Condition identification of bolted connections using a virtual viscous damper
Condition identification of bolted connections using a virtual viscous damper
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DOI：
10.1177/14759217211009217
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发表时间：
2021-05
期刊：
影响因子：
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通讯作者：
S. Biswal;M. Chryssanthopoulos;Ying Wang
中科院分区：
文献类型：
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作者：
S. Biswal;M. Chryssanthopoulos;Ying Wang
基于振动的螺栓连接状态识别有助于钢结构的有效维护和运行。已有的研究表明，模态参数对预紧力损失等损伤不敏感。相反，时域中的结构响应包含关于结构系统的所有信息。因此，本研究的目的是利用时域数据直接螺栓连接的状态识别。基于钢框架的振动测试数据，采用不同的螺栓组合和预紧力损失，代表不同的损伤情况，进行有限元模型修正。结果表明，钢框架的数值模拟加速度响应与实测加速度响应之间无法实现匹配。这是因为在钢框架的动力激励下，螺栓连接产生了时变非线性。为了捕捉非线性，虚拟粘滞阻尼器的建议。通过使用所提出的阻尼器旁边的有限元模型的更新系统矩阵，时域加速度响应估计与实测响应具有很大的一致性。结果表明，所提出的虚拟阻尼器不仅是有效的，在估计时域加速度响应在每个损伤的情况下，但也有可能的螺栓连接的状态识别这样的小损伤，只有一个螺栓与损失的预紧力。它也可以应用于其他具有挑战性的情况下的状态识别，其中模态参数是不敏感的损伤。
Vibration-based condition identification of bolted connections can benefit the effective maintenance and operation of steel structures. Existing studies show that modal parameters are not sensitive to such damage as loss of preload. In contrast, structural responses in the time domain contain all the information regarding a structural system. Therefore, this study aims to exploit time-domain data directly for condition identification of bolted connection. Finite element model updating is carried out based on the vibration test data of a steel frame, with various combinations of bolts with loss of preload, representing different damage scenarios. It is shown that the match between the numerically simulated and measured acceleration responses of the steel frame cannot be achieved. The reason is that time-dependent nonlinearity is generated in bolted connections during dynamic excitation of the steel frame. To capture the nonlinearity, a virtual viscous damper is proposed. By using the proposed damper alongside the updated system matrices of the finite element model, the time-domain acceleration responses are estimated with great consistency with the measured responses. The results demonstrate that the proposed virtual damper is not only effective in estimating the time-domain acceleration responses in each damage case, but also has the potential for condition identification of bolted connections with such small damage as just one bolt with loss of preload. It can also be applied to other challenging scenarios of condition identification, where modal parameters are not sensitive to the damage.