POD在大跨屋盖风致响应计算中的应用

Application of POD to calculation of wind-induced response of large roofs

根据风洞试验同步多点压力扫描技术和本征正交分解方法重构作用于圆拱顶屋盖的脉动风力。对重构的脉动风荷载的时间历程曲线及其统计性质与实测风荷载进行比较。计算部分测压点上重构的风荷载的自功率谱、互功率谱及相干函数,并用实测荷载的功率谱作了检查。提出一种采用缩阶技术用完全二次型组合法计算大跨屋盖的风致响应的方法,这种方法利用少量本征模态计算缩阶的主坐标功率谱而得到脉动风荷载功率谱。为检验方法的效率,给出采用不同数目主坐标的圆拱顶屋盖部分节点竖向均方根位移的计算时间和计算误差,以及采用不同数目主坐标的缩阶技术得到的全部节点的竖向均方根位移响应的误差分布。

The fluctuating wind loads on a dome-like roof are reconstructed based on the synchronous multi-pressure scanning technique of wind tunnel tests and the proper orthogonal decomposition （POD） method. The time-history curve and the statistics of the reconstructed fluctuating wind loads are compared with those of the measured wind loads. The auto-spectra, cross-spectra and correlation of the reconstructed loads for some taps are computed and examined in comparison with those obtained from the measured loads. A reduced-order approach to calculating the wind-induced response of large roofs with complete quadratic combination is proposed. In this approach the spectra matrix of fluctuating wind loads is obtained through calculating the reduced spectra matrix of the principal coordinates with a few proper modes. To verify the efficiency of the approach, the computing time and error of the vertical RMS displacements of some nodes of the dome with different numbers of principal coordinates are presented. Moreover, the error distributions of the vertical RMS displacement response of all nodes using the reduced-order technique with different number of principal coordinates are illustrated.