Z. Hasan, M.I. Zuardy

The combination of light weight concept with optimized structural characteristics under varying arts of load is the center of expectation in every branch of mechanical construction. Sandwich is one of the new breed that was thought to fulfill the expected purpose, inspired from the principle of natural bionic. But the expectation of science has no moral dimension and border. So although in the earlier stage the common rectangular cross-section of sandwich structure was vastly applied in secondary aerospace structure, but the need of further reducing the net weight gave impulse to think otherwise. As the primary structure has to perform under extreme load conditions, so the application of sandwich structure in primary assembly demands improved fail safe response, for example, through further development of material or structural model. The deviation from the conventional concept is the new speculation "lens shaped concept". But whether this new concept can compete with the older ones and add a new dimension in sandwich concept, whether its response under transient dynamic loading is well worth, was covered in cloud. Although the damping ability and damage resistance of lens shaped structure is theoretically estimated by the publication "Zuardy M.I., Herrmann A. S.: An advanced center box of a vertical tail plane with a side panel from CFRP foam core sandwich structure", but numerical and experimental validation of the speculation was needed to establish its reliability for primary structure. The numerical results calculated through ANSYS and LS-DYNA show, in comparison to conventional construction, the lenticular or lens-shaped sandwich structure within a definite thickness can decay the out of balance impact energy amplitude more efficiently. Even the damping of impact energy through uniform distribution of global displacement over the whole cross-section plays the key role to enrich its damage resistance. The assessment of the lens shaped structure in respect to the ratio of pristine to damaged area provides also promising perspective. This structure reaches a more decreased minimum of equilibrium energy frequently than a structure with rectangular cross-section, which remains in an energetic unbalanced state after the impact phase. This phenomenon can stimulate the damage propagation rate in a rectangular sandwich structure. The results from FEM simulation prove the reality of the speculations validated through experiments. Based on this results the construction of an Airbus next generation prototype is under observation.

Deutscher Luft- und Raumfahrtkongress 2013, Stuttgart

Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn, 2014

Conference Paper

englisch

21,0 x 29,7 cm, 11 Seiten

urn:nbn:de:101:1-2014013117552

constant ratio "1", convex phase, destructive interference, global displacement distribution, inverse proportional relationship, lenticular sandwich structure, pseudo damping, rectangular sandwich structure, transient dynamic

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31.01.2014