Abstract: The significance of the compressive densification strain to the evaluation of energy absorption properties is analyzed. The evaluation equation of compressive densification strain of paper honeycombs is modeled by introducing the instantaneous and relative density of paper honeycombs. The results of many experiments of paper honeycombs with different structure factors show how geometry aspects of hexagonal paper honeycombs, e.g. the thickness and length of honeycomb cell-wall and the drawing ratio of hexagonal honeycomb, affect the compressive densification strain of the paper honeycombs. With the increase of cell-wall thickness, the densification will reduce; with the increase of cell-wall length, the densification will increase; with the increase of thickness-length ratio of cell-walls, the densification will reduce; with the increase of drawing ratios, the densification will reduce; when the drawing ratio is 1, the compression densification is up to the maximum. The experiment results agree with the evaluation equation, and when the instantaneous and relative density is almost 0.39, the densification appears. The evaluation equation applied to the five-layer corrugated paperboard shows it also can be used for other structure honeycomb materials. The equation is universal.

Key words: Compression, Evaluation, Densification strain, Energy absorption, Paper honeycombs