非高斯风场作用下大跨桥梁极值响应研究

Extreme response of large-span bridges under non-Gaussian wind field

  • 摘要: 以某大跨桥梁为例,通过时域分析,得到了不同非高斯特性脉动风场作用下的抖振响应。基于ACER方法,开展了结构响应的短期和长期极值分析。结果表明:当风场的非高斯特性增强时,同一平均风速下的短期位移极值增加,且不同重现期对应的短期位移极值差异变大。相同条件下,长期位移极值高于短期位移极值,且随风场非高斯特性的增强,长期位移极值较短期位移极值的增长幅度上升。因此,相比高斯风场,非高斯风场作用下的桥梁位移极值更大,且更有必要考虑长期的影响。

     

    Abstract: According to an example of a large-span bridge, the buffeting responses under fluctuating wind field with different non-Gaussian feature are obtained through the time-domain analysis. Based ACER method, the analysis of the short-term and long-term extreme value for structural responses is conducted. Results show that when the non-Gaussian feature of wind field becomes stronger, the short-term extremal displacement will be larger under the same mean wind speed, and the difference of the short-term extremal displacements with various mean recurrence intervals will increase. Under the same condition, the long-term extremal displacement is larger than the short-term counterpart. In addition, under stronger non-Gaussian feature of wind field, the extent of the growth between the long-term extremal displacements and the short-term counterparts rises. Hence, compared with Gaussian wind field, the extremal displacement of bridges is larger under non-Gaussian wind field, and it is more necessary to consider the effect of the long term.

     

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