SummaryThe response of tall buildings to wind actions is commonly assessed through the quasi‐static approach considering mean, background, and resonant components of the action. The latter accounts for the amplification due to resonance and depends on the dynamic properties of the buildings, that is, modal mass, frequency, and damping ratio. Selecting appropriate values of the modal parameters of tall buildings is not immediate and is usually done using predictive models. These contain uncertainty, which eventually propagates to the dynamic response. The main aim of the paper is the assessment of uncertainty in the dynamic response of flexible buildings to wind action arising from a not perfect knowledge of their dynamic properties. The paper explicitly refers to the dynamic models given by Eurocode 1, but the approach is general, and the analyses can be repeated selecting any other model. It is found that the bias in the dynamic factor is always less than one, with values on average between 0.86 and 0.98. This indicates that the approach of Eurocode 1 is conservative. The only exception is that of the acrosswind response of steel buildings with an high aspect ratio, in which case the bias can be as large as 1.16. As to randomness, the coefficient of variation of the alongwind dynamic factor is very seldom found to exceed 10%, with average values around 5%. Such values are much lower than those of the coefficient of variation of damping, which is in the order of 50% or more. This indicates that uncertainty attenuates when it propagates to the response. On the other hand, the coefficient of variation of the acrosswind and torsional dynamic factors reaches values of 20% or more, indicating that such attenuation is much lower in that case.

中文翻译：

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高层建筑动力特性的不确定性和风致响应的传播

摘要高层建筑对风作用的响应通常通过准静态方法进行评估，考虑作用的平均、背景和共振分量。后者考虑了由于共振引起的放大，并且取决于建筑物的动态特性，即模态质量、频率和阻尼比。选择高层建筑模态参数的适当值并不是立竿见影的，通常是使用预测模型来完成的。这些包含不确定性，最终传播到动态响应。本文的主要目的是评估柔性建筑对风作用的动态响应的不确定性，这是由于对其动态特性的不完全了解而产生的。本文明确引用了欧洲规范1给出的动态模型，但方法是通用的，并且可以选择任何其他模型重复分析。结果发现，动态因子的偏差始终小于 1，平均值在 0.86 至 0.98 之间。这表明欧洲规范 1 的方法是保守的。唯一的例外是高纵横比钢结构建筑的侧风响应，在这种情况下偏差可能高达 1.16。从随机性来看，顺风动力因子的变异系数很少超过10%，平均值约为 5%。这些值远低于阻尼变异系数的值，约为 50%或者更多。这表明不确定性在传播到响应时会减弱。另一方面，侧风和扭转动力因素的变异系数达到20%或更多，表明在这种情况下这种衰减要低得多。