某拟建838m高楼多自由度气弹模型风洞试验研究

发布时间：2018-01-09 05:02

本文关键词：某拟建838m高楼多自由度气弹模型风洞试验研究　出处：《湖南大学学报(自然科学版)》2015年01期 　论文类型：期刊论文

【摘要】：为了考察某拟建超高层建筑(总高838m)在设计风速下的风致响应,对该大厦进行了多自由度气弹模型风洞试验.模型自振特性测试表明,该气弹模型各横截面对两个正交的水平主轴对称,每个轴向1阶和2阶频率误差分别在1%和28%以内,1阶阻尼比约为2%,平动振型与实际结构有限元模型计算结果较为一致.分析不同风速和风向角下风致响应发现,该大厦顶部在100年重现期设计风速下最大动态侧移为0.89m,且动态位移本身并未使结构顶部位移超标,而10年,50年和100年重现期下风致加速度响应超过规范阈值幅度分别为16%,23%和29%.另外,该大厦横风向涡振使得临界风速附近横风向风致响应明显偏大,如果假定风荷载谱为白噪声,则横风向1阶气动阻尼比对总响应的贡献达37%.若欲保证该建筑在百年一遇风速下加速度在允许范围内,则须使其结构阻尼比在2.9%以上.
[Abstract]:In order to investigate the wind-induced response of a proposed super-tall building (total height 838m) under the design wind speed, the wind tunnel test of multi-degree of freedom Aeroelastic model is carried out. Each cross section of the model is symmetric to two orthogonal horizontal principal axes, and the first-order damping ratio of each axial direction is about 2% within 1% and 28%, respectively. The calculated results of the translational mode are in good agreement with the actual finite element model. The wind-induced response under different wind speed and wind direction angle is analyzed. The maximum dynamic lateral displacement of the top of the building was 0.89 m under the design wind speed of 100 years, and the dynamic displacement itself did not cause the top displacement of the structure to exceed the standard, but for 10 years. For 50 years and 100 years of recurrence, the wind-induced acceleration response exceeds the standard threshold by 16% and 29%, respectively. The cross-wind vortex vibration of the building makes the cross-wind wind-induced response in the vicinity of critical wind speed obviously larger, if the wind load spectrum is assumed to be white noise. The contribution of the first order aerodynamic damping ratio of the cross wind direction to the total response is 37. To ensure that the acceleration of the building is within the allowable range under the once in a hundred years wind speed, the damping ratio of the structure must be above 2.9%.
【作者单位】：武汉大学土木建筑工程学院;中国电子工程设计院;
【基金】：国家自然科学基金资助项目(51178359)~~
【分类号】：TU973.213
【正文快照】： 风工程研究和工程项目抗风性能分析的风洞试验方式通常有测力天平[1]、刚性模型测压[2]、强迫振动[3]、气动弹性模型[4-7]等.一般来说,对于高度不太高、刚度较大、气弹效应不太明显的高层建筑,通常采用刚性模型测压试验或测力天平试验进行风荷载和风响应分析[8-9],而更为高柔

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