圆钢加固钢管混凝土偏压构件弯曲性能提升机制  

Improvement mechanism for flexural performance of eccentric concrete-filled steel tube members reinforced with round steel

作　　者：刘德军[1,2] 夏志恒 王军[3] 左建平[1,2] 常永全 LIU Dejun;XIA Zhiheng;WANG Jun;ZUO Jianping;CHANG Yongquan(State Key Laboratory of Coal Resources and Safe Mining,Beijing 100083,China;School of Mechanics and Civil Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;School of Civil Engineering,Shandong Jianzhu University,Jinan 250101,China)

机构地区：[1]煤炭资源与安全开采国家重点实验室,北京100083 [2]中国矿业大学(北京)力学与建筑工程学院,北京100083 [3]山东建筑大学土木工程学院,济南250101

出　　处：《哈尔滨工业大学学报》2023年第5期122-131,共10页Journal of Harbin Institute of Technology

基　　金：国家自然科学基金(51878658);煤炭资源与安全开采国家重点实验室-北京高等学校卓越青年科学家计划项目联合基金资助(SKLCRSM20LH03);中央高校基本科研业务费资助(2022JCCXLJ05)。

摘　　要：为探索拱腹焊接圆钢对钢管混凝土偏压构件弯曲性能的提升机制,在ABAQUS软件中建立了圆钢加固钢管混凝土梁数值模型,并采用试验数据验证了模型的合理性。通过分析圆钢加固钢管混凝土偏压构件的弯矩-挠度曲线、弯矩-纵向应变曲线、环向应变曲线、约束指数和中性轴偏移规律,揭示了焊接圆钢对钢管混凝土偏压构件弯曲性能的提升机制。进一步,分析了圆钢直径以及构件长细比对圆钢加固钢管混凝土偏压构件弯曲性能的影响规律。结果表明:焊接圆钢可以降低截面中性轴的位置,增大受压侧钢管环向应变,从而提高了受压区混凝土面积,增强了受压侧钢管对混凝土的约束作用,进一步提升钢管混凝土偏压构件的抗弯承载力和弯曲刚度,并且圆钢直径越大提升幅度越高;圆钢加固钢管混凝土偏压构件的极限弯矩随着轴压比的增加而减小,减小的幅度随着圆钢直径和构件长细比的增加而增大,焊接圆钢提升大长细比偏压构件弯曲性能的效果更好,且对大长细比构件弯曲性能的提升效果随着轴压比的增加而增大。To explore the improvement mechanism of welding round steel at soffit on the flexural performance of eccentric concrete-filled steel tube(CFST)members,we established a numerical model of CFST beams reinforced with round steel by using ABAQUS software and verified the model by test results.By analyzing the bending moment-deflection curve,bending moment-axial strain curve,hoop strain curve,restraint index,and neutral axis offset of eccentric CFST members reinforced with round steel,the improvement mechanism of the flexural performance of the eccentric CFST members was revealed.Besides,the influence of the diameter of the round steel and the slenderness ratio of the beams on the flexural performance of eccentric CFST members reinforced with round steel was analyzed.Results show that welding round steel could lower the position of the neutral axis of the section and increase the hoop strain of the steel tube on the compression side.Therefore,the concrete area in compression was increased,and the restraint effect of the steel tube on the compression side on the concrete was enhanced.Furthermore,the flexural bearing capacity and flexural stiffness of the eccentric CFST members were improved,and the larger the diameter of the round steel,the greater the improvement.The ultimate bending moment of the eccentric CFST members decreased with the increase in the axial compression ratio,and the larger the diameter of round steel and the slenderness ratio of beams,the greater the reduction.Welding round steel had a better effect on improving the bending performance of the eccentric member with a large slenderness ratio,and the larger the axial compression ratio,the better the improvement effect.

关 键 词：钢管混凝土 数值模拟 焊接圆钢 偏压构件 弯曲性能 轴压比 长细比 

分 类 号：TU398.9[建筑科学—结构工程]