Review of the uncertainties in load and strength modelling in ship collisions

Abstract

Analysis of the dynamic response of ships in collisions requires a realistic idealization of environmental and operational conditions by models suitably idealizing external and internal mechanics. This paper reviews recent research findings of relevance to ship dynamics and structural crashworthiness. The first case focuses on multiphysics dynamic numerical simulations where external dynamics couple an explicit 6-DoF structural dynamic finite element scheme with a hydrodynamic method idealizing the influence of evasiveness in way of ship – ship collision. These simulations reveal that suitable fluid structure interaction modelling may be critical because of the influence of hydrodynamic restoring forces. The second example demonstrates results from quasi-static experimental work on single-sided stiffened and double-skinned steel panels. Results reveal the importance of uncertainties associated with the loading, material and structural gradients of the panels. When physical variations occur at the same location in the panel, dynamics prevail and lead to drastic changes in the load-carrying mechanism and energy dissipation. From an overall perspective it is demonstrated that the multiphysics fidelity of crashworthiness models and quantification of the uncertainties in way of multifield boundaries may influence the results. It is therefore concluded that spatial and temporal discretization may influence dynamic response.