A novel rotating petal quadrilateral metamaterial with tunable plateau stresses

Negative Poisson’s ratio (NPR) metamaterials with multi-plateau responses have attracted increasing attention owing to their unique mechanical behavior and excellent energy absorption capacity. In this study, a novel rotating petal quadrilateral metamaterial (RPQM) with a dual-plateau stress-strain response was proposed by integrating rigid rotating square units with biomimetic petal-like structures. The RPQM was fabricated by selective laser melting based on a hybrid design strategy. The quasi-static mechanical behavior was validated experimentally and numerically, whereas its dynamic response was investigated through numerical simulations and theoretical analysis. Research results show that the specific energy absorption (SEA) increases with the side length l 1 of the quadrilateral unit and reaches a maximum at l 1 = 3 mm. The deformation mechanism governing the dual-plateau response under quasi-static compression was clarified through microscale analysis of unit-cell deformation. A theoretical model was further developed to predict the plateau stress under both quasi-static and dynamic loadings, and good agreement was observed between the theoretical predictions and the finite element results. Parametric analysis indicates that the dual-plateau stress responses and SEA can be effectively tuned by varying the topological parameters. Under the quasi-static conditions, the SEA of the RPQM is at least 19.65% higher than that of other auxetic structures. These findings will provide a useful basis for the design and optimization of auxetic metamaterials with controllable mechanical properties.