An auxetic tubular structure with tuneable stiffness [一种刚度可调控的负泊松比管状结构]

Auxetic metamaterials have attracted great attention due to their indentation resistance, shear resistance, synclastic behaviour, fracture toughness and energy absorption properties. As one branch of auxetics, the tubular structure with negative Poisson's ratio has potential to be used in engineering, medical treatment, vehicle and other fields. However, studies on mechanical properties of auxetic tubular structures are limited in both tension and compression in the current literature, and auxetic tubular structures tend to exhibit low stiffness ratio due to the existence of internal holes. In this paper, a novel type of auxetic tubular structure with tuneable stiffness was developed, and finite element analysis and experimental study were carried out on the parameters of different rotation modes, the degree of advanced compaction and the height of deformation zone. The results show that the stiffness of auxetic tubes with tuneable stiffness can be turned by adjusting different proportions of compaction point, and the h value can be used to reduce the error between the designed proportion and real proportion. Auxetic behaviour of the tubes with tuneable stiffness is not significantly weakened. The auxetic tubular structures with tuneable stiffness proposed in this paper bring about an innovative design concept and have good application prospects in protection engineering.