基于芯条胶粘弹性本构的芳纶纸蜂窝拉伸孔格形态研究

Study on stretched aramid honeycomb cell structure based on the viscoelastic constitutive model of adhesive

拉伸工艺是影响芳纶纸蜂窝孔格形态最关键的工序之一。本文基于纳米压痕法确定了芯条胶粘弹性力学本构关系,建立了芳纶纸蜂窝双边拉伸工艺有限元模型。通过蜂窝拉伸-保载实验验证了该模型的有效性。研究发现,芯条胶的应力松弛行为导致了蜂窝两端孔格内切圆直径增大,使蜂窝中部孔格内切圆直径减小。同时,在保载过程中纸-胶粘接处孔格粘结圆角半径减小导致蜂窝孔格内角减小。最后,基于该有限元模型探索了涂胶工艺参数对拉伸后蜂窝孔格尺寸的影响规律。研究表明,涂胶宽度和涂胶厚度的增加会导致蜂窝孔格内切圆直径的减小,而蜂窝孔格内角仅受涂胶宽度的影响,随涂胶宽度的增加而增大。

Stretching process is one of the critical procedures that affect the honeycomb cell structure of Aramid honeycomb.In this study,the viscoelastic constitutive relationship of node bond adhesive was determined by a fitting method based on nanoindentation,and a finite element model of honeycomb biaxial stretching process was established.The validity of the model was verified by the honeycomb stretching-holding experiment.The study found that the stress relaxation behavior of the adhesive caused an increase in the radius of the inscribed circles at both ends of the honeycomb and a decrease in the middle.Meanwhile,during the holding process,the node bond adhesive fillet radius decreased,leading to a decrease in the internal angle of the honeycomb cell.Finally,the influence of gluing process parameters on the size of honeycomb cell after stretching was explored based on the finite element model.The study showed that the increase in gluing width and thickness would lead to a decrease in the diameter of the inscribed circle of the honeycomb cell,and the honeycomb cell's internal angle was only affected by the gluing width,which increased with the gluing width.