Hayati - MS student in mechanical engineering, University of Zanjan, mechanical Engineering department
Alireza Eslamian - Instructor, Zanjan Branch, Islamic Azad University, Zanjan, Iran

In the present work, implementation of FG cores in sandwich panels to enhance the energy absorption capacity of sandwich panels and reduce the risk of delamination between core and walls is studied numerically. Aforementioned sandwich panel is modeled and analyzed using ANSYS software which consist of two external and one medial aluminum layers that are bonded together with FG cores. The FG core is assumed as a special NOMEX composed of functionally graded Phenolic resin foam reinforced with Aramid fibers. A rectangular piece of such panel is modeled and loaded according to the ASTM standard. The shear stress along the thickness of the panel as a primary cause of delamination and also the overall amount of absorbed energy, for different load-to-weight ratios are extracted. Results showed that average shear stress at the interface of the FG core and the aluminum walls is very low compared to the conventional cases which may be a pleased sign of reduced risk of delamination. It is also deduced that the energy absorption capacity of FG-core sandwich panels shall be increased considerably in expense of 25% excess weight per area values. Since modal analysis forecast a negligible decrease in natural frequencies of FG-Core panels against conventional ones, it could be expected that the use of FG-core concept will not disturb the quite level of sandwich panels.

FG-core panel, ASTM standard, risk reduction of delamination, energy absorption capacity, quite level