Abstract
Optimized structures with lightweight designs are an essential requirement for aerospace structures. Thin skin composites are utilized in such structures owing to their strength-to-weight benefits. Additionally, varying the fiber angle in the composite structures allows for design with localized stiffness variation. Stiffness variation, especially in bending can also be achieved by varying local thickness. In this study, we attempt to improve the buckling performance of the thin skin structures by combining the fiber angle variation and thickness variation spatially across a panel. The semi-analytical approach was used to calculate the buckling load of the panel was calculated with the objective to increase the buckling load while maintaining the weight of the uni-axially loaded panels. The optimized buckling value was observed to be increased up to 0.5308 N/mm from a quasi-isotropic stack up ([−45/45/45/−45]2s) of constant thickness plies (0.125 mm each), by varying the fiber angles of the laminate stack, with a further increase up to 1.49 N/mm by inducing thickness variation along with the varied fiber angles.
