Dynamic and quasi-static deformation of aluminium honeycomb sandwich panel in three point bending

In this research, the dynamic and quasi-static deformations of aluminium honeycomb sandwich panels in three point bending were investigated experimentally. The load, the deflection of a loading point and the strain response of the rear surface plate at various locations were measured. A peak load caused by local plastic buckling of the cores just under the loading point appeared in the early stage of both dynamic and quasi-static bending. The peak load observed at dynamic rates was about $10\sim20$ % greater than that obtained from static tests. The absorbed energy in the dynamic deformation was also larger than that obtained in static tests. From the change of the strains of the rear surface plate, it was found that the third or higher deformation mode occurred during the early stage of dynamic bending, although only the first mode was observed in static tests. The difference of the bending mode may be one of the principal reasons of greater peak load and absorbed energy in dynamic bending