粘弹阻尼结构频响函数计算的高精度模态展开法

本文建立了粘弹阻尼结构频响函数计算的高精度模态展开法。文中表明，用模态展开法计算粘弹阻尼结构的频响函数，只取少数低阶振动模态时，计算误差较大。本文用低阶振动模态和系统矩阵，表达高阶振动模态和蠕变模态对粘弹阻尼结构频响函数的贡献，修正计算误差。该方法可以显著提高计算精度，对计算量的增加不大。文中给出算例，表明了本文提出方法的正确性和有效性。

AN ACCURATE MODAL SUPERPOSITION METHOD FOR CALCULATING FREQUENCY RESPONSE FUNCTION OF VISCOELASTICALLY DAMPED STRUCTURES

An accurate modal superposition method for calculating frequency response function of viscoelastically damped structures is put forward. As shown in this paper, the errors of calculation are considerable, while only a few of low-frequency vibrating modes are used in modal superposition for calculating frequency response function of viscoelastically damped structures. The contribution of high- frequency vibrating modes and creeping modes to frequency response function of viscoelastically damped structures is expressed by the low- frequency vibrating modes and the system matrixes, and the errors of calculation are corrected. In this method, the calculation precision can be improved greatly with limited increase of computational effort. A numerical example is given, which demonstrates the correctness and efficiency of the present method.