Development of 3D Printed Honeycombs for Crash Mitigation Applications

Abstract

Honeycomb structures have been studied thoroughly to understand their in and out-of-plane mechanical properties. The ability of honeycombs to effectively absorb energy makes them ideal for usage in crash mitigation, particularly for helicopters and automobiles. Currently, when crushed by a dynamic load, there is an impulse in force prior to a steady absorption – which could be detrimental in such crash mitigation applications. In this study, 3D printed honeycombs are investigated for subsequent crush efficiency with quasi-static and dynamic crush tests. 3D printing, rather than conventional manufacturing, allows for structural modifications within the honeycomb that influence its force-displacement profile. Buckling initiators on the face and/or vertex of honeycombs should reduce the initial peak stress and increase the strain at which densification, the point at which the stress once again increases, begins. The experiment is not complete, but thus far, buckling initiators have proven to decrease the initial peak stress of tested honeycombs. Future directions for the project include testing honeycombs of other materials with buckling initiators, and the implementation of variations of current buckling initiator designs.