AUXETIC TWO-DIMENSION MATERIAL WITH MODIFIED PEANUT PATTERN

Abstract

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.