To meet the lightweight design requirements of ship composite structures, this paper proposes a multi-objective optimization method for composite laminate layup. The method integrates the NSGA-II algorithm with the micromechanical Voigt-Reuss model and classical lamination theory. Furthermore, a novel tiered constraint strategy, tailored to the loading characteristics of ship structures, is introduced for the first time in the industry, successfully achieving the multi-objective (dual-objective) optimization of laminate layups. Taking a 40-layer carbon-fiber laminate as an example, the optimized design achieves a 14.6% increase in stiffness and a 98% satisfaction rate of manufacturing constraints compared to conventional methods. Finite-element verification under clamped boundary conditions shows a 32% reduction in maximum stress and a 12% increase in the first-order natural frequency. The application of this method to a high-speed composite catamaran demonstrates that the optimized hull-girder design leads to a 10% reduction in deflection and a 15.6% decrease in the fiber stress utilization factor in longitudinal strength calculations. This study provides a valuable reference for advancing ply-optimization design techniques for ship composite structures.

Since the successful application of the IMO's Goal-Based Ship Construction Standard (GBS) in the hull structure rules for oil tankers and bulk carriers by the International Association of Classification Societies (IACS), the GBS has gradually been promoted to various maritime fields and the development of specifications for all types of seagoing vessels. The state-of-the-art of the GBS in the research of rules for seagoing vessels at home and abroad is summarized to deeply analyze the technical characteristics of the hull structure rules based on the GBS. A framework is accordingly proposed for adoption of the GBS in the hull structure rule system of the China Classification Society (CCS).