标题： 双网络启发的机械超材料 显示英文标题

标题： Double-network-inspired mechanical metamaterials

摘要： 机械超材料以其在低密度下实现高刚度和强度的能力而著称，这通常以低延展性和可拉伸性为代价——这是材料中的一个持续权衡问题。 相反，诸如双网络水凝胶的材料具有相互渗透的柔性和刚性聚合物网络，并表现出前所未有的高刚度和可拉伸性的组合，从而具有卓越的韧性。 在这里，我们通过将单块桁架（刚性）和编织（柔性）组件整合到超材料结构中，提出了双网络启发的（DNI）超材料，与纯编织和桁架结构相比，它们的刚度和可拉伸性分别提高了十倍。 非线性计算力学模型阐明，这些DNI超材料中增强的能量耗散源于两种网络之间纠缠导致的摩擦耗散增加。 通过引入通常会降低机械性能的内部缺陷，我们展示了通过失效分散实现了这些超材料能量耗散的三倍增加。 这项工作为开发新型超材料开辟了道路，这些超材料在高柔度范围内受到聚合物网络拓扑结构的启发。 显示英文摘要

摘要： Mechanical metamaterials are renowned for their ability to achieve high stiffness and strength at low densities, often at the expense of low ductility and stretchability-a persistent trade-off in materials. In contrast, materials such as double-network hydrogels feature interpenetrating compliant and stiff polymer networks, and exhibit unprecedented combinations of high stiffness and stretchability, resulting in exceptional toughness. Here, we present double-network-inspired (DNI) metamaterials by integrating monolithic truss (stiff) and woven (compliant) components into a metamaterial architecture, which achieve a tenfold increase in stiffness and stretchability compared to their pure woven and truss counterparts, respectively. Nonlinear computational mechanics models elucidate that enhanced energy dissipation in these DNI metamaterials stems from increased frictional dissipation due to entanglements between the two networks. Through introduction of internal defects, which typically degrade mechanical properties, we demonstrate an opposite effect of a threefold increase in energy dissipation for these metamaterials via failure delocalization. This work opens avenues for developing new classes of metamaterials in a high-compliance regime inspired by polymer network topologies.