Gyroid结构力学性能及数值收敛性研究

Study on Mechanics Properties and Numerical Convergence of Gyroid Cellular Structures

为了更好地揭示三周期极小曲面(TPMS)结构设计与力学性能参数之间的对应关系,研究了螺旋二十四面体Gyroid结构(GCS)不同网格参数的数值收敛性和不同排列方式的力学性能。设计了体积分数和胞元尺寸固定的GCS试件;基于单元参数变化的体素化模型,使用有限元方法对GCS进行收敛性分析;通过试件拉伸试验验证了仿真的正确性;最后以拉伸和弯曲工况研究了GCS在不同排列形式时的力学性能差异。研究结果表明:仿真分析与试验之间的抗拉强度、极限载荷误差在1.5%以内;基于体素化方法,调整雅可比参数值可显著降低收敛时的单元数量。对变厚度GCS力学性能做了定量分析,拉伸工况中,针对4×4×4结构,其等效弹性模量沿厚度方向变化最大可达14.41%;弯曲工况中,针对20×4×4结构,等效弹性模量最大差距为21.25%。

In order to reveal the corresponding relationship between TPMS structure design and mechanics property parameters,the mechanics properties of Gyroid cellular structure(GCS)with different arrangements and the numerical convergence of meshes with different parameters were studied.GCS specimens with fixed volume fraction and unit size were designed.Based on the voxelization model with changing mesh parameters,the convergence analyses of GCS were conducted by finite element method.The correctness of the simulation was verified by tensile test of specimen.Finally,the mechanics properties of the GCS in different arrangements were studied in tensile and bending conditions.Results show that the relative errors of tensile strength and load limit between simulation and experiment are all less than 1.5%.Based on the voxelization method,the number of elements during convergence may be significantly reduced by adjusting the Jacobian parameters.Quantitative analyses of mechanics properties of variable thickness GCS were conducted.In tensile tests,for 4×4×4 structures,the maximum variation of equivalent elastic modulus along the thickness direction may reach 14.41%.In bending tests,for 20×4×4 structures,the maximum difference of equivalent elastic modulus is as 21.25%.