Hierarchical auxetic structures inspired by natural cellular structures possess negative Poisson Ratio (PR) due to their inherent geometric constraints. With the advancements in additive manufacturing (AM), high-performance computing and shape optimization algorithms, developing high-performance auxetic structures has emerged as an active area of research. Recently, a sinusoidal design of repeating cell with smooth and curved members, referred to as Double-U Hierarchical (DUH) structure, has been shown to perform better than the traditional Double-V Hierarchical (DVH) structure. However, the option of improving the existing DVH design is not explored so far. In the present work, we fill this research gap by incorporating curviness and roundness to its unit cell and evaluating its performance using finite element analysis. We call our improved version of DVH as DRVH (Double-Rounded-V Hierarchical) auxetic structure. The combination of straightness and roundness of DRVH members not only provides more room for absorbing impact energy than DUH design but also reduces stress concentration and enhances auxetic behaviour and static collapse stress. To confirm this, future work will be carried out in this direction by running experiments and more analyses on DRVH auxetic structure.

PDF (Download Full text)

| Download Citation (XML)