两种仿金属晶体结构晶格材料的等效弹性参数研究

Study on the Equiralent Elastic Properties of Two Kinds of Lattice Material Uimicking by Metal Crystal Structures

基于金属微观晶体结构,采用Timoshenko梁模型分别建立了体心立方(BCC)及面心立方(FCC)晶格材料等效杨氏模量理论模型,确定了晶格材料的柔度矩阵。讨论了结点效应、剪力等对晶格材料等效杨氏模量的影响。结果表明:理论模型与有限元数值模拟结果吻合较好;晶格结点对BCC及FCC晶格等效杨氏模量及剪切模量均有较大影响,忽略结点效应将低估晶格材料的线弹性力学性能;FCC比BCC晶格有更高的比杨氏模量,BCC比FCC晶格有更高的比剪切模量。此外FCC晶格材料较大多数晶格材料具有更高的抗压比刚度。

On the basis of metal crystal structures,the theoretical models of effective elastic Young’s modulus of body centered cubic(BCC)and face-centered cubic(FCC)lattice materials were established by using Timoshenko beam model,and the flexibility matrix of lattice materials was determined.The effect of nodal and shear on the Young’s modulus of lattice materials was analyzed.The results show that the theoretical model is in good agreement with the finite element numerical simulation.Moreover,the lattice nodal has a great influence on the equivalent Young's modulus and shear modulus of BCC and FCC lattices,and the elastic properties of lattice materials will be underestimated if the nodal effect is ignored.FCC has a higher specific Young's modulus than BCC lattice,while BCC has a higher specific shear modulus than FCC lattice.Furthermore,FCC lattice materials have higher compression stiffness than most of lattice materials.