Structural damage caused by mainshock can further be aggravated by aftershocks, which can lead to structural collapse. The current practices on the seismic design of structures generally only consider mainshock effects. This manuscript therefore presents the investigation on damage-based yield point spectra (YPS) of a single-degree-of-freedom (SDOF) system under sequential earthquakes. The collected sequence-type ground motions are recorded from 16 earthquake events and classified to four classes. The aftershocks in sequence are scaled according to different relative intensity levels. The modified Park-Ang model, which consists of maximum displacement and hysteretic energy dissipation, is employed to calculate YPS. The effects of period, ductility factor, damage index, site category, aftershock intensity, and structural damping are statistically studied. The results prove that the strong aftershock ground motion has more distinct influences on the YPS. In particular, the yield strength coefficient demand under seismic sequence increases by 10%–50%. The yield strength coefficient demand determined by the damage-based YPS is greater than that determined by the ductility-based YPS—the former is 10%–40% higher than the latter. Finally, the empirical expression of damage-based YPS is established by statistical mean method and regression analysis.

中文翻译：

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基于损伤的屈服点谱，用于序列型地面运动

余震会进一步加剧由主震造成的结构破坏，从而导致结构倒塌。结构抗震设计的现行做法通常只考虑主冲击效应。因此，该手稿提出了对连续地震下单自由度（SDOF）系统基于损伤的屈服点谱（YPS）的研究。从16个地震事件中记录了收集的序列型地震动，并将其分为四类。根据不同的相对强度水平按顺序缩放余震。修改后的Park-Ang模型由最大位移和滞回能量耗散组成，用于计算YPS。周期，延性因子，破坏指数，场地类别，余震强度，对结构阻尼进行了统计研究。结果表明，强余震地震动对YPS的影响更大。特别是，地震序列下的屈服强度系数需求增加了10％–50％。基于损伤的YPS确定的屈服强度系数需求大于基于延性的YPS确定的屈服强度系数需求，前者比后者高10％–40％。最后，通过统计均值法和回归分析建立了基于损伤的YPS的经验表达。基于损伤的YPS确定的屈服强度系数需求大于基于延性的YPS确定的屈服强度系数需求，前者比后者高10％–40％。最后，通过统计均值法和回归分析建立了基于损伤的YPS的经验表达。基于损伤的YPS确定的屈服强度系数需求大于基于延性的YPS确定的屈服强度系数需求，前者比后者高10％–40％。最后，通过统计均值法和回归分析建立了基于损伤的YPS的经验表达。