Self-Centering Concrete Structures Using Smart Materials

根据现行抗震规范设计的结构的主要性能标准是避免生命损失和防止结构倒塌。大多数结构在满足主要标准的情况下，在大地震事件期间将经历损坏。这将导致大量的维修时间，或者在过度损坏的情况下对建筑物业主造成经济后果时进行拆除。作为回应，研究已经导致了自定心技术的发展，以限制永久性损坏。此外，温哥华、维多利亚、多伦多、渥太华、蒙特利尔和魁北克市的大量建筑物是在20世纪70年代之前建造的，根据目前对地震需求的估计，这些建筑物在地震方面很脆弱。已经制定了一些方法，用于全球系统恢复或局部元件改造，以改善有缺陷的结构的性能。近年来形状记忆合金的出现为新型和现有结构的自定心结构系统的开发提供了机会。SMA可以承受显著的非弹性变形，并且在去除应力后能够恢复到其原始未变形形状。其他突出的特点包括强度和位移能力，相当于钢筋，除了稳定的滞回响应和足够的能量耗散能力。 本研究计划的目的是开发自定心技术作为一种缓解策略，混凝土结构受到地震荷载，通过利用SMA的显着特点。滞后本构模型将开发非线性数值工具，而大规模的测试将调查钢筋混凝土剪力墙加固或SMA改造的新建筑和抗震性能差的现有结构的行为。还将制定设计程序。

The primary performance criterion for structures designed with current seismic codes is to avoid loss of life and prevent structural collapse. Most structures will experience damage during large seismic events while satisfying the primary criterion. This will result in either significant downtime for repairing or demolition in the event of excessive damage posing economic consequences for building owners. In response, research has led to the development of self-centering technologies to limit permanent damage. In addition, a significant percentage of building stock in Vancouver, Victoria, Toronto, Ottawa, Montreal, and Quebec City was constructed prior to the 1970s, and it is seismically vulnerable to current estimates of seismic demand. A number of methodologies have been developed for global system rehabilitation or local element retrofitting to improve performance of deficient structures. The recent emergence of Shape Memory Alloys (SMAs) provides an opportunity to develop novel self-centering structural systems for new and existing structures. SMAs can sustain significant inelastic deformations with the capacity to return to its original undeformed shape after removal of stress. Other salient characteristics include strength and displacement capacities that are comparable to that of steel reinforcement, in addition to stable hysteretic response and sufficient energy dissipation capacity. The objective of this research program is to develop self-centering technologies as a mitigation strategy for concrete structures subjected to earthquake loading by exploiting the salient features of SMAs. Hysteretic constitutive models will be developed for nonlinear numerical tools, while large-scale testing will investigate the behaviour of reinforced concrete shear walls reinforced or retrofitted with SMAs for new construction and seismically deficient existing structures. Design procedures will also be developed.