A carbon fiber composite reinforced barrel shell with higher underwater pressure resistance performance

In this paper, the buckling properties of unreinforced and reinforced barrel shells of carbon fiber composite with positive Gaussian curvature under hydrostatic pressure are systematically investigated by combining theoretical, finite element simulation and experimental methods. The derived analytical formulas for buckling considering the effects of structural curvature and ribs are verified by finite element analysis to have a high prediction accuracy within 10%. Parametric analyses and failure mechanism diagrams of barrel shells and reinforced barrel shells are carried out to investigate the effects of factors such as length-to-diameter ratio, thickness-to-diameter ratio, layup angle, deformation, number and size of ribs on the critical buckling load of the shells. One cylindrical shell, two barrel shells and two reinforced barrel shells are designed, fabricated and measured under equal-volume conditions, prepared by integrated fiber winding molding using a split-flap mold. The test results show that the critical buckling load of barrel shells is enhanced by 32.03% on average compared with that of the equal-volume cylindrical shell, while the reinforced structure significantly improves the stability of barrel shells, with an average increase of 117.08% in the load carrying capacity. The results can provide relevant references for the structural design and preparation of composite pressure-resistant shells.