纸蜂窝压缩密实化应变评估

Evaluation of Compressive Densification Strain of Paper Honeycombs

分析纸蜂窝压缩密实化应变对纸蜂窝吸能特性评估的重要性,引入纸蜂窝压缩瞬时相对密度的概念,从理论上建立纸蜂窝压缩密实化应变评估方程,并做了不同结构参数的纸蜂窝准静态压缩试验,试验结果表明纸蜂窝胞壁厚度、边长和纸蜂窝的拉伸率等结构因素对压缩密实化应变均有一定的影响:纸蜂窝压缩密实化应变随胞壁的厚度δ的增大而减小;随蜂窝胞元边长l的增大而增大;随蜂窝胞壁厚跨比δ/l的增大而减小;随其拉伸率r的增大,先增大后减小,在拉伸率为1时,其压缩密实化应变达最大值;纸蜂窝结构因素对其压缩密实化应变的影响与文中的理论公式是相符的,纸蜂窝的密实化应变与其相对密度近似呈反比例关系,当纸蜂窝的瞬时相对密度为0.39左右时,纸蜂窝压缩趋于密实化。将该评估方程用于五层瓦楞纸板的压缩密实化过程评估表明它也可用于其他结构形式纸蜂窝材料的压缩密实化应变评估,具有一定的普适性。

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.