فاطمه حسن پور رودبنه

In this paper, concentrated and distributed compressive loading quasi-static tests were conducted on sandwich structures with empty and foam filled honeycomb core. The sandwich structure used in this research were formed by aluminum plate and aluminum 5052 honeycomb structure. Foam used to fill the honeycomb structure was polyurethane foam with a density of 137.13 kg / m3.Concentrated loading quasi-static tests were performed by flat ended penetrator with a diameter of 10 mm and universal machine. Also distributed loading quasi-static tests were carried out by universal machine. In distributed loading, force is applied uniformly to the entire structure surface. Displacement rate was 2 mm/min for both types of loading. The purpose of this paper was to study the filler material effect on energy absorption and destruction shape of sandwich structure, as well as comparison of the two types of loading in unfilled and foam filled honeycomb core sandwich panels. The results of quasi-static tests showed that filler material has positive effects on increasing energy absorption in both concentrated and distributed loading. Polyurethane foam as filler material of honeycomb structure used in sandwich panel core increase specific absorbed energy of sandwich panel with foam filled core proportion to empty honeycomb core sandwich panel structure in concentrated and distributed loading by 6% and 29% respectively.

In this paper, the interaction between aluminum facing and honeycomb structure in the quasi-static and the impact loading has been investigated experimentally. The structural elements used in this research were aluminum plate, aluminum 5052 honeycomb structure. The quasi-static penetration tests and ballistic impact experiments were performed on aluminum plate, honeycomb structure and sandwich panel by flat ended penetrator and flat ended projectile respectively. The failure mechanisms, the ballistic limit velocities, the absorbed energies due to penetration, the damage modes and some structural responses were studied. Also, the effect of interaction between aluminum facing and honeycomb structure in the quasi-static penetration and the ballistic impact response in this honeycomb sandwich panel was discussed and commented upon. Comparing energy absorption in these structures showed that the amount of absorbed energy by the sandwich panel with honeycomb core is more than the absorbed energy by the aluminum plate and honeycomb structure in the quasi-static penetration. These results indicated, when the honeycomb structure was used as the core of sandwich panel, resulted in increasing of the stiffness and the strength of the sandwich panel. The ballistic impact results showed that the absorbed energy and the ballistic limit velocity in the sandwich panel compared with the individual components was increased. Therefor the sandwich structure can be used as a suitable energy absorber.