| A hybrid ship structure could potentially combine the benefits of both steel and composites to obtain possible superior characteristics. In this dissertation, a hybrid ship hull made of a steel truss and composite sandwich skins was investigated. The steel truss was designed to carry the bending loads, whereas the composite skins were designed to carry shear and water pressure loads. A 142 meter ship hull, similar to a destroyer in terms of size, weight and speed, was designed, finite element analyzed and optimized. A 6 meter model was subsequently developed, finite element analyzed, manufactured and tested under sagging loads. The model was loaded to 36% above the design load, at which point there was substantial yielding and residual deformation of the steel truss. However, there was no indication of failure in any of the composite sandwich panels, nor in the bonds between the panels and the steel truss. Joints in hybrid structures were also investigated in the dissertation, including joints between a steel hull and a composite superstructure, and between a stainless steel Advanced Double Hull and a composite bow/stern. Joints were designed and specimens were manufactured and tested mechanically and environmentally. |
