摘要
开展了4个翼缘削弱的钢管混凝土柱穿入式组合节点抗震性能与三维实体有限元精细化模型分析。在混凝土三轴塑性损伤和钢材混合强化模型基础上,进一步引入钢材的韧性损伤模型,探讨了钢梁削弱程度对节点抗震性能与破坏形式的影响规律,结果显示引入钢材韧性损伤的有限元模型分析结果与试验结果更加吻合,且钢梁削弱程度降低了该节点的刚度、承载力和耗能。随后对不同钢梁尺寸和柱端拉筋强构造下的组合节点进行了承载力、刚度和塑性耗能分配与失效机制的影响规律分析,分析结果表明:穿入式节点分别在梁-柱抗弯承载力比介于1.66~2.11、梁-柱线刚度比介于1.90~1.96、梁-柱截面刚度比介于1.16~1.21时,将由梁耗能向柱耗能转变;柱端拉筋强构造技术后,由于拉筋直接约束混凝土,大幅度提升了柱端抗弯承载力和耗能能力,组合节点在高轴压比时仍维持梁端失效破坏模式;根据《建筑抗震设计规范》,梁-柱抗弯承载力比取值小于1时为强柱弱梁,这对穿入式组合节点强柱弱梁的定义较为保守。
A seismic performance analysis of four concrete-filled steel tube columns is conducted with the weakened flanges and penetrated composite joints using three-dimensional solid finite element model.Besides the triaxial plastic damage of concrete and the isotropic-kinematic combined hardening model of steel tube,a ductile damage model of structural steel is introduced in the finite element analysis to accurately simulate the influence of steel beam weakening on the seismic behaviours and the failure mode of the joints.The results indicate that the proposed finite element model is more rational when comprised with the experimental observation.The effect of steel beam weakening reduces the stiffness,bearing capacity,and energy dissipation capacity of the joints.Meanwhile,the effects of the sizes of steel beam and column end reinforcing bars on the joint’s bearing capacity,stiffness,plastic energy dissipation allocation and failure mechanism were analyzed.The results show that when the ratio of the bending capacity,axial stiffness and the sectional stiffness of the beam and column ranges from 1.66 to 2.11,1.90 to 1.96 and 1.16 to 1.21,respectively,the major member of energy dissipation will shift from beam to the column in the penetrated joints.By setting stirrups at the column end,the bending capacity and energy dissipation of the joints were significantly improved due to the direct restraining of the concrete.The composite joints can maintain the beam end failure type even subjected to high axial compression.Hence in the Design Code,the ratio of the bending capacity of beam and column bending capacity ratio value is less than 1,which is a conservative definition for the strong column and weak beam penetrated joint.
作者
徐庆元
雷建雄
丁发兴
周期石
张华帅
邱远光
杨建军
XU Qing-yuan;LEI Jian-xiong;DING Fa-xing;ZHOU Qi-shi;ZHANG Hua-shuai;QIU Yuan-guang;YANG Jian-jun(School of Civil Engineering,Central South University,Changsha,Hu’nan 410075,China;China Railway Urban Construction Group Co.,Ltd.,Changsha,Hu’nan 410075,China;The 1st Engineering Co Ltd of China Railway Urban Construction,Changsha,Hu’nan 410075,China)
出处
《工程力学》
北大核心
2025年第1期116-128,共13页
Engineering Mechanics
基金
国家自然科学基金项目(51978664,51978673)。
关键词
方钢管混凝土柱
钢-混凝土组合梁
穿入式组合节点
韧性损伤
塑性耗能
concrete-filled square tubular column
steel-concrete composite beam
penetrated composite joints
ductile damage
plastic energy dissipation capacity
