Dynamic Collapse of the Hull Girder in a Container Ship in Waves

Abstract

The interest on the influence of dynamic effects on the hull girder loading has increased in the last years. Research shows a high influence of whipping and springing on the fatigue loading. The influence on the extreme loading and the resulting dynamic collapse is currently not estimated. The ultimate capacity is described by a static estimation neglecting dynamic influences. Recent research has proven a high contribution of whipping and springing on the hull girder strains. In this thesis methods are discussed and a first approach on the estimation of the dynamic collapse is performed. A broad literature review is performed to base the work on solid research. Calculations are performed in the non-linear finite element program ANSYS. The influence of several parameters on the buckling behaviour is checked and the method validated against analytical results. A model of the midship section is build and is verified by a check of the ultimate capacity against an incremental method. The effect of inertia and rigid body motion of the ship is accounted for. A measured strain series is applied on the hull girder as a quasi- static load set and a full load set including whipping. The results are critical discussed and a plan for future research is provided. The project means to give a first investigation in this topic and shows the pitfalls encountered during the work.