Mechanical characterization of a novel thickness gradient auxetic tubular structure under inclined load

A novel gradient auxetic tube is proposed, which is characterized by a gradual change in cross-section from top to bottom. Based on a verified numerical model, the mechanical properties of gradient auxetic tubular structure and traditional auxetic tubular structure under axial and inclined loads are analyzed through the finite element method. The results show that gradient auxetic tubular structures have higher overall stability, higher energy absorption and higher specific energy absorption under inclined loads. When the difference of wall thickness between the upper and lower sections of the gradient auxetic tubular structure is larger, the advantages of high energy absorption and specific energy absorption would be more prominent. Due to their excellent energy absorption properties, thickness gradient auxetic tubular structures have great potential for applications in civil engineering, vehicle crashworthiness and protective infrastructure.