Risk-Based Hybrid Light-Weight Ship Structural Design Accounting for Carbon Footprint

The study aims to develop an integrating risk-based formulation and cost-benefit analysis for identifying an optimal ship hull structural design solution where the steel cargo holds aluminium honeycomb sandwich panels to replace inner side shells. The risk of progressive structural failure includes hazards related to environmental pollution due to accidental fuel and oil spills, possible loss of cargo, crew members and ship during operations, and air pollution during shipyard construction and ship voyages. The structural failure incorporates progressive time-dependent structural degradation coupled with ship hull load-carrying capacity in predicting structural integrity during the service life. The ship hull structural failure and associated risk are estimated over the ship's service life as a function of the design solution. The carbon footprint and cost to mitigate the impact for the entire steel and hybrid ship hull structural solution implemented as a sustainable life cycle solution are analysed where the steel ship hull structure is built through primary construction. The cost of structural measures accounts for redesigning the ship structure and implementing aluminium honeycomb composite panels instead of steel plates, reducing steel weight, environmental pollution and cost and increasing the transported cargo and corrosion degradation resistance. It has been found that design solutions AHS1 and AHS2, in which aluminium honeycomb panels replace the inner steel shell plates, enhance the corrosion degradation resistance, and reduce the ship hull's lightweight, reflecting a better beta-reliability index at the time of the first repair with a lower repair cost and more transported cargo. The cost of the ship associated with the design solutions AHS1 and AHS2 is about 11% lower than the steel solutions.