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Instantaneous wind pressures on the wall of structures by the sudden change of wind direction

风向突变对建筑物壁产生的瞬时风压

基本信息

批准号：
15206062
负责人：
TANIIKE Yoshihito
金额：
$ 28.04万
依托单位：
Osaka City University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2006
项目状态：
已结题

项目摘要

A lot of dispersions and dropouts of claddings of the pane and the roof cladding subject, etc. have been generated though it is not possible to destroy with the large structure. In many cases, the wind loading for the design of these claddings is evaluated based on the experiment and the analytical result when the wind direction is constant. However, the wind force when the change in a rapid wind direction is accompanied is not necessarily included by the experimental result when the wind direction is constant. This research aimed to examine the spatial structure in the strong wind with a wind direction change, and to clarify properties of the local wind pressure on the large models.The wind direction variation character of natural wind was examined, and it proposed the idea of "Wind direction change section". By using this idea, "Rapid wind direction change" was shown as the phenomenon that the wind run in the "Wind direction change section" was small. Moreover, the wind pressure characteristics of the building exterior material by a momentary wind direction change were examined by the field measurement. As a result, when the instantaneousness of the wind direction change was high, it was confirmed might cause a big negative pressure. In addition, it proposed the method of evaluating the stability index of the wind direction in natural wind by the linearity of natural wind. It was shown to be able to select data with high generality by using this technique according to the wind direction stability. From the field measurement data concerning the surface wind pressure of the cylinder structure with high wind direction stability, it was shown that there was a possibility that the turbulence of the approach wind causes making of the decrease in the critical Reynolds number.

虽然不可能与大型结构一起破坏，但已产生了窗格和屋顶覆层主体等的覆层的大量分散和脱落。在许多情况下，这些包层设计的风荷载是根据试验和分析结果在风向不变的情况下评估的。然而，当风向恒定时，实验结果不一定包括当风向快速变化时的风力。本研究旨在探讨强风风向变化下的空间结构，阐明大型模型局部风压的特性，探讨自然风的风向变化特征，提出“风向变化段”的概念。利用这一思想，将“风向突变”表现为“风向突变段”的风速偏小的现象。此外，通过现场实测，研究了建筑外墙材料在瞬间风向变化时的风压特性。结果，当风向变化的瞬时性高时，确认可能会引起大的负压。提出了利用自然风的线性度来评价自然风中风向稳定性指标的方法。结果表明，该方法可以根据风向稳定度选择通用性强的数据。通过对高风向稳定性圆柱结构表面风压的实测数据分析，表明了近场风的湍流作用可能导致临界雷诺数的降低。