Design strategy for auxetic dual helix yarn systems

Abstract

Auxetic materials exhibit negative Poisson’s ratio and they expand in the lateral direction on stretching. In the present study, the auxetic behavior of dual helix yarn (DHY) system has been predicted through energy minimization approach. It has been proposed that the interplay between the bending and tensile energies is responsible for the generation of the auxetic behavior in a typical DHY system. The DHY system can be potentially tailored for a large negative Poisson’s ratio under a broader “window” of axial tensile strains by simply downsizing the diameter of carbon based wrap yarn from micron to nanoscale. A comparison has been made between the theoretical and experimental results obtained from the literature.