Compressive Behavior of Fiber-Reinforced Honeycomb Cores

Honeycomb core sandwich panels have found extensive applications particularly in the aerospace and naval industries. In view of the recent interest in alternative, yet strong and lightweight materials, honeycomb cores are manufactured from sisal fiber-reinforced polypropylene (PP) composites and the out-ofplane compressive behaviour of these cores is investigated. The cell wall material is modeled as a linear elastic, orthotropic plate/lamina and also as a linear elastic, quasi-isotropic material. The failure criteria for the reinforced honeycombs are theoretically developed. Failure maps that can be used for the optimal design of such honeycombs are constructed for a wide range of honeycomb densities. The results indicate a significant improvement in the load carrying capacity of the honeycomb cores after fiber reinforcement.