Longitudinal strength analysis of ship hulls of composite materials under sagging moments

An approach to estimate the longitudinal strength of ship hulls in composite materials is presented in the paper. Typical ship configurations have as dominant failure mode the failure of the deck under compression associated with sagging moments. Ship hulls are modeled as assemblies of stiffened composite panels. Buckling, material failure and ultimate collapse of the stiffened panels are predicted by nonlinear finite element analysis, which is based on a degenerated three-dimensional laminated composite shell element with updated Lagrangian formulation and first-order shear deformable kinematics. According to buckling, material failure and ultimate collapse of stiffened panels, the corresponding longitudinal strengths of ship hull are derived from a simplified method. A ship hull under sagging is analysed as an example application.