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

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.