yield strain of steel tubes in RC-DSTCs reached 0.2%.Moreover,with an increase in slenderness ratio of RC-DSTCs,their peak load,GFRP tube confinement effect,and ductility significantly decrease.When the void area ratio of RC-DSTCs increases from 0.3 to 0.4,their ductility significantly increase.Ultimately,the theoretical axial compressive capacities of RC-DSTCs agree well with experimental results.It can provide a valuable reference for future engineering applications.