Crushing behavior of hybrid hexagonal/octagonal cellular composite system: Aramid/carbon hybrid composite

Abstract

In the current paper a series of experiments were conducted to assess the crashworthiness of cellular hexagonal/octagonal composite device. Each device composed of 6 cells of carbon fiber reinforced composite (CFRP). Different arrangements of the octagonal and the hexagonal cells were studied. All the configurations were filled with foam. The main objective of the current paper was to examine the effect of using the aramid/epoxy instead of the carbon/epoxy layers to pack the device. The specimens were tested under quasi-static compression loading up to complete crushing. The results showed that the packing material did not have a significant effect for the case of all hexagonal open cells. For the other configurations, introducing the aramid/epoxy instead of the carbon/epoxy showed improvements in the stroke efficiency, the crush load stability, the average crushing load, the energy absorbed and the specific energy absorption. In order to understand the mechanisms that led to this improvement, the packing material were examine after crushing using an optical microscope and a scanning electron microscope (SEM). For the carbon/epoxy, the images showed many failure mechanisms whereas, for the aramid/epoxy, only delamination was noted.