Structural safety assessment under 6-DOF loads and vibration characterization of ship superstructures

This study evaluates the structural integrity of ship superstructures and examines the vibration characteristics of applied materials under operational loading conditions using finite element–based analyses. The structural safety of a composite ship superstructure was first investigated by considering wind loads in combination with six-degree-of-freedom (6-DOF) ship motions. All inverse response function (IRF) values remained below unity, confirming that the structural safety of the superstructure is maintained under combined wind loading and 6-DOF motion conditions. In addition, this study examined the feasibility of replacing conventional metallic superstructures with lightweight composite materials to achieve hull weight reduction and to assess fatigue durability against vibration-induced damage through computational simulation prior to practical application. The results indicate that a hybrid laminate configuration combining carbon fiber and glass fiber is effective in ensuring structural safety. The laminate architecture efficiently distributes applied loads, thereby reducing stresses acting on individual plies as well as on the overall structure. Furthermore, the composite superstructure was shown to withstand wind loading, six-DOF motions and vibratory environments without degradation of structural integrity.