A Load-Carrying Capacity Evaluation Method for the Welded Joints of Rocket Engine Frame

The load-carrying capacities of welded joints need to be paid attention to in the design of the frame, which transfers the thrust generated by the rocket engine to the rocket body. A load-carrying capacity evaluation method of welded joints based on the structural stress method is proposed in this study. Both the ultimate load-carrying capacity and fracture section angle are precisely obtained by the evaluation method. At the same time, a definition of weld-failure stress is given based on the evaluation method and tests. The load-carrying capacity of welded joints in the rocket engine frame is analyzed through the finite element model, including the overall structure and local weld details. The weld-failure stress of welded joints is obtained based on the analysis of three types of welded structures—standard shear specimen, U-shaped fillet welded specimen and pipe-plate fillet welded specimen. The safety factors of the transverse rod and longitudinal bearing rod welded joints of the frame are 8.6 and 13.4, respectively.