AUXETIC TWO-DIMENSION MATERIAL WITH MODIFIED PEANUT PATTERN

Auxetic materials with negative Poisson's ratio are alternatively used in engineering applications. In engineering design, light-weight auxetic material with low stress and negative Poisson's ratio is the main topic. The peanut pattern can be reduced the weight by decreasing the equivalent density. The unit cell of the peanut pattern lattice can be drilled with four circle holes. In this study, the auxetic two-dimension material with modified peanut pattern is used to study the effect of the pattern geometric shape and the equivalent density on the stress and the Poisson's ratio. A four-circle punched pattern has been designed with the original peanut pattern. The equivalent density will be changed by varying their radius lengths. The results show that, the stress and the Poisson's ratio can be reduced by increasing the radius length. In the other words, by decreasing the equivalent density, the stress and the Poison's ratio is decreased. The parabolic relationship between the radius length and the stress is found with R-square value more than 0.95 similar to the relationship between the radius length and the Poissong's ratio.