考虑螺栓预紧力差异的箭体连接结构动力学响应分析

针对广泛地应用在航空航天箭体结构中的螺栓法兰连接结构的动力学响应特征会显著受到螺栓预紧力大小影响的问题,在螺栓法兰连接结构不同工况下螺栓预紧力出现差异时,研究箭体连接结构的静动力学响应特征。通过对特定的筒壳螺栓法兰连接结构,基于有限元分析和敲击试验来提出一套考虑螺栓预紧力差异的箭体连接结构动力学响应分析方法。并由此研究螺栓松动时的响应特征,基于互补集合经验模态分解算法设计一种新的螺栓松动探测流程,可以量化螺栓发生松动时连接结构的中高频段频响幅值升高的特征,能无损快速地识别松动工况的发生。

Dynamic response analysis of rocket connection structure considering discrepancy of bolt preloads

In order to address the problem that the dynamic response characteristics of the bolted flange connection structure, which is widely used in aerospace rocket structures, are significantly affected by the magnitude of bolt preload, the static and dynamic response characteristics of the rocket connection structure were studied taking into account the discrepancy of bolt preloads under different conditions. A set of methods for analyzing the dynamic response of rocket body connection structures considering the discrepancy of bolt preloads was proposed based on finite element analysis and knock tests for a specific barrel-shell bolted flange connection structure. By investigating the response characteristics of the connection structure with a loose bolt, a new bolt loosening detection procedure based on the complementary ensemble empirical mode decomposition algorithm is proposed which can quantify the characteristics of the increase of the frequency response amplitude in the middle and high frequency bands of the connection structure when the loosening happens, and can quickly identify the occurrence of loose conditions without damage.