环形脱空对圆钢管混凝土柱抗侧向冲击性能的影响分析  

Investigations on the influence of circumferential gaps on the lateral impact behaviour of circular CFST columns

作　　者：沈奇罕 刘俊杰 朱维军 王静峰[1,3] 谢强 SHEN Qihan;LIU Junjie;ZHU Weijun;WANG Jingfeng;XIE Qiang(College of Civil Engineering,Hefei University of Technology,Hefei 230009,China;Engineering Research Center of Low-carbon Technology and Equipment for Cement-based Materials,Ministry of Education,Hefei University of Technology,Hefei 230009,China;Anhui Collaborative InnovationCenter for Advanced Steel Structure Technology and Industrialization,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学土木与水利工程学院,合肥230009 [2]合肥工业大学水泥基材料低碳技术与装备教育部工程研究中心,合肥230009 [3]合肥工业大学先进钢结构技术与产业化安徽省协同创新中心,合肥230009

出　　处：《振动与冲击》2024年第16期92-102,145,共12页Journal of Vibration and Shock

基　　金：国家自然科学基金(52108129);博士后面上项目(2022M713388);中央高校基本科研业务费专项(JZ2023HGTB0260)。

摘　　要：近年来随着社会机械化水平的不断提高和交通事业的飞速发展,车辆、船舶及飞行器等机械撞击城市高架、跨河桥梁墩柱等事故的发生频率显著提升。而实际钢管混凝土(concrete-filled steel tubular, CFST)结构由于材料特性或服役环境等问题普遍存在脱空缺陷情况,但目前有关脱空缺陷对CFST冲击性能的影响研究仍相对较少。为此,构建了侧向冲击作用下含环形脱空圆钢管混凝土柱有限元分析模型,并通过相关试验验证模型的准确性。揭示了环形脱空对圆钢管混凝土柱在侧向冲击作用下破坏模式、时程曲线特征、冲击全过程应力应变发展和界面接触行为的影响机理,系统研究了脱空率、轴压比、边界条件、径厚比、冲击速度和冲击质量等诸多参数对侧向冲击作用下含环形脱空圆钢管混凝土柱冲击力、挠度变形和耗能等动力响应的影响规律。结果表明,环形脱空的存在将逐步降低圆钢管混凝土柱的抗侧向冲击能力。随着脱空率的增大,圆钢管混凝土柱的冲击力和耗能逐步减小,挠度变形相应增大。同时,由于缺乏混凝土的有效支撑,钢管在侧向冲击作用下的凹陷变形程度也随着脱空率的增大而愈发显著。The frequency of vehicle and ship impact accidents acting on the piers of city viaducts and river-crossing bridges is highly improved in recent years.Nevertheless,the concrete gap defect is observed to commonly exist in concrete-filled steel tubular(CFST)engineering practices,due to disadvantageous factors in material properties and working environment.While few investigations on the lateral impact behavior of CFST members with concrete gap defects have been reported.Therefore,this paper developed a finite element(FE)model of circular CFST column under lateral impact considering the feature of the circumferential gap,and the accuracy of the FE model is validated by some relative experiments.The influence mechanism of circumferential gaps on the typical failure modes,the featured time history curves,the stress/strain distribution rule during the full-range impact process and the steel-concrete contact bahaviour of the circular CFST column is revealed in detail.Moreover,the effect of gap ratio,axial compression ratio,boundary condition,diameter/thickness ratio,impact velocity and impact mass,etc.on the impact force,the flexural deflection and the energy dissipation is investigated systematically.The results shows that the lateral impact resistance of the circular CFST column is gradually weakened by the existence of circumferential gap.With the increase of circumferential gap ratio,the impact force and energy dissipation of the circular CFST column are reduced by degrees,while the flexural deflection shows an opposite trend.In addition,the local depression degree of the steel tube under lateral impact would be more obvious with the increase of void ratio,due to the lack of efficient supporting effect provided by the core concrete.

关 键 词：环形脱空 钢管混凝土(CFST) 侧向冲击 数值分析 破坏机理 

分 类 号：TU398.9[建筑科学—结构工程]