粘性阻尼系统频响函数计算方法

基于复模态理论和幂级数展开原理，导出了一种求解粘性阻尼系统频响函数的模态加速方法。与常规的模态展开法相比，该方法可大大减少模态截断误差。根据外激励频率所处于的系统频段，该方法可对系统的中-高、低-高阶模态实施截断和加速。通过对一数值实例计算表明，上面提出的方法很有效，通常只需计入幂级数前少数几项即可使频响函数达到很高的精度。

A METHOD FOR COMPUTING FREQUENCY RESPONSE FUNCTIONS OF VISCOUS DAMPED SYSTEMS

Based on the complex modal theory and power series expansion theorem, a modal acceleration method for calculating the frequency response fonction (Far) of viscous damped systems was derived. Compared to the typical modal superposition method, the proposed algorithm can reduce the modal trUncated errors significantly when modal mincation is adopted. The middle-high, low-high modal of the system can be truncated and accelerated according to the excited frequencies by using this method. Numerical example demonstrates that the present method is very efficient and the Far has very high accuracy when only several items of the power series are considered.