Sensitivity analysis of risk-based conceptual ship design
The presented work performs a sensitivity analysis of conceptual ship design of a multipurpose vessel employing a risk-based framework for design. The risk-based framework includes conceptual design to define initial dimensions and characteristics of the ship based on the optimization of the required freight rate, stochastic load modelling, progressive collapse accounting for corrosion degradation during the service life, reliability and cost benefit analysis and finally risk management and sensitivity analysis. The impact of three type design modification factors related to ship design modification: length, block coefficient and service speed; structural design modification associated with the re-scantlings of the midship section leading to different stiffness of principal structural components and cost modification factors associated with the labour, steel, equipment and outfit, machinery costs, profit and overheads are analysed here. Several conclusions with respect to the most significant modification factors are derived. It is analysed the effect that ship design variables (Lpp and Cb) and building cost related variables (cost of a ton of steel, number of crew and more) have over the final estimation of the costs and is taken consideration of the sensitivity of these.