Mechanical behavior and energy absorption of graded honeycomb materials under out-of-plane dynamic compression

Honeycomb materials are of good energy absorption performance under impact loading. To further improve their specific energy absorption and crash load efficiency, a new honeycomb model is proposed here, of which one geometry parameter or material parameter varies gradually along the honeycomb thickness direction. Based on the hexagonal configuration, the mechanical behavior and energy absorption of honeycombs with cell wall thickness or yield strength of based material varying gradually along the thickness direction are investigated under dynamic compression. It is demonstrated that by adopting proper grading exponents, honeycomb materials with graded distribution of cell wall thickness or yield strength of based material can bring down the initial peak stress as well as increase the specific energy absorption (SEA) and crash load efficiency (CLE). These results may provide new ideas to optimal design of honeycomb materials for energy absorption.