Analytical modeling of metallic honeycomb for energy absorption and validation with FEA

Abstract

Honeycomb materials possess high energy absorption characteristics and are useful for the impact protection of structural members. Various honeycomb configurations are being developed for a variety of applications. Analytical models are now available to determine the energy absorption characteristics of the regular hexagonal type of honeycomb. However, the development a parameterized analytical model that can determine the energy absorption characteristics of various honeycomb shapes is needed. In this research, a parameterized analytical model is developed for the typical honeycomb shape, and is validated using experimental and finite element analysis. Honeycomb materials exhibit strain-rate effects at impact velocities. They can have higher energy absorption during dynamic crush than during quasi-static crush. In order to determine the energy absorption of honeycomb material at higher velocity, the characterization of it must be made using high-impact testing machines, which are expensive and time-consuming. Therefore, development of an analytical model that can predict energy absorption at higher velocities is needed. Also, strain-rate coefficients must be determined for each particular type of honeycomb since the strain rate depends on the geometrical properties of the honeycomb. Therefore, strain-rate coefficients were developed for each honeycomb model in this research. The energy absorption of honeycombs at higher impact velocities was also determined using the low-velocity test, which will be useful when only low-velocity machines are available for testing honeycombs. Finally, a performance analysis was carried out using response surface methods to maximize energy absorption of the honeycomb.