新型卷边PEC柱-钢梁部分自复位连接组合框架结构体系抗震机理与设计对策

Self-centering structural systems have PT strands which run parallel to the beams,column or concrete wall and are anchored at the exterior columns or foundation, and an energy dissipation (ED) device such as top-and-seat angles, or friction devices,which posttensioning bars provide restoring force and self-centering behavior that reduces the potential for residual drift and alleviates struactural damage process,while energy dissipation elements can be used to dissipate earthquake energy and reduce the structural response.they have the potential to avoid the costly and intrusive post-earthquake repair of the major structural elements by confining the damage to the ED device, which is easily replaced. Up to date, research achievements of SC structures is not abundant abroad and more deficient at home. In order to eliminate the negative influence resulted from stress relaxation of PT strands, and achieve unification and harmonization in self-centering function, energy-dissipation and the safety redundancy of structure, new type crimping PEC column-steel beam composite frame structural systems with partial self-centering connection are put forward to investigate its seismic mechanism and design strategy.Firstly a series of experiments will be conducted to study its self-centering function, energy dissipation style, force-interferring mechanism of partial self-centering connection ,failural mode and collapse mechanism.Secondly the existing FE software will be adopt to develop further to build the FEA models of partial self-centering connection and relevant composite frame structural systems that the nolinearity of material, geometry and boundary condition should be taken into account,and then they will be validated and improved by the tests results and further be utilized to analyze the effects of various design parameters on the mechaical performance of connections and structural systems.Finally,seismic design strategy and construction details will be proposed on the basis of the performance design objective.The research achivements will provide theoretical basis for engineering application of the structural systems,which will be of great theoretical significance and soundly practical application prospects.

自复位结构即在梁、柱或墙上增设预拉杆与辅助耗能元件，以实现结构震后自行复位、残余变形明显减小、延缓结构主要受力构件损伤进程、保证结构耗散地震能能力，从而达到结构预定性态设计目标和震后修复成本降低。迄今为止，国外自复位结构研究系统，而国内相关成果缺乏。 为减小预应力筋松弛带来的不利影响和更好实现结构自复位功能、耗能能力与结构安全冗余度的协调统一，课题组提出了本项目"新型卷边PEC 柱-钢梁部分自复位连接组合框架结构体系的抗震机理与设计对策"。通过试验研究其自复位功效、耗能模式、部分自复位连接传力模式、结构层间倒塌机理与破坏模态；利用商业有限元软件进行二次开发，构建相应组合框架结构体系数值分析模型，系统分析各设计参数对连接节点与组合框架结构体系抗震性能的影响规律；基于试验和模拟结果，提出抗震设计对策与构造措施。研究成果将为该结构体系的工程应用奠定基础，有重要理论意义和良好的应用前景。

自复位结构即在梁、柱或墙上增设预拉杆与辅助耗能元件，以实现结构震后自行复位、残余变形明显减小、延缓结构主要受力构件损伤进程、保证结构耗散地震能能力，从而达到结构预定性态设计目标和震后修复成本降低。.为减小预应力筋松弛带来的不利影响和更好实现结构自复位功能、耗能能力与结构安全冗余度的协调统一，课题组提出了有机协调自复位、耗能和结构安全冗余度三者关系的部分自复位连接形式和设计理念。本项目主要针对新型PEC柱-钢梁部分自复位连接和相应组合框架结构抗震性能与设计对策进行研究，主要研究包括：4个PEC柱-钢梁框架中节点部分自复位连接试件进行了试验研究和有限元模拟，得到了滞回曲线，通过对试验与模拟分析得出其相关设计参数（柱钢结构组合截面强弱轴布置、耗能件形式（摩擦型和BRS板耗能）、预应力大小）对其承载力、抗侧刚度、自复位功效和耗能能力的影响规律；6个PEC柱-钢梁框架边节点部分自复位连接1：1.6缩尺试件进行了试验研究和相关系列有限元模拟，得到了滞回曲线，通过对试验与模拟分析得出设计参数（柱钢结构组合截面强弱轴布置、耗能件（摩擦型和BRS耗能板）、柱子竖向力）对其承载力、抗侧刚度、自复位功效和耗能能力的影响规律；12榀PEC柱-钢梁常规连接框架中间层子结构和两层框架结构试件进行了循环荷载试验研究和数值模拟，得到了其滞回曲线和破坏模态，通过试验与模拟分析得出设计参数（PEC柱卷边/非卷边、PEC柱的强弱轴布置、梁柱连接方式）对其承载能力、抗弯刚度、耗能延性与抗震机理的影响规律；近期完成6榀PEC柱-钢梁部分自复位连接框架中间层子结构1：2试件进行了循环荷载试验研究和数值模拟，得到了其滞回曲线，通过数据整理分析得出其相关设计参数（预拉杆的构造（通长与部分长度）、耗能件形式（摩擦型和BRS耗能板）、预应力大小、PEC柱卷边/非卷边、PEC柱的强弱轴布置，简单修复等）对其承载力、抗侧刚度、自复位功效、耗能能力和抗震修复性的影响规律。以上研究成果已经发表和收录论文约32篇。.此外，由于课题组实验室的安排，相应延缓组合框架结构层面的研究工作进程，后续工作计划在2019年完成。随着项目全部研究内容的完成，研究成果将会进一步丰富，也为新型PEC柱-钢梁部分自复位连接相关结构的进一步研究和工程应用奠定理论基础和技术支撑。