高强钢筋高延性纤维增强混凝土框架结构的屈服机制和抗震性能

为了对混凝土框架结构的地震破坏机制和抗震性能进行控制,在框架柱中配置高强钢筋,并将纤维增强混凝土(FRC)用于框架结构的预期损伤部位。结构柱中的高强钢筋用来减小结构的残余变形,FRC材料用来增加结构的耗能能力和损伤容限。设计了三个框架,采用动力弹塑性时程分析方法进行分析。研究结果表明,采用高强钢筋提高了结构的整体承载能力,在层间侧移角达到3%之前避免了柱铰的出现(包括底层柱底),并且减小了结构的残余变形;预期损伤部位采用FRC材料能够提高结构的塑性耗能。

Yielding Mechanism and Seismic Performance of Frame Structure with High-strength Bars and High-ductile Fiber-reinforced Concrete

To control the failure mechanism and seismic performance of reinforced concrete (RC) frame structures,our proposed system used ultra-high-strength (UHS) reinforcement in a column and had the option of using fiber-reinforced concrete (FRC) in a frame where damage is expected to occur.Disaster investigations revealed that reinforced concrete frame structures account for a high proportion of buildings destroyed.The use of UHS reinforcement was expected to result in only minimal residual deformations and a low degree of hysteretic energy dissipation.FRC was expected to facilitate hysteretic energy dissipation and increase the system''s damage tolerance.Using nonlinear time history analysis,we investigated three frame structures using ABAQUS finite element software,a large universal finite element software widely used in the nonlinear analysis of RC structures.In particular,we used the concrete-damaged plasticity model,which is one of the most important concrete constitutive models in ABAQUS.Based on our analysis results,we discussed the seismic behavior of structures at different seismic intensities.To determine the seismic capacity of each structure,we selected the following parameters: maximum deformation,story drift,residual deformation,and energy dissipation.We found that the use of UHS reinforcement provided the system with relatively greater resistance against lateral seismic loads and resulted in less residual deformation while preventing the critical column from yielding until the drift reached 3%~4%.Thus,UHS frames should be used in columns designed for a "strong column-weak beam" failure mechanism.As the drift increased,differences in residual deformation between specimens decreased.These research results suggest that the proposed system may be promising for improving the damage tolerance of structures in seismic regions.