Tool for initial hull structure dimensioning at ship concept design

During the ship concept design, the hull weight estimates are generally based on top-down methods such as empirical formulas resulting from statistical analysis of data from existing ships and using as variables the main dimensions and some hull form coefficients. These formulas are generally outdated, and do not reflect the actual configuration of the hull structure. In this work, a tool for the initial dimensioning of the hull structure by class rules was developed as an additional module of a ship numeric model for the ship concept design. A non-linear constrained optimization procedure is used to obtain the scantlings of plates and stiffeners that minimize a measure of the structural weight per unit length. The methodology adopted and the data models are presented as well as the results of a case study application.