Analysis and Design Optimization of Grid Stiffened Composite Cylinders

Skin-stiffener structures are extensively used in the aerospace field due to their structural efficiency in terms of stiffness/weight and strength/weight ratios. The application of such panels is primarily within fuselages and wing boxes, where the weight saving potential of composite materials compared with aluminum alloys is well known. However, design of composite panels involves the optimization of a large number of variables such as ply thickness and plate widths. Further complication arises when the expert knowledge required for laminate design is considered and when the panel is constrained by buckling under axial compression. In this study, the behavior of Grid Stiffened Composite Cylinder is examined under the axial compressive load. Compressive load causes buckling and develop stresses in the structure. For the buckling analysis two approaches are used.(1)Analytical (2)FEM. An analytical smeared stiffener theory is used to determine buckling load and then FEM results were compared to gain the confidence on the developed models. The validated FEM model and analytical smeared stiffener theory is used to conduct parametric analysis.