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.

本文研究了在不同边界条件下承受面内压缩载荷的曲线网格加劲度可变刚度复合圆柱弯曲板的屈曲性能。开发了Python-Abaqus脚本来执行面板的屈曲分析。提出了一种新颖的基于平面网格包裹的方法来简化具有复杂几何形状的这种弯曲面板的建模。这种方法具有许多优点，包括但不限于使用常规壳体元素分别对蒙皮和加劲肋进行建模，以及独立地研究每个组件的网格收敛，从而导致更有效，更健壮的有限元模型适合优化实现。使用提出的方法，进行了各种参数研究，以研究面板曲率以及由纤维和加劲肋产生的刚度变化对屈曲响应的影响。随后，执行优化例程以同时确定用于最大屈曲能力的最佳纤维和加强筋路径。结果表明，通过用曲线形的加强筋代替直的加强筋，可以增强网格加筋的准各向同性蒙皮的屈曲阻力。还表明，面板弯曲度对格栅加劲肋的最佳布局有重要影响。