A cylindrical shell with varying fiber orientations was manufactured using advanced fiber placement technology. The small dimensions of the shell required a small turning radius, causing puckers to form during lay-down which were not visible in the end product. On a product with larger dimensions a larger turning radius can be used to obtain the same stiffness variation, resulting in less puckering. The amount of small triangular gaps and overlaps was minimized by using a 50 percent coverage parameter, while long gaps between parallel courses were avoided by adjusting the shift between courses. The minimum cut length requirement was taken into account during design, preventing any deficiencies. Cutting tows on the outside of a steered course caused problems, because the outer tows were not restrained and thus followed a geodesic path. In future designs this can be avoided by not allowing tows to be cut on the outside of a turn. Furthermore increasing the maximum course width will result in less tow drop areas. Currently a modal test is being carried out on both the variable-stiffness shell and the traditional shell, after which they will be prepared to be structurally tested in pure bending. Comparisons between analytical and experimental results will be published for both tests.
Design and manufacture of a variable-stiffness cylindrical shell
Entwurf und Herstellung einer zylindrischen Schale mit variabler Steifigkeit
2009
8 Seiten, 9 Bilder, 2 Tabellen, 8 Quellen
Aufsatz (Konferenz)
Datenträger
Englisch
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