Lightweight design of cylindrical stiffened shells in launch vehicles by a dual-elite population sequential approximation optimization approach

Abstract

A 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.

KEYWORDS:

• Cylindrical stiffened shells
• postbuckling
• sequential approximation optimization
• dual-elite population
• adaptive parallel infilling strategy

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The research presented in this article was supported by the National Natural Science Foundation of China [11902348], the Research Project of National University of Defense Technology [ZK19-11] and the National Key R&D Program of China [2017YFB0306200].