Integrating Crashworthiness into the Concept Design Phase of Tanker Structural Design Through Surrogate-Based Optimization

A key limitation of conventional early-stage oil tanker structural design is that the accidental limit state performance is rarely included as an explicit design objective, even though major topology and arrangement decisions are taken before detailed nonlinear analyses become feasible. This paper proposes a crashworthiness-driven structural design methodology for the concept design phase (CDP), in which crashworthiness is introduced as an explicit safety-related performance measure through surrogate modeling and used within a multi-objective optimization framework. Crashworthiness is represented by the internal energy absorption of a double-hull side structure under collision, which is obtained from a limited set of high-fidelity nonlinear simulations and approximated by response surface surrogate models to enable computationally efficient design-space exploration. The optimization framework considers structural weight and crashworthiness while enforcing rule-based adequacy constraints consistent with current classification practice, and it can be extended to additional safety-related measures. Application to an Aframax tanker case study demonstrates that Pareto-optimal solutions can be generated that improve the collision energy dissipation capability without disproportionate increases in structural weight at a stage where topology changes are still practical. The results confirm that crashworthiness-oriented criteria can be embedded within CDP design workflows in a manner compatible with established industrial practice.