Compression behaviour of ZPR tubular structures under axial and oblique loads

Abstract

ABSTRACT The expansion of lattice-structured tubular stent causes scaffold foreshortening and artery migration during implantation. Based on stent foreshortening attitudes, studies were carried out on hybrid lattices considered Zero Poisson’s Ratio (ZPR) behaviour of arrow, auxetic, and honeycomb unit cell combinations. This paper investigates the energy performance of four ZPR tubular structures inspired by hybrid stent shapes under axial and oblique impact. At the beginning of the workflow of the study, the buckling control of tubular structures was performed using the numerical model. The compression test was performed by 3D printing of the ZPR structure, which was verified to remain uniform under axial loading. The results show that hybrid (H) tubular structures that include ZPR unit cells with different configurations have higher energy absorption and higher crushing force efficiency (CFE) under oblique impact. When the oblique angle is increased, all ZPR tubular structures are unstable from 20 to 40 mm deformation distances due to moving plate compression. H1 has a better CFE value than the other two ZPR configurations when crushed under oblique load. Furthermore, ZPR tubular structures have great advantages for axial loads without buckling behaviour.