Understanding the effect of local material property fluctuation on the overall structural properties of cellular structures is not only important for more effective designs, but also critical for their adoption in load-bearing applications. In this work, an analytical modeling approach based on direct stiffness method was adopted, which allows for the implementation of heterogeneous material imperfection at full-scale cellular structure level. Three representative 2D cellular designs including auxetic, diamond and triangular structures were modeled and analyzed. The material property imperfection was represented by 3 levels of variabilities (2%, 5% and 10%) for both elastic modulus and strength, defined at local cellular element level. Experimental verification using Ti6Al4V cellular structures fabricated via laser powder bed fusion additive manufacturing demonstrated the potential of the established model in providing accurate predictions to the mechanical property variability of the cellular structures. In addition, the results also revealed new insights into the topology-material imperfection coupling relationships for the cellular structures. The auxetic structures exhibit the lowest material imperfection tolerance, whereas the stretching-dominated triangular structures exhibit the highest material imperfection sensitivity. The contribution of elastic modulus and ultimate strength imperfections at material level to the overall structural performance were established. Ultimately, this work could help “re-establishing” the fundamental understanding of design factors for finite-size cellular structures with imperfect material properties.

理解局部材料特性波动对蜂窝结构整体结构特性的影响不仅对于更有效的设计很重要，而且对于在承重应用中采用它们至关重要。在这项工作中，采用了基于直接刚度方法的分析建模方法，该方法可以在全尺寸单元结构水平上实现异质材料缺陷。建模和分析了三种典型的2D蜂窝设计，包括膨胀，菱形和三角形结构。材料性能缺陷由弹性模量和强度的3种变化水平（2％，5％和10％）表示，在局部细胞单元水平定义。使用通过激光粉末床熔合增材制造制造的Ti6Al4V蜂窝结构进行的实验验证表明，建立模型的潜力可为蜂窝结构的机械性能变化提供准确的预测。另外，结果还揭示了对细胞结构的拓扑-材料缺陷耦合关系的新见解。膨胀结构表现出最低的材料缺陷容忍度，而拉伸为主的三角形结构表现出最高的材料缺陷敏感性。确定了材料水平的弹性模量和极限强度缺陷对整体结构性能的贡献。最终，