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为解决高保真失谐叶盘计算量大的问题,提出了一种新的减缩建模及动力响应预测方法。该方法对叶盘单扇区有限元模型进行圆周对称分析,获取谐调叶盘在局部坐标系下的基本模态特性。同时,运用主节点的概念,仅对少量节点进行模态分析,在大大降低矩阵维度的同时获取准确的失谐模态特性。在动力响应预测分析时,利用失谐固有频率点处响应的基本特性,仅选取危险频段内、危险叶片上的危险节点进行响应分析计算,既极大地提高了运算效率,又能够准确地获取叶盘最大受迫响应幅值。实例分析结果表明:相较于传统的有限元方法,该方法中模态分析的求逆过程矩阵维度从150万下降到384,计算所得的前50阶固有频率的精度保持在0.005%以内,最大响应计算过程运算量下降超过99%时,仅存在-0.35%的误差。
In order to solve the large computational burden of high-fidelity detuning disc, a new reduction modeling and dynamic response prediction method is proposed. This method performs circular symmetry analysis on the single leaf sector finite element model and obtains the basic modal characteristics of the harmonic leaf disk in the local coordinate system. At the same time, using the concept of master node, modal analysis of only a few nodes can obtain accurate detuning modal properties while greatly reducing the matrix dimension. In the dynamic response prediction analysis, only the dangerous nodes in the dangerous frequency band are selected for the response analysis and calculation by using the basic characteristics of response at the detuning natural frequency point, which not only greatly improves the operation efficiency but also accurately obtains the leaf Disk maximum forced response amplitude. The results of the example analysis show that compared with the traditional finite element method, the matrix dimension of the inverse process of modal analysis in this method decreases from 1.5 million to 384, and the accuracy of the calculated natural frequency of the first 50 orders remains within 0.005% Response Calculation Process When the amount of operation drops by more than 99%, there is only -0.35% error.