Physical Testing and Finite Element Analysis of Icebreaking Ship Structures in the Post Yield Region

摘要

The Canadian Equivalent Standards for the Construction of Arctic Class Ships provide a methodology to determine design loads and scantlings for the hull plating and framing members of icebreakers and cargo ships operating in Arctic waters. The design equations explicitly recognize the post yield capacity of the hull structure (plastification of framing and membrane behavior of the plating) under extreme load conditions. This paper summarizes the analytical and experimental work conducted to assess the post yield stability behaviour of typical icebreaker hull panels particularly in regard to the behaviour of the main frames. Two large scale panels, measuring 5000 mm by 2600 mm in plan, representative of a section of the midbody hull structure along the icebelt that extends between the main deck and the bottom structure and between transverse bulkheads of a Canadian Arctic Class 3 (CAC3) vessel, have been tested. The behaviour, load deformation characteristics and progression of failure from plastic hinge formation to plastification and tripping of the framing system, to rupture of the plating is described. A comparison has been made between the behaviour of the panels as predicted by a non-linear finite element analysis and the physical test results to determine the effectiveness of the finite element method in modelling post yield behaviour.