Periodic truss-lattice materials, especially when combined with current additive manufacturing techniques, are attracting attention in lightweight material engineering. As a member of the elementary cubic truss family, the simple-cubic truss lattice possesses the highest stiffness and strength along the principal directions and plays an important role in load-bearing mechanical metamaterials. High anisotropic mechanical properties and low resistance to buckling loading and shearing loading, however, limit its use in energy absorption. Here, we present a class of simple-cubic closed tubular lattice with limited loading direction dependence along with high mechanical properties and irregular stable post-yield response. The fabrication of its complex structure was made possible by direct laser writing at the microscale. Experiments and simulations demonstrate that both the elastic modulus and the yield strength of the simple-cubic closed tubular lattice are significantly larger than those of the simple-cubic truss lattice, regardless of the loading direction. At a relative density of 0.1 and compared to the truss lattice, the closed tubular lattice can absorb respectively 4.45 times and 6.14 times as much energy along directions [100] and [110]. The average normalized Young’s modulus and yield strength are respectively 28% and 53% larger than those of the most outstanding shellular metamaterial with the same mass. Such excellent mechanical properties make it a potential candidate for applications to load-bearing and energy absorption.

周期性桁架-晶格材料，尤其是与当前的增材制造技术相结合时，在轻质材料工程中引起了人们的关注。作为基本立方桁架家族的一员，简单立方桁架晶格沿主方向具有最高的刚度和强度，在承载机械超材料中发挥着重要作用。然而，高各向异性机械性能和低抗屈曲载荷和剪切载荷限制了其在能量吸收中的应用。在这里，我们提出了一类简单立方封闭管状晶格，具有有限的加载方向依赖性以及高机械性能和不规则稳定的屈服后响应。其复杂结构的制造是通过微尺度的直接激光写入实现的。实验和模拟表明，无论加载方向如何，单立方封闭管状晶格的弹性模量和屈服强度均显着大于单立方桁架晶格的弹性模量和屈服强度。在相对密度为 0.1 时，与桁架格子相比，封闭管状格子沿方向 [100] 和 [110] 可以分别吸收 4.45 倍和 6.14 倍的能量。平均归一化杨氏模量和屈服强度分别比相同质量的最出色的壳超材料大 28% 和 53%。如此出色的机械性能使其成为承载和能量吸收应用的潜在候选者。