考虑嵌固端约束作用的RC柱纤维单元模型研究  

Study on Fiber Element Model of RC Column Considering Fixed End Restraints

作　　者：王璐 王秋维[1,2] 赵航 WANG Lu;WANG Qiuwei;ZHAO Hang(School of Civil Engineering,Xi’an University of Architecture&Technology,Xi’an 710055,China;Key Laboratory of Structural Engineering and Earthquake Resistance of Ministry of Education(Xi’an University of Architecture&Technology),Xi’an 710055,China)

机构地区：[1]西安建筑科技大学土木工程学院,陕西西安710055 [2]结构工程与抗震教育部重点实验室(西安建筑科技大学),陕西西安710055

出　　处：《湖南大学学报（自然科学版）》2023年第3期80-91,共12页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51878543,51878540);陕西省教育厅自然专项项目(21JK0733)。

摘　　要：针对传统纤维单元未考虑嵌固端约束作用而导致钢筋混凝土(RC)柱的数值模拟精度降低问题,分析了嵌固端约束作用对RC柱破坏形态和传统纤维单元模拟精度的影响.选取文献中45根高剪跨比RC柱并建立实体单元模型进行数值模拟,结果表明建模方法合理可靠;进而剖析了嵌固端约束机理及嵌固端约束作用对RC柱承载力和延性性能的影响,明确了控制截面位置及其承载力计算方法,阐明了纤维单元数值积分点位置与控制截面位置、权系数与等效塑性铰长度的对应关系,提出控制截面位置计算公式和考虑嵌固端约束影响的等效塑性铰长度计算公式,建立了一种考虑固端约束影响的纤维单元模拟方法.通过对文献中45根RC试验柱的数值模拟分析,表明所提方法可合理考虑嵌固端约束影响,具有较好的适用性.The traditional fiber element does not consider the constraint of the fixed end,which leads to the reduction of numerical simulation accuracy of reinforced concrete(RC)columns.The impact of the fixed end constraint on the damage pattern of RC columns and the simulation accuracy of the fiber unit was analyzed.45 RC columns with a high shear span ratio in the literature were selected and the solid element models were established for numerical simulation.The results show that the modeling method is reasonable and reliable.The restraint mechanism of the fixed end and the influence of the restraint effect of the fixed end on the bearing capacity and ductility of RC columns were then explained.The control section position and its load-carrying capacity calculation method were defined,and the corresponding relation between the numerical integration point position and the control section position,and between the weight coefficient and the equivalent plastic hinge length was clarified.Finally,the formula for calculating the control section position and the equivalent plastic hinge length considering the influence of the fixed end constraint was proposed,and a fiber element simulation method considering the influence of the fixed end constraints was built.Through the numerical simulation analysis of 45 RC test columns in the literature,it is shown that the proposed method can reasonably consider the influence of fixed end constraints and has good applicability.

关 键 词：钢筋混凝土柱 嵌固端约束 纤维单元 控制截面 等效塑性铰长度 数值模拟 

分 类 号：TU398[建筑科学—结构工程]