新型自密实混凝土加固震损RC框架节点低周反复试验数值模拟

Numerical simulation for pseudo-static test of earthquake-damaged RC frame joints strengthened by self compacting concrete

在前期节点加固试验研究基础上,运用有限元Opensees程序软件对试验进行仿真模拟.提出了节点损伤分区的概念,将节点的震损分为梁柱端部损伤区和节点核心损伤区两部分并差别处理;结合梁柱节点单元的特点,提出使用面积加权平均的方法计算加固后震损RC框架节点核心区平均受剪应力-应变关系;同时提出将柱子损伤模型推广应用到节点时对损伤D值折减的方法.结果表明模拟滞回曲线与试验曲线符合较好,建立的加固震损RC框架节点有限元模型可以较准确地模拟试验试件在低周反复荷载下的受力变形性能,为进一步理论分析奠定基础.

In this paper, the previous experimental study is simulated using the finite element software Opensees. The conception of joint damage partition is presented, which divides the seismic damage into beam column end damage zone and joint core damage zone being treated differently. According to the characteristics of Beam Column Joint Element, the Area Weighted Average method is proposed to get the average shear stress-strain relationship in the core area of the damaged RC frame joints. At the same time, it is concluded that the damage D value should be reduced when applying the Column-Damage-Model to the joints. The results show that the simulation results stay in good agreement with the experimental results, and the finite element model of the strengthened RC frame joints with seismic damage in this paper can be used to simulate the deformation behavior of the specimen under low cyclic loading, and it lays the foundation for the further theoretical analysis.