This study takes a typical pressure hull segment of an unmanned underwater vehicle (UUV) as the object and explores its load bearing capacity law based on lightweight design technology.

First, several typical materials are analyzed using the mechanical properties of the pressure hull, load law and optimal critical load design value (stress strength failure and stability failure occur concurrently). The bearing properties of a typical pressure hull with varying depths are then discussed further in terms of the specific engineering requirements.

The failure mode of the shell gradually transitions from stability failure to strength failure as the depth increases, and the optimal critical load design value is proportional to the qualities of the material. Taking bearing efficiency and other factors into consideration, aluminum alloy shells should be selected within the 300 m depth range, titanium alloy and glass fiber composite shells within the 300-600 m depth range, and titanium alloy and carbon fiber composite shells within the 600-1 000 m depth range. In the 1 000-3 000 m depth range, a carbon fiber and boron fiber composite shell is the ideal solution.

The findings of this study can be used to guide the design of pressure hulls for UUVs made of various materials.