Mechanical Characteristics of Filament-Wound Pressure Vessel

Abstract

The fiberglass-reinforced composites fabricated by the filament-winding technique developed for convex pressure vessels have advantages especially in high specific strength. However, because of an analytical difficulty encountered with the arbitrary configuration and variation of anisotropic properties of shell structures, it is required to establish the analytical method of mechanical characteristics prior to its optimum design.
In the present paper, by taking up a nearly spherical pressure vessel fabricated by the in-plane or planar winding technique, an analytical approach is presented to obtain the distributions of orthotropic elastic constants by use of the lamination theory, and then the stresses and strains in a revolutionary shell by the finite element method. As an example, a 480mm diameter rocket chamber developed for the fourth stage of Lambda rocket is analysed and a good agreement with the experimental values obtained in hydrostatic tests is shown to exist.
Next, in view of the practical configuration of rocket motor chamber having junctions with adjacent stages, an analytical method of vessel structures with branching support is presented together with the constraint effects on strains in the vicinity of junction.
Lastly, the practical loading cases encountered in test firing on the ground and in flight are compared with those under hydrostatic pressure. These three cases exhibit almost the same strain distributions, suggesting the applicability of hydrostatic proof test in the laboratory to check the mechanical characteristics.