Optimization Design of Laminated Spherical Shells with Hygro-Thermal Stability

Composite structures featuring asymmetric stacking sequences possess the potential to significantly enhance mechanical properties, owing to a broader design domain for fiber angles compared to symmetric stacking sequences. However, the implementation of an asymmetric stacking sequence renders composite structures more prone to curing warping deformation. To achieve an optimal asymmetric design for a laminated spherical shell, this paper derives the analytical expression of the condition for its hygro-thermal stability, which reveals that the problem of curing warping deformation of an asymmetric laminated spherical shell can be solved by reasonable fiber angle design. Furthermore, taking the ground hemispherical radome shell as an application background, an asymmetric optimization model of a laminated spherical shell is proposed with the precondition of the structure’s electromagnetic wave transmittance. Under the constraint of hygro-thermal stability, the wind resistance performance of the hemispherical radome shell is improved by designing asymmetric fiber angles, and the maximum increase reaches 7.06%. Numerical verification results show that if the stacking sequence meets the condition for hygro-thermal stability, the spherical shell will not undergo hygro-thermal shearing or warping deformation, no matter what kind of fiber-reinforced material it is. Finally, the robustness analysis of optimal stacking sequences is completed to ensure the results are practical when considering random deviation of fiber angles during fabrication.