风致复杂结构随机振动分析的一种快速算法——谐波激励法

New Rapid Algorithm for Wind-induced Random Vibration of Complex Structures

传统完全二次型组合(CQC)在计算复杂结构随机振动响应时存在计算量巨大的问题,尽管虚拟激励法(PEM)在确保计算精度和CQC方法相同的基础上提高了计算速度,使得复杂结构随机响应的进行分析成真正应用于工程实际,但PEM需要对激励的谱矩阵进行分解,对于处理多点随机激励问题依然比较烦琐。本文从周期图方法计算随机信号功率谱密度出发,提出了一种不需要进行谱矩阵分解即可进行结构随机振动分析的快速算法——谐波激励法,它在理论上和CQC方法同样具有相同精度,计算速度要快于已有的方法,并且由于不需要直接计算激振力的功率谱密度矩阵,因而降低了对内存的需求,算例表明本文方法的有效性。文中对不同方法的适应性也进行了讨论。

The traditional complete quadratic combination (CQC) method has not been widely used for random vibration analysis of complex structures due to the huge computational tasks. The pseudo-excitation method (PEM) has partly solved this problem by means of accurate and efficient computation to apply to the fields of random vibration analysis of complex structures. However, The calculation and decomposition of the excitation PSD matrices, is still time-consuming especially for the vibration analysis of wind-excited large civil engineering structures. An accurate and efficient algorithm, named as harmonic excitation method (HEM), for wind-induced structural random response analysis on the basis of the periodic diagram method. The accuracy and efficiency are examined by comparison with CQC and PEM methods.