Research on the deformation mechanism of egg-shaped shells in granular medium bulging.

The design of pressure hull structures plays an essential role in the research and development of underwater operation equipment such as deep-sea submersibles. As a bionic structure, an egg-shaped shell has apparent advantages in the application of an underwater pressure hull. Still, the egg-shaped shell is a positive Gauss surface, so it is difficult to control the manufacturing accuracy and quality. In this paper, the technology of solid particle flexible medium forming and the principle of high-pressure bulging in tubes is proposed to manufacture high-precision egg-shaped shell parts. By optimizing the shape of the punch structure, optimizing the process parameters, improving the stress and strain distribution of the egg-shaped shell, and analyzing the deformation mechanism in the bulging process, we have mastered the deformation and quality control methods of the granular medium flexible bulging of non-equal curvature tubular structures in some aspects. [ABSTRACT FROM AUTHOR]