Performance‐Oriented and Deformation‐Constrained Dual‐topology Metamaterial with High‐Stress Uniformity and Extraordinary Plastic Property

The study of classical mechanical metamaterials has overwhelmingly remained at the elastic stage, while the increase in extreme speeds of vehicles and aircraft has created an urgent need and demanding requirements for excellent plasticity performance. Although some plastically deformable metamaterials exist, high initial peak stresses, short plastic strokes, and low plastic stresses limit their applications considerably. Here, an ideal malleable large-deformation metamaterial featuring high-stress levels and stability is reported. A performance-oriented multidimensional performance expansion strategy is adopted to obtain the bionic triangular corrugation-based plate lattice (TCPL) metamaterial. Then, the deformation constraint strategy that TCPL is innovatively used as the main topology with lateral expansion and buckling inhibited by the inserted enhancing topology is proposed, thus obtaining the built-in dual-topology enhanced TCPL (ETCPL). The ETCPL is again substantially strengthened in stress uniformity with almost no gradient and mechanical properties with strain energy improved by 51.56%. They are much more robust than typical multicellular materials, with the largest performance enhancement reaching 18 667.19%. In addition, the strength-density performances of both metamaterials significantly exceed the predictions of Gibson-Ashby model up to 75.2% maximum. The unprecedented performance confirms that multidimensional performance expansion strategy and deformation constraint strategy have created new design guidelines for ideal high-performance plastic metamaterials.