Strength and stability of spherical pressure hulls with different viewport structures

This paper focuses on three viewport structures of a deep-sea spherical pressure hull. By employing the rule design method, the plane disk, conical frustum, and spherical sector viewport structures were designed, and its basic dimensions were determined. The strength and stability of pressure hulls with three different viewports were examined by employing theoretical and numerical methods under the condition that Di and t were consistent. To satisfy the strength requirement, the effects of the structural parameters of the conical frustum viewport on the stress and deformation of the contact surface were studied, and the reasons for failure, in addition to the design criterion, of acrylic plastic viewports were investigated. Additionally, equally proportioned models of pressure hulls with three different viewports were manufactured and tested. The geometrical and buckling properties of these spherical hull specimens were demonstrated via a series of tests. The results of theoretical, numerical, and experimental investigations were compared by constructing tables and figures. •The spherical pressure hulls with three different viewports were designed.•The effects of different viewport structures on the strength and stability of the spherical pressure hull were investigated.•The geometry and buckling of three equal-proportion models according to the design result were tested.