Study On Dynamic Properties Of Honeycomb Sandwich Panels

As a type of lightweight structural material, metal honeycomb sandwich structure has been widely used in aerospace, shipbuilding, automobile manufacturing, and many other fields due to its superior performances. Considering usages of honeycomb sandwich panels in aircraft, satellites and other structures where to bear out-plane loads, it is siginficant to study the out-plane mechanical properties, especially dynamic mechanical properties under the out-plane impact loads.In this paper, under the existing theories and researches, the aluminum alloy honeycomb sandwich panels with hexagonal cell were selected as specimens, its mechanical properties under out-plane static loads and impact loads were studied; the non-destructive testing of the honeycomb panel's defect and the damnification of the stretched honeycomb panel had been performed with the electronic speckle shearing interferometry, and many effective results were abtained.Stress-strain curves of aluminum alloy honeycomb sandwich under quasi-static compression and dynamic impact loads were obtained through uniaxial quasi-static compression and dynamic impact experiments. It is shown in the static and dynamic compression stress-strain results, the curve has a typical three stages form. There are elastic stage, plastic stage, and close-grained stage after crushing. These results were compared well with the numerical simulation results, at the same time, it can be concluded from the test results that this kind of aluminum alloy honeycomb panel is rate dependent material and dynamic strength is 7MPa higher than static compression strength. Observing the some pictures of specimens after impacting with stereo microscopic, it can be seen that this kind of material has the excellent properties of energy absorption.There are some defects such as debonding, crumpled cellular walls, or splited nodes when the honeycomb sandwich panels were produced. The existence of these defects will reduce the structural strength and stiffness, reduce usfull time. Therefore, the non-destructive examination of the honeycomb sandwich panel is significant. With electronic speckle shearing interferometry, the aluminum alloy honeycomb sandwich panels were examined in this paper. The thermal load and the phase-shifting technology were used in the paper, and the speckle fringe patterns of the aluminum alloy honeycomb sandwich panels with defects and with tensile damage were obtained. Through the application of the electronic speckle shearing pattern interferometry and the results of the tests in this paper, ESSPI has a great advantage in the non-destructive examination of the honeycomb panels.