Influence of Honeycomb Cellular Meso-structure on Frontal Crash Analysis for Passenger Vehicle

Frontal collisions account for majority of car accidents. Various measures have been taken by the automotive OEMs’ with regards to passive safety. Honeycomb meso-structural inserts in the front bumper have been suggested to enhance the energy absorption of the front structure which is favorable for passive safety. This paper presents the changes in energy absorption capacity of hexagonal honeycomb structures with varying cellular geometries; under frontal impact simulations. Honeycomb cellular metamaterial structure offers many distinct advantages over homogenous materials since their effective material properties depend on both, their constituent material properties and their cell geometric configurations. The effective static mechanical properties such as; the modulus of elasticity, modulus of rigidity and Poisson’s ratio of the honeycomb cellular meso-structures are controlled by variations in their cellular geometry.

While the crushing responses in terms of energy absorption and densification of strains have been extensively researched and reported, a gap has been identified in the generalized study of honeycombs with controlled varying of geometric parameters. Unit assembly model technique is used to evaluate the performance of the honeycomb inserts in frontal impact simulations. This paper addresses the study through a series of finite element (FE) simulations where the cell angles and the wall thicknesses are varied. Sensitivity analysis of absorbed energy has been done; to determine the parameters enhancing the crushing energy absorption of honeycombs.