Analysis of filament wound composite structures considering the change of winding angles through the thickness direction

In this study, filament winding patterns were calculated using a semi-geodesic fiber path equation for an arbitrary surface. Because the fiber path depends on the surface where fibers are wound, the winding angle varies in the longitudinal and thickness directions of a wound structure. The fiber angle difference through the thickness was calculated for several design parameters, such as helical winding thickness and angle. Finite element analyses were performed considering the change of winding angles through the thickness by a commercial FEA code, ABAQUS. A user subroutine, ORIENT, was coded to impose the change of winding angles to each solid element. Water-pressuring tests were performed for an advanced standard test evaluation bottle (ASTEB). The results of the finite element analysis considering geometrical nonlinearities were verified with the experimental data.