Optimal Design of Composite Stiffened Cylinder Subject to External Hydrostatic Pressure

This study describes how a microgenetic algorithm can optimize a frame-reinforced composite cylinder subjected to external hydrostatic pressure. The objective of the optimization is to maximize a design allowable load in relation to buckling and static failure loads. The design variables are a helical winding angle and the thickness of a hoop layer. The finite element program MSC NASTRAN was used to predict the buckling and failure load. The results of the study confirm that the microgenetic algorithm can successfully optimize the stiffened composite cylinders. It was also found that some of the stiffened cylinders may experience static failure before buckling and the frame can replace the role of the hoop winding layer.