基于形状记忆合金的高性能自回复框架结构的抗震性能与抗震设计

The Wenchuan Earthquake in southwest China caused great casualties and inflicted severe damage to cities and towns. Such a devastating earthquake arouses the national-wide awareness of the importance of structural safety and earthquake hazard mitigation technology. Facing the arduous post-disaster missions (e.g. rescue, salvation, and medical treatment), the safety and functionality of a few critical civil infrastructures such as hospitals becomes highly significant in such extreme situations.. .This project aims to develop a new type of high-performance seismic resisting structural system. A novel bracing element, termed SMA-based self-centering damping brace (SSCDB), has been recently proposed by the PI and his co-workers. This special type of bracing devices utilizes one smart material-shape memory alloy-as its core component. The preliminary study indicated that the framed building with these new bracing devices can overcome the problems of conventionally concentrically braced frame and buckling-restrained braced frames. For example, this new type of braced frames has significantly reduced permanent deformation after strong earthquakes, and it can withstand several strong earthquakes with no need for repair or replacement. These salient features can avoid costly repair and minimize the downtime after earthquakes, and thus achieve a relatively economic design in terms of life-cycle cost. Moreover, the ability to withstand a number of potential significant aftershocks makes it an appealing structural system to those safety-critical buildings such as hospitals, emergency management agency, communication facilities, buildings for national defense, etc, in which incessant operation after a catastrophic earthquake is always desired...However, many questions still remain unanswered with regard to the development of this promising seismic resisting structural system towards real applications. The goal of this project is to address this knowledge gap through an in-depth analytical and experimental study of this new type of high-performance framed buildings. Key factors related to this bracing element will be carefully investigated; a practical design methodology will be developed in order to facilitate its implementation in real buildings; the seismic performance of this novel framed building system will be validated through a series of shaking table experiments. The outcome of this project will provide an appealing alternative technology for earthquake hazard mitigation of critical building structures.

频发的大地震造成了严重的破坏及伤亡，引起了对抗震安全和抗震技术的广泛关注。本项目旨在研发一种新型的基于自回复阻尼支撑的高性能抗震结构体系。申请人于近期提出一种全新的支撑构件，它合理运用了形状记忆合金的多种优良特性。与传统的斜支撑框架体系和防屈曲支撑体系相比，这种框架体系具有若干显著的优势，例如极小的震后永久变形、承受多次强震的能力等。它可以降低昂贵的维修费用和漫长的维修时间，同时确保结构在频繁余震下的安全性，在地震高风险区是一种理想的高性能抗震体系，同时从全寿命的角度考虑也是一个经济的选择。对许多重要的建筑物如医疗、通讯、应急中心等，这将是显著的抗震性能优势。然而，如何将这种极具潜力的抗震结构体系应用到实际工程中，仍然还有许多问题亟需解决。本项目的目标是通过系统的理论分析、试验研究，全面了解这种自回复框架的抗震性能和未解决的相关技术问题，并提出一个实用的设计方法以便在真正的建筑结构中实施。

鉴于频发的大地震所造成的严重破坏及伤亡，本项目研究了一种新型的基于自回复阻尼支撑的高性能抗震框架结构体系。该自回复支撑是一种全新的基于形状记忆合金的支撑构件，充分运用了形状记忆合金的超弹性、高疲劳寿命、耐腐蚀等多种优良特性。与传统的斜支撑框架体系相比，这种自回复支撑框架体系具有显著的抗震性能优势，例如稳定的滞回特性、极小的震后永久变形、承受多次强震的能力等。因此它可以最大限度地降低震后的维修费用和维修时间，同时确保结构在频繁余震下的安全性，在地震高发区是一种理想的高性能抗震体系，同时从全寿命的角度考虑也是一个经济的选择。对许多重要的建筑物如医疗、军事、通讯、应急中心等，这些抗震优势都有着十分重要的意义。为全面掌握并验证这种新型的抗震结构体系的性能优势，本项目开展了系统的理论分析、试验研究，并有针对性的解决了以下相关的技术问题：1. 评估了不同种类的形状记忆合金在地震工程中的适用性；2. 基于超弹性形状记忆合金的本构模型，进行了精确的自回复框架的地震响应数值模拟；3. 针对自回复框架的结构特性，提出了一种有针对性的基于性能的抗震设计方法；4. 通过一系列振动台试验，验证了所提出的自回复框架体系的优越性及可行性。本项目严格按照计划执行，进展情况顺利。在本基金的资助下，至项目结题时为止，已发表了4篇SCI期刊论文，另有2篇SCI期刊论文在审稿中。