大型站台雨棚风振响应时域和频域法对比分析

Contrast analysis of wind-induced response of large platform canopy by time and frequency domain method

在对某大型火车站站台雨棚屋盖进行了刚性模型测压风洞试验的基础上,采用时域内的直接积分法和频域内的模态叠加法分别计算结构的风致响应,并以时域结果为依据评价频域算法的计算精度。在通过模态叠加法计算风致响应时,分考虑各振型耦合作用的CQC法和不考虑耦合作用的SRSS法分别计算。计算结果表明对于此类大跨屋盖结构振型耦合项的作用不可忽略。最后,还对结构的关键节点进行不同振型阶数的模态叠加法计算,并进一步讨论采用频域法分析时参与振型数量的选取问题。

By using the rigid model wind tunnel test data of a large railway station platform canopy, the wind-induced response of the steel roof was calculated by direct integration method in time-domain and mode superposition method in frequency-domain respectively, and the accuracy of the result got by frequency-domain method was judged by the time- domain result. When using mode superposition method to get the wind-induced response, the CQC method which takes into account the coupling of each mode and the SRSS method which does not think over the influence of coupling were proposed respectively, and the results show that the mode coupling of the long-span roof structure cannot be ignored. The response of the key structure nodes is superposed by using different numbers of modes in order to decide the effective number of modes.