Filament wound structures such as pressure tanks, pipes and motor cases of rockets are widely used in aerospace applications. The determination of a proper winding angle and thickness is very important to decrease manufacturing difficulties and to increase structural efficiency. In this study, possible winding angles considering the slippage between a fiber and a mandrel surface are calculated using the semi-geodesic path equation. The fiber angle difference through the thickness was quantified for several design parameters, such as helical winding thickness and angle. In addition, finite element analyses using ABAQUS were performed to predict the behavior of filament wound structures considering continuous change of the winding angle and thickness at the dome part due to fiber built-up near the metallic boss. A user subroutine, ORIENT was coded to impose the change of winding angles to each solid element. Another user subroutine, UMAT was also implemented to consider the material non-linear behavior which was induced from the failure. Water-pressuring tests of the ASTEB and a 3rd stage motor case were performed to verify the analysis procedure. The strain gages and fiber optic sensors were attached on the surface to measure the fiber directional strain. Progressive failure analysis predicted the burst pressure a little bit higher than the experiment and the weakest region of the motor case very well. The effect of reinforcement was also studied to increase its performance. From the verified analysis methods, study of the substitution of a hybrid tank for a metal tank by filament winding was performed.
