Structural design optimization of pressure hull using genetic algorithm and finite element analysis

Purpose The main objective is to develop a new design methodology for pressure hulls, prioritizing steel weight reduction without compromising structural safety. Genetic algorithms (GA) will be employed to optimize the structural weight of the hull of a pressure vessel, considering the Det Norske Veritas (DNV) standard formulation. This includes optimizing both the scantling of the pressure hull and the dimensions of the frames while complying with constraints based on the DNV regulation: nominal, over-immersion and collapse pressures. The proposed solution will be analyzed using finite element analysis (FEA) to verify that the obtained scantlings meet the design requirements. Design/methodology/approach An optimization of the design parameters of the structure of a pressure hull based on GA is proposed. The starting point is individuals randomly generated by combining the different values that each parameter will take. The surviving designs will be required to meet DNV standards and will be ranked according to the structural weight of each design. Prevailing will be those genes that make designs that comply with the standards and are less heavy. Finally, the feasibility of the design proposed by the GA will be tested by FEM. Findings The structural integrity of the design resulting from the application of GA (which complies with DNV regulations) has been evaluated by means of FEM considering different constructive defects. In summary, the proposed methodology combined with GA provides a preliminary design of the pressurized hull in a fast way, ensuring compliance with the structural requirements according to the current regulations. Furthermore, this design is optimized in terms of its own weight. The reduction in structural weight provides a reserve of buoyancy that can be used to increase other weight categories, thus extending the operating time of the pressure vessel. Originality/value This novel approach allows to quickly obtain a preliminary design of a pressure hull structure optimized for minimum weight and ensuring compliance with classification societies. The proposed methodology provides the user with a preliminary design with lower material cost and allows the increase of other weight items.