Mechanical properties of 3D hybrid double arrow-head structure with tunable Poisson's ratio

In this study, three-dimensional hybrid double arrow-head (3D HDA) structure is proposed by combining the convex and concave quadrilateral components. Theoretical models for elastic constants of 3D HDA structure are established, which indicates that 3D HDA structure has tunable Young's modulus and Poisson's ratio by adjusting the complementary action of conventional and auxetic components. 3D printing technique is used to fabricate the 3D HDA specimens with supporting materials and the compression experiments are carried out after removing supporting materials manually to validate the accuracy of theoretical and numerical models. The crushing behaviors and energy absorption performances of 3D HDA structure are investigated and the influences of geometric parameters have been revealed for different crushing conditions. For quasi-static and low-velocity crushing conditions, the crushing plateau stress gets higher when the Poisson's ratio trends to the value of zero. While for high-velocity crushing condition, the crushing collapse transfers to layer-by-layer collapse which weakens the influence of Poisson's ratio effect. The value of plateau stress is positive correlated with the Young's modulus of structure. The proposed 3D HDA structure is highly designable for mechanical properties with stable collapse deformation, excellent ductility and better energy absorption performances which make the 3D HDA structure suitable for structural and functional applications in aerospace engineering.