Surrogate-based optimization of stiffened shells including load-carrying capacity and imperfection sensitivity

• Stiffened shell with outward hyperbolic generatrix shape is a robust design choice.
• Inward hyperbolic shape can increase the load-carrying capacity of perfect stiffened shells.
• Optimization including load-carrying capacity and imperfection sensitivity is proposed.

Stiffened shells are very sensitive to initial imperfections, especially for geometrical imperfections. In this study, based on a 3-m-diameter orthogrid stiffened shell, post-buckling and imperfection sensitivity analyses are performed by use of explicit dynamic method. Result indicates that stiffened shell with outward hyperbolic generatrix shape shows a lower imperfection sensitivity as compared to the cylindrical one. Then, a framework of surrogate-based optimization including load-carrying capacity and imperfection sensitivity for stiffened shells is introduced, and the illustrative example demonstrates that the proposed framework has the potential to provide robust optimum design for realistic stiffened shells.