利用机体试验模态分析结果建立了用于机体结构动态特性分析的有限元模型，分析了机体振动模态及结构刚度的分布变化规律，将矩阵摄动理论及灵敏度分析方法应用于机体动态特性的修改之中，确定影响机体各阶动态特性的结构参数及其位置，优化结构动态特性，使得针对某一频率的减振降噪成为可能。文中对机体结构动态设计的几个主要步骤进行了探讨。 The finite element model used to analyze the dynamic characteristics of the body structure is established by using the experimental results of the body test. The variation regularity of the vibration modes and structural stiffness of the body is analyzed. The matrix perturbation theory and the sensitivity analysis method are applied to the dynamic characteristics of the body During the modification, the structural parameters and their positions that affect the dynamic characteristics of the various stages of the body are determined, and the dynamic characteristics of the structure are optimized so that the vibration and noise reduction for a certain frequency is possible. In this paper, several main steps of dynamic design of body structure are discussed.