The Effects of Negative Poissons Ratio and Finite Element Analysis of Polyvinyl Alcohol Hydrogel with Three-Dimension Porous Structure

Abstract

Based on the assumptions of the preparation process and the microstructure characteristics of polyvinyl alcohol hydrogel with three-dimension porous structure, and compared to the similar hexagonal honeycomb configuration, a kind of novel Centre symmetric honeycomb structure with three sorts of shapes, stack patterns evaluated is constructed. The results show that the entire structure without filling with honeycombs has the negative Poissons ratio ignoring various configuration parameters. The entire structure filling with honeycombs, the changes of the honeycombs thickness, three different arrange-square, vertical and transverse deformation modes, and the configuration parameters make the entire unit cell possess the negative Poissons ratio. When the numerical value of the unit cell thickness is less than 5μm and the honeycombs in the novel Centre symmetric structure take arrange-square shapes, if filling with circular honeycombs, the entire structure should choose the bigger values of the structure parameters R2,1 and L2, the novel Centre symmetric honeycomb structure possess the negative Poissons ratio; if filling with hexagonal honeycombs, the entire structure should choose the smaller values of the structure parameters R2,1 and L2, the novel Centre symmetric honeycomb structure possess the negative Poissons ratio.