Abstract: The strength of the connection structure has always been a key issue in the structural design of a launch vehicle. In this paper, the finite element analysis method is used for the strength of typical connection structures of a new launch vehicle. The research scope includes the inter-stage connection structure and the bundle connection structure. Aiming at establishing the strength of these two connection structures under flight conditions, we built a refined finite element model, simulated the bolt tensile test and obtained a calculation criteria, and carried out finite element analysis of the connection structures under flight conditions. As a result, we not only established the analysis and evaluation method of the connection structures based on the refined finite element modeling analysis, but also provided a fast numerical simulation design method for the development of the launch vehicle’s connection structures, which greatly improved the design efficiency and reduced the design risk.

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