Abstract This study presents a methodology to generate probabilistic seismic demand models and hazard curves for steel frames with or without shape memory alloy (SMA) bracing systems under mainshock – aftershock sequences. First, three post-mainshock damage states were defined based on both peak inter-story drift and residual drift ratios. Incremental dynamic analyses (IDA) were performed considering only mainshock events to determine spectral acceleration demands corresponding to each mainshock damage level. Then, aftershock IDA were conducted on the post-mainshock SMRF and SMA frames at three damage states. To estimate the peak and residual drift response of SMRF and SMA braced frames subjected to a mainshock – aftershock sequence, empirical seismic demand models were developed. Next, a risk-based seismic performance evaluation study was conducted to generate seismic demand hazard curves for maximum and residual interstory displacement response. Results reveal the advantages of SMA braces in enhancing post-event functionality of steel frame buildings. In addition, defining damage states based on residual drifts is recommended while comparing the aftershock performance of conventional steel moment resisting frames with self-centering steel buildings.

中文翻译：

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基于风险的SMA支撑钢框架主余震性能评估

摘要 本研究提出了一种在主震-余震序列下为带或不带形状记忆合金 (SMA) 支撑系统的钢框架生成概率地震需求模型和危险曲线的方法。首先，根据峰值层间漂移和残余漂移比定义了三种主震后损坏状态。增量动态分析 (IDA) 仅考虑主震事件，以确定对应于每个主震损坏级别的谱加速度需求。然后，对主震后 SMRF 和 SMA 框架在三种损伤状态下进行余震 IDA。为了估计 SMRF 和 SMA 支撑框架在主震 - 余震序列下的峰值和残余漂移响应，开发了经验地震需求模型。下一个，进行了一项基于风险的地震性能评估研究，以生成最大和剩余层间位移响应的地震需求危险曲线。结果揭示了 SMA 支撑在增强钢框架建筑事后功能方面的优势。此外，在比较传统钢结构抗矩框架与自定心钢结构建筑的余震性能时，建议根据残余漂移定义损坏状态。