Advances in additive manufacturing have enabled a new generation of materials with advantageous properties inherent to their architecture. Recently, architected materials with periodic arrangements of plates, called plate-lattice materials, have been developed to reach theoretical least upper bounds for stiffness and strength of isotropic materials. This work investigates the buckling behavior of several plate-lattice architectures with relative densities between 0.5% to 25% when subjected to uniaxial compression. Finite element unit cell models with shell elements and periodic boundary conditions are used to simulate the buckling and post-buckling behavior of plate-lattices made from an elastic-perfectly plastic parent material. Five plate-lattice architectures with cubic symmetry are investigated — three anisotropic architectures (simple cubic, body-centered cubic, face-centered cubic) and two isotropic architectures (simple cubic and body-centered cubic combination, simple cubic and face-centered cubic combination). Geometric imperfections of varying amplitude are applied to determine the imperfection sensitivity of these plate-lattice materials, and to calculate their buckling knockdown factors. Consistent with the behavior of the elastic–plastic plate building blocks that comprise the lattice, this investigation reveals that plate-lattice materials are generally imperfection insensitive when their constituent plates become thinner and first bifurcation occurs in the elastic range away from the yield stress. When this occurs, the initial post-buckling behavior is stable and the ultimate strength can be many times higher than the initial buckling stress.

增材制造的进步使新一代材料具有其结构固有的优势。最近，已经开发出具有周期性排列的板的建筑材料，称为板晶格材料，以达到各向同性材料的刚度和强度的理论最小上限。这项工作研究了相对密度在 0.5% 到 25% 之间的几种板格结构在受到单轴压缩时的屈曲行为。具有壳单元和周期性边界条件的有限元晶胞模型用于模拟由完全弹塑性母体材料制成的板格的屈曲和屈曲后行为。研究了五种具有立方对称性的板格结构——三种各向异性结构（简单立方、体心立方、面心立方）和两种各向同性结构（简单立方和体心立方组合、简单立方和面心立方组合）。应用不同幅度的几何缺陷来确定这些板点阵材料的缺陷敏感性，并计算它们的屈曲击倒系数。与构成晶格的弹塑性板构建块的行为一致，这项研究表明，当组成板变薄并且第一次分叉发生在远离屈服应力的弹性范围内时，板-晶格材料通常对缺陷不敏感。当这种情况发生时，初始后屈曲行为是稳定的，最终强度可能比初始屈曲应力高很多倍。面心立方）和两种各向同性结构（简单立方和体心立方组合，简单立方和面心立方组合）。应用不同幅度的几何缺陷来确定这些板点阵材料的缺陷敏感性，并计算它们的屈曲击倒系数。与构成晶格的弹塑性板构建块的行为一致，这项研究表明，当组成板变薄并且第一次分叉发生在远离屈服应力的弹性范围内时，板-晶格材料通常对缺陷不敏感。当这种情况发生时，初始后屈曲行为是稳定的，最终强度可能比初始屈曲应力高很多倍。面心立方）和两种各向同性结构（简单立方和体心立方组合，简单立方和面心立方组合）。应用不同幅度的几何缺陷来确定这些板点阵材料的缺陷敏感性，并计算它们的屈曲击倒系数。与构成晶格的弹塑性板构建块的行为一致，这项研究表明，当组成板变薄并且第一次分叉发生在远离屈服应力的弹性范围内时，板-晶格材料通常对缺陷不敏感。当这种情况发生时，初始后屈曲行为是稳定的，最终强度可能比初始屈曲应力高很多倍。