Combined structural and manufacturing optimization of stiffened composite panels

Abstract

Manufacturing considerations have been incorporated into the design optimization of a blade-stiffened composite panel. For the manufacturing analysis, a one-dimensional resin film infusion model is developed to compute the infiltration time of the resin into a fabric preform of the panel. Results are presented showing the effects of structurally important design variables, such as cross-sectional geometry and material properties, on the manufacturing performance of the panel. In addition, the effects of manufacturing process variables, such as pressure and temperature, on the structural performance are studied. The structural problem is formulated to minimize the panel mass subject to buckling constraints. A simplified buckling analysis model for the panel is used to compute the critical buckling loads. The objective of the manufacturing problem is to minimize the resin infiltration time. Optimum panel designs for the manufacturing and structures problems alone, as well as for the combined problem, are generated using a genetic algorithm. These results indicate a strong connection between the structures and manufacturing design variables and trade-offs between the responses, illustrating that a multidisciplinary approach to the problem is essential to incorporating manufacturing into the preliminary design stage.