基于SMA和滑移连接的新型自复位消能梁段抗震机理与设计方法研究

A four level seismic fortification objective of earthquake resilient structures was proposed as “no damage under minor and moderate earthquake, replaceable or repairable under major earthquake, and no collapse under mega earthquake”. To further improve the seismic performance and seismic resilience capacity of EBFs during earthquakes, ideal shear links are necessary to be capable of dissipating higher seismic energy with higher ductility and less damage and low residual deformation, so the EBFs can better meet the higher demand in modern code for seismic design of buildings. In this project, an innovative self-centering short shear link with SMA and sliding connection that has an advantage of high ductility, good energy dissipation capacity, low damage and low residual deformation is developed, which combines with the advantage of self-centering brace with SMA and low friction and short shear link with shear slotted bolted connection (SSL-SSBC).The working mechanism and mechanical behavior of self-centering brace with shape memory alloys (SMA) and low friction will be revealed in detail. Then based on the preliminary research achievements of the SSL-SSBC, the seismic mechanism of self-centering short shear link are carried out by using the experimental, FEM and theoretical methods, so the interaction and influence rule between the self-centering brace and SSL-SSBC will be clearly illustrated. Also, the failure mode, bearing capacity and hysteresis performance of self-centering short shear link in different seismic fortification targets can be obtained. With the above analysis, a mechanical model that can accurately reflect the mechanical property of the innovative self-centering short shear link is proposed, and the corresponding optimum design method is also established. It is expected that the seismic performance and seismic resilience capacity of the EBFs will be dramatically improved by using the proposed self-centering short shear link, and this research project can provide a new way to give important seismic design reference for the EBFs.

当前可恢复功能结构“小震及中震不坏，大震可换、可修复，巨震不倒塌”的四水准抗震设防目标被提出且日益被重视。偏心支撑结构需进一步增大消能梁段的延性和耗能能力以及减小消能梁段的损伤和残余变形，以使结构更好地适应当前要求。本项目结合SMA-低摩擦自复位支撑和扩孔螺栓连接型消能梁段的优点，提出一种基于SMA和滑移连接的高延性、强耗能、低损伤、低残余变形的新型自复位消能梁段。通过对自复位支撑的研究，可明确其工作机理和受力性能。结合前期对扩孔螺栓连接型消能梁段的研究成果，开展新型自复位消能梁段的试验、数值仿真和理论研究，阐明自复位支撑-扩孔螺栓连接型消能梁段的相互作用与影响规律，揭示自复位消能梁段的抗震机理与特点，明确不同抗震设防目标下的破坏模式、承载能力和滞回性能等，并提出其力学模型和建立相应的设计方法。该研究将有效提高偏心支撑结构的抗震性能和震后功能恢复能力，为该种结构的抗震设计提供新的方法。

当前国家日益重视建筑结构体系的抗震性能和震后功能快速恢复能力,偏心支撑结构需进一步提高耗能段的延性和耗能能力以及减小耗能段的损伤和残余变形。本文结合扩孔螺栓连接型耗能段和自复位SMA支撑的力学性能，提出一种基于SMA和滑移连接的新型自复位耗能段，具有高延性、强耗能、低损伤、低残余变形等特点。本文以研究基于自复位耗能段的偏心支撑钢框架结构的抗震性能，并建立结构的设计方法为目标。研究内容主要包括：1）完成10个SMA丝材试件的试验研究，分析应变幅值、加载速率和初始应变对其力学性能的影响，编制其数值模型并进行理论分析；2）完成6个自复位SMA支撑的试验研究，得到滞回曲线、骨架曲线、割线刚度、耗能、等效阻尼系数和自复位率等，并对其进行数值模拟分析；3）完成3个短剪切型耗能段的试验研究，得到其破坏模式、滞回曲线、割线刚度、耗能能力和等效黏滞阻尼系数等，并开展参数化分析，阐明不同因素下短剪切型耗能段的承载能力；4）开展13个剪切扩孔型螺栓连接试件的研究，分析结果应用于4个扩孔螺栓连接型耗能段试件中，并开展相应试验、有限元和理论分析，分析其破坏模式、滞回性能和力学模型，建立相应的设计方法；5）完成4个自复位耗能段的试验研究，并开展有限元参数化分析和理论研究，明确自复位耗能段的力学性能，阐明自复位SMA支撑与扩孔螺栓连接型耗能段的相互作用与影响规律，并建立其设计方法；6）研究基于自复位SMA支撑、基于短剪切型耗能段、基于扩孔螺栓连接型耗能段和基于自复位耗能段的偏心支撑钢框架结构的抗震性能，阐述各种结构在不同地震下抗震性能与特点，并评价基于自复位耗能段的偏心支撑钢框架结构的优点及性能。