Development of Damage-Resislient Structures Using Smart Materials

基于力和基于性能的抗震设计方法将目标最大漂移作为性能水平和损坏的指标。震后侦察观测进一步确定了剩余漂移作为量化结构性能和结构运行状态的措施的额外重要性。因此，残余的漂移决定了一个结构是否可以使用，是否需要修复，或者是否必须拆除。本研究的总体目标是开发有弹性的混凝土结构系统，用智能材料加固或改造，以控制在地震激励下产生的永久性损伤，从而使结构立即可用。形状记忆合金（sma）是一类具有控制永久变形能力的智能材料。该材料具有承受大应变的能力，在钢筋中会引起显著的永久应变，但具有在去除应力（超弹性（SE） SMA）或应用热（形状记忆效应（SME））后恢复其原始形状的优越能力。这是使该材料在地震应用中具有吸引力的主要行为特征。其他显著特征包括强度和位移能力可与钢筋相媲美，除了稳定的滞后响应。

Force-based and performance-based seismic design approaches specify target maximum drifts as indicators of performance level and damage. Post-earthquake reconnaissance observations have further identified the additional importance of residual drift as a measure to quantify structural performance and the operational state of a structure. The residual drift, therefore, determines whether a structure can be serviceable, requires repair, or must be demolished. The overarching goal of this research is to develop resilient concrete structural systems, reinforced or retrofitted with smart materials, to control permanent damage that arises during response to seismic excitations leading to structures that are immediately serviceable. Shape Memory Alloys (SMAs) are one class of smart materials that have the ability to control permanent deformations. The material has the capacity to sustain large strains, levels that would induce significant permanent straining in steel reinforcement, but with the superior capability to return to its original shape after removal of stress (Superelastic (SE) SMA) or with the application of heat (Shape Memory Effect (SME)). This is the main behavioural feature that makes the material attractive in seismic applications. Other salient characteristics include strength and displacement capacities comparable to steel reinforcement, in addition to stable hysteretic response.