1 Engineering Technical College of AL-Najaf, Al-Furat Al-Awsat Technical University (ATU), Iraq.

2 Al-Farahidi University, Baghdad, Iraq.

3 University of Technology, Baghdad, Iraq.


In this paper, the strength of aircraft sandwich structure with honeycomb
core under bending load was evaluated theoretically and experimentally
based on failure mode maps. A failure mode map for the loading under
three-point bending was constructed theoretically to specify the failure
modes and corresponding load. Three point bending test for aluminum
honeycomb sandwich beam has been achieved to measure the peak load
and maximum deflection. The obtained results elucidated a good
agreement between the theoretical solutions and experimental tests, where
the error ratio was not exceeded 12%. The core height, the cell size and
the cell wall thickness were selected to explore the effect of honeycomb
parameters on the strength of sandwich structure. In order to obtain the
optimum solution of peak load and maximum deflection and energy
absorption, Response Surface Methodology (RSM) was used. Results
showed that the maximum bending load, minimum deflection, and
maximum energy absorption were found at 25 mm core height, 10 mm size
cell and 1 mm cell wall thickness. The optimal value of maximum bending
load, minimum deflection and maximum energy absorption were
1975.3415 N, 1.0402 mm and 1.0229 J respectively.