Reliability-based optimization of ship structure based on interest subdomain dynamic surrogate model

1 COSCO Shipping Specialized Carriers Co., Ltd., Guangzhou 510623, China

2 State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai 200240, China 3 Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai 200240, China Abstract: ［Objectives］Aiming at the difficulty of ensuring the fitting accuracy and optimization efficiency of surrogate models due to the high nonlinearity in ship structure reliability-based optimization design, a reliability-based ship structure optimization method based on the interest subdomain dynamic surrogate model is proposed.［Methods］This method puts forward the concept of the interest subdomain based on the sequential optimization and reliability assessment (SORA) method, determines the range of interest subdomains and formulates adaptive spatial reduction rules based on information entropy function H, then proposes an adaptive spatial reduction sequential sampling strategy based on interest subdomains, thereby constructing a dynamic Kriging surrogate model that highly fits the subdomain of interest locally with as few sample points as possible, and embedding the surrogate model and multi-island genetic algorithm (MIGA) in the SORA method to undertake reliability-based optimization.This study proposes a probability constraint feasibility checking method to reduce unnecessary reliability assessment processes. A mathematical example is given to verify the reliability-based optimization method.［Results］The relative error between the optimal solution and theoretical solution is 0.066 8%, and the number of function calls is 40.6% less than those of the optimal method in the references, which proves the accuracy and efficiency of this method.［Conclusions ］ When the proposed method is applied to the reliability optimization design of a cabin structure, the total cabin mass is reduced by 0.511% compared with the references, and 94 fewer finite element calculations are required, proving the efficiency and applicability of this method.

Key words: ship structure； reliability-based optimization； SORA method； interest subdomain；dynamic surrogate model

收稿日期: 2020–07–26 修回日期: 2020–09–16 网络首发时间: 2021–07–05 13:05

作者简介: 罗文俊，男，1994 年生，硕士生。研究方向：船舶结构可靠性优化研究。E-mail：luo.wenjun@coscoshipping.com王德禹，男，1961年生，博士，教授，博士生导师。研究方向：船舶与海洋工程结构力学，结构优化设计与可靠性分析，结构极限强度与试验技术研究。E-mail：dywang@sjtu.edu.cn

*通信作者:王德禹