轻质高强点阵材料及其力学性能研究进展

点阵材料是一种新型轻质高强材料, 同时具备形状控制、致动、能量吸收和传热等多种功能. 文章综述了点阵材料的拉伸主导型设计原则、点阵构型和制备工艺. 拉伸主导型点阵材料的比强度和比刚度明显强于一般胞元材料, 在低密度时质量效率更加突出. 根据材料的基本构型特征主要介绍了三维八角点阵以及夹层点阵材料, 比较分析了熔模铸造法和冲压折叠成型工艺的特点. 总结了研究点阵材料力学性能的理论方法和试验研究成果, 研究表明缺陷对点阵材料力学性能的影响明显小于一般胞元材料. 对点阵材料在形状控制与致动、传热和数值计算方面的应用研究成果进行了介绍. 文中归纳了作者近期在炭纤维点阵复合材料方面的工作, 给出了制备炭纤维隐身点阵格栅的探索性工作. 主要包括炭纤维点阵复合材料的三维编织工艺和二维点阵格栅的嵌锁工艺以及隐身点阵格栅反射率试验测试结果. 

Development of lattice materials with high specific stiffness and strength

Lattice materials are attractive for their light-weight, high specific strength and high specific stiffness. Together with their various thermomechanical properties, they have applications in ultralight structures, as well as in impact/blast systems, heat dissipation media, acoustic isolation, microwave absorption structures and actuation. The topology criterion for stretching-dominated materials makes these lattice materials much stiffer and stronger than foams and honeycombs, especially those of low relative density. The types of lattice materials include the octet-truss lattice material and sandwich panels with differernt lattice cores, as summarized in this paper. The corresponding manufacturing methods: the investment casting method and the perforated wrought metal sheet folding method are compared. The mechanical behaviors of lattice materials are discussed in light of the experimental results, and compared with other cellular materials, especially with respect to the critical effects of imperfections to lattices and foams. The applications in actuating and heat transferring and the numerical modeling are introduced. The authors' researches in carbon fiber reinforced lattice materials are specially addressed, including the 3D interlaced carbon fiber reinforced lattice and the interlocked carbon fiber reinforced grids. The recent progresses in stealth carbon fiber reinforced grids are also outlined.