LAUSR

Abstract In this paper, the buckling performance of curvilinearly grid-stiffened variable-stiffness composite cylindrically curved panels subjected to in-plane compressive loads under different boundary conditions is addressed. A Python-Abaqus script is developed to perform the buckling analysis of the panels. A novel planar mesh wrapping based approach is proposed to ease modelling of such curved panels with complex geometry. This approach offers numerous advantages including but not limited to separately modelling the skin and stiffeners using conventional shell elements as well as studying the mesh convergence of each component independently leading to more efficient and robust finite element models appropriate for optimization implementation. Using the proposed approach various parametric studies are conducted to investigate the influence of the panel curvature and the stiffness variation created by the fibers and stiffeners on the buckling response. Subsequently, an optimization routine is implemented to simultaneously determine the optimal fiber and stiffener paths for maximum buckling capacity. It is shown that by replacing the straight stiffeners by curvilinear ones the buckling resistance of the grid-stiffened quasi-isotropic skins can be enhanced. It is also shown that the panel curvature has a significant effect on the optimal layout of the grid-stiffeners. Optimization results demonstrate that for shallow curved panels up to 100% improvement in the buckling performance can be achieved by concurrently optimizing the curvilinear fiber trajectories of both the skin and stiffeners compared to their straight fiber and stiffener design counterparts.