【作者】 江棹荣；

【导师】 倪振华；

【作者基本信息】 汕头大学 ， 减灾防灾与防护工程， 2006， 硕士

【摘要】 本征正交分解(POD)是以能量表述的随机场的最优分解，是一种数据压缩和特征萃取的工具。采用Mercer定理、瑞利商概念及其极值性质推导了POD原理。对双坡屋盖和圆拱顶屋盖用同步多点压力扫描系统进行了风洞试验，根据POD技术采用前若干阶本征模态重建了屋盖风压场。采纳两种方案预测未布置测压孔位置的风压时间序列。第一种方案中利用插值技术获得没有测压孔位置的本征模态。第二种方案对参考屋盖和需预测的新屋盖分别进行试验，结合由参考屋盖试验萃取的本征模态和由新屋盖试验的风压数据计算的主坐标，预测出新屋盖未知区域的风压时间序列。对预测风压包括均值、均方根值、极值在内的统计特性，时程曲线以及功率谱与实测风压作了比较。并且分别通过使用荷载相关法(LRC)计算双坡屋盖的背景响应以及使用完全二次型组合法(COC)计算圆拱顶屋盖风致响应对所提预测方法的有效性进行了检查。最后通过计算前数阶主坐标的功率谱结合其对应的本征模态近似求解圆拱顶屋盖脉动风压功率谱，从而计算屋盖的风致响应，以提高COC响应计算的效率。更多还原

【Abstract】 The Proper Orthogonal Decomposition (POD) is an optimal decomposition of random fields in terms of an energy representation. The principle of POD is deduced by the Mercer theorem and the concept of Rayleigh quotient and its extreme property. A study of reconstruction and prediction of wind pressure field on roof using the proper orthogonal decomposition (POD) is presented. The wind tunnel tests of a pitched roof and dome-like roof are conducted by using the synchronous multi-pressure scanning system. Based on POD technique, the pressure field of the roof has been reconstructed by the first several proper modes. The pressure time series on locations of the roof where the pressure taps are not distributed have been predicted by two schemes. The interpolation technique is adopted to obtain the proper modes on locations without taps in the first scheme. In the second scheme two measurements are involved for a reference roof and a new roof which is to be predicted, respectively. The proper modes extracted from the measurement of the reference roof and the principal coordinates computed via pressure data from the measurement of the new roof are combined to obtain the pressure time series on the unknown regions of new roof. The statistics, such as the mean value, root mean square value, peak value, time-history curves and auto-spectra of the predicted pressures have been compared with those of the measured pressures. At last, the wind-induced responses of roof are calculated and compared by using the predicted pressure data and the measured pressure data. The effectiveness of the proposed prediction approach is examined by analyses of the wind-induced responses of the roof, obtained from the calculation with Load-response-correlation(LRC) method for pitched roof and Complete-Quadratic-Combination (CQC) method for dome-like roof.更多还原