【作者】 孙斌；

【导师】 罗尧治；

【作者基本信息】 浙江大学 ， 结构工程， 2013， 博士

【摘要】 现场实测、实验室模拟及理论分析是结构风工程的三种主要研究方法,其中实验室模拟及理论分析必须以现场实测为标准。由于实施难度较大,世界范围内的实测试验数量较少。本文对世界上已有的实测试验进行了列表总结和综述,阐明了实测设备是制约实测试验开展的最重要因素。首先,本文在实测“数据采集三原则”基础上研发了适用于土木工程领域的无线风速风压传感系统。本文提出风致内压理论可以解决风压传感器标定所面临的困难,并制作了一个立方体模型,利用模型内压成功标定了无线风压传感系统。其次,对风压实测试验所必须面对的参考压力问题进行了分析,分析结果显示,参考静压问题的本质是建筑物周围的风致静压场。本文在风洞中对一个立方体模型的周围静压场进行了探测,针对目前无法精确测量静压的情况,提出了一种无量纲化方法,给出了静压场的分布规律,运用幅值域及频域方法详细分析了建筑物周围各区域的流场特性,之后给出了静压场主要方向的分布函数型式,并推断了静压场的静力及动力边界。通过CFD数值风洞方法深入研究静压场分布规律,发现建筑物周围近距离范围内有两条狭长地带能用于快速测量参考静压,称之为“静压走廊”,通过一定方法可确定其位置及走向。其后,对一典型三心圆柱面网壳进行了风洞试验和CFD数值模拟,结果显示数值模拟能较准确反映实际情况,在此基础上,对两个柱面网壳并列布置的风致干扰效应进行了研究,该结果与静压场的研究结果相符。再次,本文利用所研发的无线风速风压传感系统对浙江大学体育馆屋盖进行了风效应实测。试验过程显示,相比有线设备,无线设备能大大降低设备安装难度及减少试验资金耗费,无线设备的便利性极其突出。实测过程中经历了强台风“海葵”,在其经过杭州前后的近4个小时进行了风效应实测。以实测风速数据对台风“海葵”的风特性进行了分析总结,风洞可利用此风特性模拟强台风。以实测风压数据对浙江大学体育馆的屋盖风压特性进行了研究,发现浙江大学体育馆上的所有风压测点都体现出了强非高斯分布特征,这意味着使用峰值因子法预测大跨度空间结构峰值风压需要特别谨慎,文中给出了峰值因子的推荐取值,并指出了按照现行风洞试验方法所设计的大跨度空间结构屋盖上可能会比较偏危险的区域。实测脉动风速及脉动风压功率谱密度两两不相同,这说明大跨度空间结构屋盖的风压脉动不完全取决于风速脉动,故本文通过风速风压实测确定准定常假定在大跨度空间结构上不适用。本文通过设备研发、设备标定、实测方法研究,再到利用此设备进行真实建筑的实测试验,开启了利用无线传感设备进行结构风工程实测的崭新途径,本文的思路及设备可对未来结构风工程实测试验提供参考。更多还原

【Abstract】 The three main research methods of structural wind engineering are field measurement, lab simulation and theoretical analysis. Lab simulation and theoretical analysis must be validated by field measurement. But very limited number of field measurements has been obtained around the world because of the difficulty. The field measurements around the world were listed and reviewed, and the most difficult thing that restricts the development of field testing is the instrumentation.Hence wireless sensor devices were developed based on the three principles of field measurement data acquisition firstly in this paper.The wireless sensor devices must be calibrated before actual use, so the wind-induced internal pressure theory was introduced to the test. Then a cubic model was made and the devices were calibrated by measuring the internal pressure of the cube in wind tunnel.The choices of the reference pressure of pressure sensor were analyzed, and it was noted that the nature of problem of the reference static pressure is the static pressure field around a building. Thus wind tunnel tests in smooth and turbulent flow, with and without a building were carried out to detect static pressure fields. A dimensionless method was proposed to solve the problem that static pressure can hardly be measured exactly, therefore the distributions of static pressure fields were investigated, dynamic characteristics of different flow areas around a building were analyzed in details by amplitude domain and frequency domain analysis methods, distribution formulas of main directions were given, and then the static and dynamic boundaries were concluded. More CFD investigations of static pressure fields revealed there are two narrow strips of regions near a building which can be used to quickly measure reference static pressure and so be named "static pressure corridor", and the method to find their positions and directions was proposed.CFD simulation was performed to compute a typical three-center cylindrical latticed shell, and the results from the computation and the wind tunnel test was compared, which indicated that the numerical result was closed to the practical mean wind pressure distribution. Based on this, two latticed shells were arranged in parallel and the wind-induced interference effect was investigated, and the result is the same with the static pressure field study.After that, full-scale field measurement of wind effect on the roof of Zhejiang University gym was carried out with self-designed wireless sensor devices. The test indicated that device installation will be much easier and the cost will be reduced with wireless devices, the convenience of wireless devices is impressive.Severe typhoon "Haikui" passed through Hangzhou city in the period of the field measurement, and near4hours data were collected then. Wind characteristics of "Haikui" were generalized from the measured wind velocity data, which can be referenced to the simulation of typhoon in wind tunnel test. Wind pressure characteristics on the roof of Zhejiang University gym was revealed from the measured wind pressure data, non-Gaussian characteristics is noted at all pressure taps, so it must be careful to employ the peak factor approach on long-span spatial structures. The value of the peak factor was recommended in this paper. And the dangerous areas were pointed out if the nowaday wind tunnel analysis method was employed. The power spectrum density figures of wind speed and wind pressure are all different, which implies that fluctuating wind pressure on long-span roof does not depend on fluctuating wind velocity, therefore the quasi-steady approach is not applicable to long-span spatial structure.Device development, device calibration, investigation of field test method, then field measurement on a real building were introduced in detail in this paper, a way out of full-scale field measurement with wireless sensor devices was present, the ideas and the devices here can be referenced to the future field measurement of structural wind engineering.更多还原