3D printing auxetic draft-angle structures towards tunable buckling complexity

Abstract

With the development of 3D printing technology, auxetic structures have attracted extensive attention due to their unusual mechanical properties. In this study, we design a 3D printed auxetic structure using 2D draft angles to achieve a tunable out-of-plane double hyperbolic buckling behavior by effectively continuously varying stiffness across thickness. The influences of radii and draft angles on the buckling behaviors of the 3D printed draft-angle auxetic structures are studied by finite element method (FEM). The constitutive relationships between stress, strain, radius, and draft angle have been formulated and discussed to identify the working principle behind the mechanical performance of draft-angle auxetic structures. Finally, the buckling behavior is modelled by a laminate structure, and the accuracy of these analytical results has then been verified by experiment. This study is expected to provide a design guideline for achieving tunable buckling behavior of auxetic structures via the novel stress mismatch of draft angles and thus continuously varying stiffness along the thickness direction. The current work constitutes an initial attempt to realize the tunability of the 3D out of plane deformation of 2D plane structures under in-plane compression.

Programmable cell unit arrangement of 3D printing mechanical metamaterial undergoing tailorable local instability

“…The maximum load was 10 kN at room temperature. The preload was 0.1 N, under a loading rate of 5 mm min −1 and maximum compression displacement of 12 mm [40,41]. 21 printed structures had been prepared for the experimental measurements.…”

Optimization of Environment-Friendly and Sustainable Polylactic Acid (PLA)-Constructed Triply Periodic Minimal Surface (TPMS)-Based Gyroid Structures

“…Overall, the study demonstrated that yarn properties and structural variables significantly impact the auxetic behavior of the structure. Liu et al [ 12 ] explored the design of 3D auxetic structures that possessed unique mechanical properties. They designed a structure with 2D draft angles to achieve adjustable out-of-plane buckling behavior (collapsing inwards).…”