适用瞬态响应计算的火箭结构动力学模型修正方法

大型火箭结构十分复杂，其连接型式多，存在多分支结构。分析火箭结构中存在弱刚度的内-外翻边连接、螺栓点连接等典型连接型式，基于元素型法，以这些部位刚度为修正参数，开展动力学模型修正方法研究。结果表明，采用的方法能保证修正后模型的物理意义和真实性，能够适用于瞬态外激励作用下的结构响应计算，特别是内力响应计算。修正后模型的各阶模态结果和试验吻合较好，且与实际试验中瞬态响应的实测结果相比，计算具有较高精度，能够满足工程需求。

An Updating Method for Structural Dynamic Model Applicable for Transient Rocket Response Computation

The structure of large-scale rocket is very complicated due to its different types of connections and multi-branch structures. In this paper, some typical connections, such as weak stiffness connection, flanging connection and bolt point connection, were analyzed. Based on the element method, the stiffness of these connections was selected as the updating parameters and a dynamic model updating method was presented. The results showed that the physical meanings and truthfulness of the model after the updating are reserved, and the presented method is suitable for the structural response analysis, especially for the internal force response calculation under transient excitation. The modal results of the updated model can check well with the experimental results. Compared with the measured transient response in real flight, the computation results were found to have quite high accuracy, which shows that the method is applicable for engineering design.