Robustness optimisation of opening casing wall-strengthened cylindrical pressure hulls based on 6σ

ABSTRACT

This study determines a numerical analysis method for optimising the safety performance of a opening casing wall-strengthened cylindrical pressure hulls. After dimensional reduction of the design variables, the sample points are selected using the optimal Latin hypercube method, and fitted with the response surface model (RSM). After solving the deterministic lightweight optimisation problem, the weight of the hull is significantly reduced but the robustness is poor. Moreover, the robustness is little improved by a lightweight multi-response robustness optimisation on the pressure hull. Furthermore, the weight and ultimate strength are taken as the objective functions in a multi-response multi-objective robustness optimisation model. The optimisation obtains a Pareto solution set, from which four representative schemes are selected for further analysis. The σ levels of the constraints and ultimate strength increased to 8 without markedly changing the weight, indicating significant robustness improvement of the pressure hull.

KEYWORDS:

• Opening casing wall-strengthened
• cylindrical pressure hull
• correlation analysis
• approximate model
• robustness optimisation

Acknowledgement

This research was supported by the College of Shipbuilding Engineering, Harbin Engineering University.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by National Natural Science Foundation of China: [grant number 51709063].