Testing and analysis of a 6-m steel truss/composite skin hybrid ship hull model

A hybrid ship hull made of a steel truss and composite sandwich skins was investigated experimentally and numerically. A 6-m model was tested under hogging loads, after having previous been subjected to sagging loads. All loads were introduced as shear through brackets welded to bulkheads. The model was loaded to the design load, at which point there was plastic yielding of the steel truss. However, there was no indication of failure in any of the composite sandwich panels, nor in the adhesive bonds between the panels and the steel truss. The steel truss started to yield at lower strains than expected, a fact which was elucidated by manufacturing and testing subcomponents of the steel truss. Nonlinear elastic-plastic finite element analyses were performed on the complete hull. Results from the numerical analyses were compared with data from both sagging and hogging tests and good correlation was found.