Optimal Design of Advanced Grid Stiffened Composite Cylindrical Shell

Abstract

Advanced Grid Stiffened (AGS) composite cylindrical shells are widely used in aerospace industry. Firstly, the buckling loads for various types of grid structures of AGS composite cylindrical shells were analyzed, and Iso-grid AGS type was selected as a study object which has generally good performance for all conditions. In this study, whole structure weight of the Iso-grid cylindrical shell was kept constant, in which condition the design variables such as grid angle, number of grids, grid height and grid thickness were controlled. Secondly, these variables were optimized by Optimal Latin Hypercube of the DOE method, using Isight. There has two objective functions, one is weight of the structure (for target value), and the other is buckling load (for maximum value). This study was performed through finite element analysis using Abaqus and the accuracy of the analysis was verified by previous studies. Finally, based on the result of numerical simulation, a variable of the skin thickness was added and analyzed whole scale of the AGS composite cylinder. The result shows the influence of each variable on the structure, which can be applied to the optimization of grid structure design, and is also very helpful for reducing the computational cost and obtaining optimization values more accurately.