Analysis of tensile behaviour of hyperelastic auxetic cellular materials with re-entrant hexagonal cells

Abstract

Hyperelastic auxetic cellular materials are negative Poisson’s ratio (NPR) and show transverse expansion when stretched and lateral contraction when compressed. The influence of the direction of force on the auxetic property, effect of cell angle on Poisson’s ratio, buckling property of RH structures has been discussed in this article. The results show that: re-entrant hexagon (RH) structure never shows non-auxetic behaivour when it is subjected to load vertical force while it shows non-auxetic performance when the force reach a certain value when it is subjected to load transverse force. When stretched in the vertical direction and within a certain displacement, RH structures with smaller angle requires smaller force. Meanwhile, RH structure with smaller angle has more obvious auxetic property. When the RH model was stretched, its Poisson’s ratio first decreases and then increases. Buckling occurs when RH is subjected to load longitudinally, and as the total width of the simple increases, the number of buckling curves increases.