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 design variables that are important for structural performance, such as crosssectional geometry variables and material properties, on the panel manufacturing effort. 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. The results indicate a strong connection between the structural and manufacturing design variables and tradeoffs between the two responses, and illustrate that a multidisciplinary approach to the problem is essential to incorporate manufacturing into the preliminary design stage.