Heuristic Design of Mechanical Metamaterials with High Load-bearing and High Energy-absorption Integration

Recent tendencies of lightweight and multifunction integration in aerospace, automobile, and national defence have raised urgent demands for materials that simultaneously possess high load-bearing ability and high energy-absorption capacity. In this seminar, I will present our recent work on the design of advanced lightweight lattice materials through inspiration from bio-skeletons, microstructure of cystals, and four-dimensional hypercubes. As a typical example, a bio-inspired multi-feature lattice material is proposed that integrates the features of the double-diagonal reinforcement in deep-sea glass sponges and the curled fibres in luffa pulp. The proposed lattice simultaneously possesses high strength, high energy absorption, considerable toughness, as well as controllable deformation patterns. The second example is the micro-inspired lattices that are developed by introducing the polycrystalline-like interfaces or the heterogeneous second-phase cells into the conventional lattice materials. The proposed lattice materials exhibit significant enhancement of the mechanical properties due to the hindering effect of the introduced heterogeneities on the shear band formation and propagation. The third example is the hypercube lattice that is inspired from the four-dimensional hypercube (or Tesseract in science-fiction film). The proposed structure can realize simultaneous isotropic stiffness and isotropic strength, and has promising potential for mechanical-acoustic integrated performance. This work is aimed at providing pathways for the design of new lattice materials with outstanding performances in multiple application scenarios including load-bearing, blast protection and accoustic attenuation.