Lightweight design of cylindrical stiffened shells in launch vehicles by a dual-elite population sequential approximation optimization approach
Zhixiang Wang, Yongjun Lei, Zeping Wu, Xing OuYang, Dapeng Zhang, Guanri Liu · Engineering Optimization · 2020
Zhixiang Wanga, Yongjun Leia*, Zeping Wua, Xing OuYangb, Dapeng Zhanga & Guanri Liuba College of Aerospace Science and Engineering, National University of Defense Technology, Changsha, People’s Republic of Chinab Beijing Institute of Astronautical Systems Engineering, Beijing, People’s Republic of ChinaCONTACT Yongjun Lei [email protected] nonlinear displacement-controlled loading dynamic method is employed to investigate the deformed shape evolution of stiffened shells from prebuckling to postbuckling field until collapse. Because of the time-consuming postbuckling analysis, the dual-elite population sequential approximation optimization (SAO) approach is proposed. A novel determination method of Gaussian kernel widths based on moment estimates is proposed to enhance the augmented radial basis function surrogate model. A novel adaptive parallel infilling strategy is then developed to balance the capabilities of local and global optimization. A dual-elite population strategy is further developed to exploit the information from already acquired sampling points. Finally, the framework of the proposed SAO approach, which is implemented in a distributed parallel way on high-performance clusters to further diminish computation costs, is presented. The efficiency of the algorithm is validated by the postbuckling lightweight optimization of a cylindrical stiffened shell, resulting in a reduction of 12.3% of the initial weight.