Reponse of a building induced by an abrupt gust

突然阵风引起的建筑物的响应

基本信息

批准号：
08650682
负责人：
KAWAI Hiromasa
金额：
$ 1.22万
依托单位：
Tokyo Denki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08650682/
关键词：
Gust wind loads Gust response Wind tunnel test Time series analysis Transition response Over shoot phenomena Linear model Ramdom pulse 過渡現象非線形現状風荷重過渡応答非定常性空力アドミッタンス核関数建築基準法

项目摘要

Buildings and houses are often damaged by an abrupt gust during a typhoon wind. Wind speed suddenly increase to double or three times of the mean wind speed and then decrease gradually in several seconds in such a gust. However, wind load induced by such a abrupt gust is not described in codes of practice in which it is assumed that wind blows stationary in a relatively long time. ln this research, characteristics of the wind load induced by the abrupt gust are investigated by wind tunnel tests and responses of buildings during the gust are investigated by numerical analysis in time series mainly from the following two points of view, 1) To simulate an abrupt gust in a wind tunnel, 2) To clarify a mechanism of a wind loading due to the gust, 3) To make model gust gust loads, 4) And to calculate the response of building induced by the model gust load.In order to simulate the gust, we set a fence at a position far from a building model. By adjusting a height of the fence and the distance from the model, an abrupt gust can be produced, which is very similar to the gust in a natural wind. The flow around the building and wind loads are influenced significantly by the characteristics of the approaching gust, so peak wind load do not correspond with the approaching gust speed.The response of a building induced by the gust are influenced by the gust shape and the duration of the gust. The rectangular gust induces a large over shoot response and the maximum displacement is about twice of the static displacement. When the duration of the gust is as same as the natural frequency of the building, the resonance effect are observed and the effect increases with number of successive gusts. When the gust passes away a building, the response shows a free vibration behavior. The amplitude of the free vibration is very much effected by a shape and a duration of the gust. When the gust duration equals the natural period of a building, the amplitude tends to null in a sinusoidal gust.

在台风中，建筑物和房屋通常会因突然的阵风而破坏。风速突然增加到平均风速的两倍或三倍，然后在这种阵风中逐渐减小。但是，在实践守则中未描述由这种突然阵风引起的风荷载，在这种实践守则中，假定风在相对较长的时间内吹出静止。在这项研究中，通过风洞测试和建筑物在阵风期间的建筑物的反应进行了研究，通过时间序列的数值分析研究，主要从以下两个角度来研究建筑物的响应，1）在风洞中进行突然的阵风，以模拟风洞中的阵风，2）以澄清构建阵地的响应，以使阵阵响应，以使阵阵构建，3），3）通过模型阵阵负载。为了模拟阵风，我们将围栏设置在远离建筑模型的位置。通过调节围栏的高度和与模型的距离，可以产生突然的阵风，这与自然风中的阵风非常相似。建筑物和风负荷周围的流量受到接近阵风的特征的显着影响，因此峰风载量与接近的阵风速度不符。阵风引起的建筑物的响应受阵风形状和阵风的影响。矩形阵风会引起较大的射击反应，最大位移约为静态位移的两倍。当阵风的持续时间与建筑物的固有频率一样相同时，观察到共振效应，并且效果随连续的阵风数量而增加。当阵风消散建筑物时，响应显示了自由的振动行为。自由振动的幅度非常受阵风的形状和持续时间的影响。当阵风持续时间等于建筑物的自然时期时，振幅趋于鼻涕中的无效。