The dynamic characteristics of system, namely the damping ratio, natural frequency, and mode shape are extracted from the frequency response function (FRF). Obtaining dynamic characteristics through FRF on large rotor system is impractical owing to safety and cost. Therefore, the dimensional scale method to predict FRF on a large rotor system is proposed. The method begins by deriving the scaling factor of FRF followed by its validation using finite element (FE) and transfer function modeling. In this case, the transfer function completes the FE modeling to describe the FRF system and compensates the lack in FE modeling in dealing with complex support and shape. Assuming the damping ratio is constant, the characteristic of dimensional analysis through FRF is obtained and the complexity of the proposed method is also discussed.

从频率响应函数（FRF）中提取系统的动态特性，即阻尼比，固有频率和振型。由于安全和成本的原因，在大型转子系统上通过FRF获得动态特性是不切实际的。因此，提出了一种用于大型转子系统的FRF预测的尺寸尺度方法。该方法首先得出FRF的比例因子，然后使用有限元（FE）和传递函数建模对其进行验证。在这种情况下，传递函数完成了描述FRF系统的有限元建模，并弥补了有限元模型在处理复杂支撑和形状方面的不足。假设阻尼比是恒定的，则通过FRF获得了尺寸分析的特征，并讨论了该方法的复杂性。