Recent studies have indicated the need of considering aftershocks in the seismic design/assessment of structures. This article investigates the effect of sequential mainshock and aftershock earthquakes on eccentrically braced steel frames with vertical energy-absorbing links. To achieve this, 4, 8 and 12-storey frame buildings are modelled in Perform3D® software considering non-linear behaviour of materials and components. The frames are subjected to a set of 12 main earthquake records corresponding to the required hazard level, and then subsequent aftershocks are applied using incremental dynamic analysis (IDA). To reduce the computational cost, an alternative approach is also adopted by applying the main earthquakes to the system followed by pushover analyses on the damaged building assuming a lateral load distribution proportional to the shape of the first vibration mode. Subsequently, the fragility curves are obtained for different damage levels, before and after the main earthquake. The results show that the eccentric braced frames with vertical links subjected to sequential earthquakes comply well with the performance levels of the Iranian Seismic Code. This study contributes toward the assessment and seismic validation of structures with eccentrically braced steel frames with vertical energy-absorbing links to sequential earthquakes.

最近的研究表明，在结构的抗震设计/评估中需要考虑余震。本文研究了连续主震和余震对垂直吸收能量的偏心支撑钢框架的影响。为此，考虑到材料和组件的非线性行为，在Perform3D®软件中对4层，8层和12层的框架建筑物进行建模。对框架进行12组与所需危险等级相对应的主要地震记录，然后使用增量动态分析（IDA）应用后续余震。为了降低计算成本，还采用了另一种方法，即对系统施加主要地震，然后对受损建筑物进行推覆分析，并假设其横向载荷分布与第一振动模式的形状成比例。随后，在主地震之前和之后，针对不同的破坏水平获得了脆性曲线。结果表明，具有垂直链环的偏心支撑框架经受连续地震的影响，符合伊朗《地震法》的性能标准。这项研究有助于偏心支撑钢框架结构的评估和地震验证，这些框架具有垂直吸收能量的连续地震。结果表明，具有垂直链环的偏心支撑框架经受连续地震的影响，符合伊朗《地震法》的性能标准。这项研究有助于偏心支撑钢框架结构的评估和地震验证，这些框架具有垂直吸收能量的连续地震。结果表明，具有垂直链环的偏心支撑框架经受连续地震的影响，符合伊朗《地震法》的性能标准。这项研究有助于偏心支撑钢框架结构的评估和地震验证，这些框架具有垂直吸收能量的连续地震。